No. XXIII.

To set a clock as within a castle, the water filling the trenches about it; which shall show, by ebbing and flowing, the hours, minutes, and seconds, and all the comprehensible motions of the heavens, and counterlibration of the earth, according to Copernicus.

NOTE.

A tide-mill was several years back exhibited in the Museum of that very ingenious mechanic, Mr. G. J. Hawkins; and a similar prime mover has been suggested for the purpose of winding a clock for a bell signal station on the Northern coast of England. An astronomical machine as described by the Marquis, must be provided with two barrels, each possessing a maintaining power sufficient for the correct performance of the whole. In addition to the line that supports the weight, or maintaining power, each barrel must be provided with a revolving pulley resembling those used for old thirty-hour clocks; with chains passing over theiraxis; and the chains being attached to large floats of wood will be alternately raised or depressed by the ebbing and flowing of the tide; and thus in succession wind up the weights which form the maintaining power of the clock. The clepsydræ, or hydraulic clock, was in general use among the ancients, and a stream of water was frequently employed to give motion to planetary machines.

How to increase the strength of a spring to such a degree as to shoot bombasses and bullets of an hundred pound weight a steeple height, and a quarter of a mile off and more, stone bow-wise, admirable for fire-works and astonishing of besieged cities, when, without warning given by noise, they find themselves so forcibly and dangerously surprised.

NOTE.

The strength of a compound spring formed of two metals may, by the application of heat, be increased to any given power.Rationale.—Iron possessing an expansive power of 1/95, and brass being only 1/60, the weaker metal will be bent by that whose power of expansion is greater, and the impulse of the spring increased in an equal ratio.

How to make a weight, that cannot take up an hundred pound, and yet shall take up two hundred pounds, and at the self same distance from the centre; and so, proportionally, to millions of pounds.

NOTE.

This is indeed paradoxical, and so completely contrary to every established principle or rule in science, that we may fairly set it down among the number of those inventions which, by partaking so highly of the marvellous, have contributed to bring the wholeCenturyinto disrepute.

To raise a weight so well and as forcibly with the drawing back of the lever, as with the thrusting it forwards; and by that means to lose no time in motion or strength. This I saw in the arsenal at Venice.

NOTE.

The mere application of a crank, such as is used for thefoot-lathe, acting upon a drum and fly-wheel,with a chain attached to move a second lever or upright sliding bar, will fully effect the object here described.

A way to remove to and fro huge weights, with a most inconsiderable strength, from place to place. For example: ten ton with ten pounds, and less; the said ten pounds not to fall lower than it makes the ten ton to advance or retreat upon a level.

NOTE.

A weight attached to an ordinary crane may be moved with the utmost facility; and it is well known that the employment of friction wheels furnishes a ready medium of conveyance for masses of iron and stone of the greatest magnitude.

A bridge, portable upon a cart, with six horses, which, in a few hours' time, may be placed over a river half a mile broad, whereon, with much expedition, may be transported, horse, foot, and cannon.

NOTE.

A portable bridge, or rather ferry boat, calculated for crossing wide and deep rivers, was frequently employed in ancient warfare, and is still used for the conveyance of horses and passengers in many parts of Europe. The apparatus for this purpose may readily be attached to the banks of the most rapid river, as it merely consists in the employment of two ropes or wires, tightened by means of a winch, on which slide pullies connected with a large floating tank or waggon, that is afterwards intended to be employed as a medium of conveyance. The apparatus being thus prepared, a communication may readily be opened by means of two cords between the opposite banks of the river.

A portable fortification, able to contain five hundred fighting men, and yet, in six hours' time, may be set up and made cannon proof, upon the side of a river or pass, with cannon mounted upon it, and as complete as a regular fortification, with half-moons and counterscarps.

NOTE.

It is difficult to attempt an elucidation of this or the following articles; but the annexed extract from theGeneral Evening Postfor 1747 appears to throw some light on No. XXX."On the 11th instant, Mr. James Allis was presented to the Royal Society, with a new invented cannon, which charges and discharges both at one time, and twenty times in a minute: he had their thanks, and a handsome present."

It is difficult to attempt an elucidation of this or the following articles; but the annexed extract from theGeneral Evening Postfor 1747 appears to throw some light on No. XXX.

"On the 11th instant, Mr. James Allis was presented to the Royal Society, with a new invented cannon, which charges and discharges both at one time, and twenty times in a minute: he had their thanks, and a handsome present."

A way, in one night's time, to raise a bulwark, twenty or thirty foot high, cannon proof, and cannon mounted upon it; with men to overlook, command and batter a town; for, though it contain but four pieces, they shall be able to discharge two hundred bullets each hour.

NOTE.

Vide the preceding Article.Since writing the above, the Editor has been called to witness the effects of highly elastic vapour applied to the propelling of leaden bullets, in an apparatus contrived by Mr. Perkins; and these destructive missile engines are capable of dischargingnearly two hundred bullets, in one sixtieth part of the time described by our author in the present Article.

Vide the preceding Article.

Since writing the above, the Editor has been called to witness the effects of highly elastic vapour applied to the propelling of leaden bullets, in an apparatus contrived by Mr. Perkins; and these destructive missile engines are capable of dischargingnearly two hundred bullets, in one sixtieth part of the time described by our author in the present Article.

A way how safely and speedily to make an approach to a castle or town-wall, and over the very ditch, at noon-day.

NOTE.

A wheel carriage, of sufficient strength to support an heavy iron tower, must first be provided. It may be constructed of thick wrought iron, with door, &c., of the same material, and hung round with sand-bags, through the interstices of which may project from six to eight small guns to protect it from musquetry. The most eligible method of moving the tower appears to be by fixing small handles to the axles of the wheels, which may be turned at pleasure by those within the walls. To prevent any attempt of the enemy who may sally forth to drag the machine within the walls of the town, &c., it will be adviseable to arm the wheels with long steel studs, which, when the handles are fastened within, will render it immoveable.This tower, though but of little use in modern warfare, appears well adapted for reconnoitring the walls of a fortified town, and, if fixed upon a hollow iron vessel, will possess the further advantage of crossing rivers and moats. Nearly similar machines are described by Vitruvius, and other authors who treat on military engineering.

This tower, though but of little use in modern warfare, appears well adapted for reconnoitring the walls of a fortified town, and, if fixed upon a hollow iron vessel, will possess the further advantage of crossing rivers and moats. Nearly similar machines are described by Vitruvius, and other authors who treat on military engineering.

How to compose an universal character, methodical and easy to be written, yet intelligible in any language; so that if an Englishman write it in English, a Frenchman, Italian, Spaniard, Irish or Welchman, being scholars, yea, Grecian or Hebritian, shall as perfectly understand it in their own tongue as if they were English, distinguishing the verbs from the nouns, the numbers, tenses, and cases, as properly expressed in their own language as it was written in English.

NOTE.

The great difficulty which the various contrivers of a universal character or philosophical language have hitherto had to encounter, from the Marquis of Worcester and Bishop Wilkins down to M. Lodowick, appears to have arisen rather from the difficulty attendant on engaging the several nations to use it, than in inventing the most convenient character.Thereal characterof Bishop Wilkins, which there is every reason to suppose strongly resembled that of his contemporary the Marquis, was repeatedly recommended by Dr. Hook, who, to engage the world in the study of it, publishedsome curious inventions of his own, tending to its illustration. But the most accurate notice on the history ofpasigraphyyet published appeared in theSpect. du Nordfor May, 1798. The anonymous author of this interesting memoir commences by a brief inquiry into the nature and utility of the universal character, and then proceeds with this very just eulogium on our immortal countryman Bacon.It is generally allowed that Lord Bacon of Verulam comprehended nearly the whole circle of human knowledge at the period in which he lived, and foresaw most of the discoveries which have since been made. He laid the foundation of an Encyclopædia, and was very near discovering various important philosophical results, such as the weight of the air, &c. If we open his book on the progress of the sciences, we shall find the notion of a pasigraphy in the chapter entitledThe Instrument of Discourse. "It is possible to invent such signs," says he, "for the communication of our thoughts, that people of different languages may, by this means, understand each other; and that each may read immediately in his own language, a book which shall be written in another." But Bacon did not think of confining this to twelve characters: on the contrary, he requires a great number, at least as many as the number of radical words; on which head he quotes the example of the Chinese; "and although," adds he, "our alphabet may appear more commodious than this method of writing, the thing itself nevertheless is well deserving of attention. The problem relates to the signs by which thoughts may be rendered current; and, as money may be struck of othermaterials as well as gold and silver, it is possible likewise to discover other signs of things as well as letters and words."Des Cartes, in his third letter to father Mercennus, discusses the invention of a Frenchman, whom he does not name, but who, by means of a certain language and an artificial writing, pretended to understand all the different idioms. He remarks on this subject, that it would be very possible to compose a short and convenient grammar, with general signs, which should render all foreign languages intelligible.In the year 1661, John Joachim Becher published a Latin folio, the title of which was "Characters for the Universal Knowledge of Languages: a Stenographic Invention hitherto unheard of." This unheard of invention consists of a method by which a native of any country may make himself understood by all foreigners by writing in his own language, and be enabled also to comprehend what they write in theirs. It was truly at that time a thing unheard of; for Becher, being the first who had given a complete treatise on this art, may be considered as the inventor.He begins his work by a series of highly interesting observations upon general grammar, and the fundamental relations of all languages with regard to each other. He gives a learned comparative table of the relations and harmony of the Latin, the Greek, the Hebrew, the Arabian, the Sclavonian, the French, and the German. This work cannot be too highly esteemed, and assuredly was not unknown to the author of the workDu Monde Primitif. A Latin dictionary then follows, in which every word corresponds with one ormore Arabic numeral figures arbitrarily taken. Every number is assumed as distinctive, or denoting the same word in all languages; and consequently nothing more is required than to compose a dictionary for each, similar to that which he has given for the Latin.There is likewise a table of declensions and conjugations, which presents certain determinate numbers for all the cases, moods, tenses, or persons. By means of this general disposition, when a Frenchman is desirous of writing to a German the following phrase,La guerre est un grand mal(war is a great evil), he seeks in his index,guerre,être,grand,mal; and he writes the correspondent numbers,13, 33, 67, 68.The sentence might be understood by these four characteristic numbers; but, to leave no room for ambiguity, he says,Guerreis the nominative case, and finds, as the characteristic of the nominative, the Arabic figure 1.Estis the third person singular of the indicative mood, present tense, of which the characteristic is 15. Togrand, and tomal, belong likewise the figure 1, for the nominative case; he will therefore write13.1 | 33.15 | 67.1 | 68.1 |where the numbers are separated by small vertical bars to prevent confusion. It may easily be conceived how, by the inverse method, the German will find in his tables the words denoted by the ciphers, which will formDer krieg ist ein grosses uebel.This invention of Becher, which is the same thing nearly with regard to language, as algebrais to arithmetic, is possessed of considerable simplicity, and even a few hours practice will render it easy. A great variety of attempts on this principle may be found in Sturmius,Essais d'Expériences Curieuses.In the same year, George Dalgaru, an Englishman, published in London a work of which the prolix title is sufficient to show its object. It runs thus, "The Art of Signs, or an Universal Character and Philosophical Language, by Means of which, Men of the most different Idioms may, in the Space of two Weeks, learn to communicate, whether by Word of Mouth or by Writing, all their Thoughts, as clearly as in their Mother Tongue. Besides which, young Persons may therein learn the Principles of Philosophy, and the Practice of true Logic, more speedily and more readily than in the ordinary philosophic Writings." The book of Dalgaru is written in Latin, and Beckman accuses him of extreme pedantry. His characters likewise were ciphers.Joachim Frisichius, professor at the Gymnasium at Riga, was employed on a similar attempt, his object being to introduce a natural, rational, and universal language, of which some sheets printed at Thorn in 1681 contain the only specimen extant. The death of the author interrupted his labours. He purposed to call his new language Ludovicean, in honour of Louis XIV., under whose patronage he pursued his labours; a prince whose generosity was extended to the learned of all countries.Athanasius Kircher also published a work on this subject, entitled "A New and Universal Polygraphia, deduced from the Art of Combination,"and by means of which, says Morhoff, (Polyhistor, l. ii. c. 5.) he who understands one language only may correspond in writing with all the nations of the earth.It would perhaps be unjust to pass in silence the little-known work of father Besnier, a Jesuit, who, in a book entitledLa Réunion des Langues, ou l'Art de les apprendre toutes par une seule, printed at Paris in 1674, has furnished many important hints for the cultivation of this branch of language.The most remarkable work, however, which has been written on this subject, is that for which we are indebted to Bishop Wilkins, the brother-in-law of Cromwell: it is entitled, "An Essay towards a Real Character and a Philosophical Language, London, 1668." It is divided into four parts: 1st, Considerations on the various languages, their defects and imperfections, from which a philosophic language ought to be exempt. 2dly, Philosophical inquiries respecting all the things and notions to which proper names ought to be assigned. 3dly, The organic science of native grammar considered as the necessary means of representing simple ideas in discourse. 4thly, The application of the general rules to every character and language. Examples, &c. This concise outline sufficiently shows the importance of the work.In his appendix, the author explains the utility of a method of writing without alphabetic characters, by means of signs, which are to be used to denote all the principal ideas, the relative attributes being designated by small strokes added at right, acute, or obtuse angles, to the right or left; &c. Of principal or chief ideas he admits butforty, under which he ranges all the others, by that means forming a series of categories. His new language is calculated to afford great facility of comprehension, and new openings to the various processes of science.After so many attempts, more or less philosophical, and of different degrees of perfection, with others probably of which we know nothing, we must not overlook the efforts of the celebrated Leibnitz. His History and Development of a Characteristic Universal Language is very generally known. Leibnitz considered his universal characteristic as the art of inventing and judging. He stated his conviction that an alphabet might be formed, and of this alphabet such words as would afford a language capable of giving mathematical precision to all the sciences. "Men may thus acquire," says he, "as it were, a new organ, which would add energy to their moral faculties, as the microscopic lens increases the power of the eye. The compass is not more highly valuable to the navigator, than this philosophical language would be to him who embarks on the sea of reason and experiments, which is now so full of danger."In concluding this brief sketch, it may be enough to notice the ingenious method of the Abbé de l'Epée, who, by means of various gestures, dictated to his various deaf and dumb pupils certain discourses, which they wrote with equal readiness in four languages.

Thereal characterof Bishop Wilkins, which there is every reason to suppose strongly resembled that of his contemporary the Marquis, was repeatedly recommended by Dr. Hook, who, to engage the world in the study of it, publishedsome curious inventions of his own, tending to its illustration. But the most accurate notice on the history ofpasigraphyyet published appeared in theSpect. du Nordfor May, 1798. The anonymous author of this interesting memoir commences by a brief inquiry into the nature and utility of the universal character, and then proceeds with this very just eulogium on our immortal countryman Bacon.

It is generally allowed that Lord Bacon of Verulam comprehended nearly the whole circle of human knowledge at the period in which he lived, and foresaw most of the discoveries which have since been made. He laid the foundation of an Encyclopædia, and was very near discovering various important philosophical results, such as the weight of the air, &c. If we open his book on the progress of the sciences, we shall find the notion of a pasigraphy in the chapter entitledThe Instrument of Discourse. "It is possible to invent such signs," says he, "for the communication of our thoughts, that people of different languages may, by this means, understand each other; and that each may read immediately in his own language, a book which shall be written in another." But Bacon did not think of confining this to twelve characters: on the contrary, he requires a great number, at least as many as the number of radical words; on which head he quotes the example of the Chinese; "and although," adds he, "our alphabet may appear more commodious than this method of writing, the thing itself nevertheless is well deserving of attention. The problem relates to the signs by which thoughts may be rendered current; and, as money may be struck of othermaterials as well as gold and silver, it is possible likewise to discover other signs of things as well as letters and words."

Des Cartes, in his third letter to father Mercennus, discusses the invention of a Frenchman, whom he does not name, but who, by means of a certain language and an artificial writing, pretended to understand all the different idioms. He remarks on this subject, that it would be very possible to compose a short and convenient grammar, with general signs, which should render all foreign languages intelligible.

In the year 1661, John Joachim Becher published a Latin folio, the title of which was "Characters for the Universal Knowledge of Languages: a Stenographic Invention hitherto unheard of." This unheard of invention consists of a method by which a native of any country may make himself understood by all foreigners by writing in his own language, and be enabled also to comprehend what they write in theirs. It was truly at that time a thing unheard of; for Becher, being the first who had given a complete treatise on this art, may be considered as the inventor.

He begins his work by a series of highly interesting observations upon general grammar, and the fundamental relations of all languages with regard to each other. He gives a learned comparative table of the relations and harmony of the Latin, the Greek, the Hebrew, the Arabian, the Sclavonian, the French, and the German. This work cannot be too highly esteemed, and assuredly was not unknown to the author of the workDu Monde Primitif. A Latin dictionary then follows, in which every word corresponds with one ormore Arabic numeral figures arbitrarily taken. Every number is assumed as distinctive, or denoting the same word in all languages; and consequently nothing more is required than to compose a dictionary for each, similar to that which he has given for the Latin.

There is likewise a table of declensions and conjugations, which presents certain determinate numbers for all the cases, moods, tenses, or persons. By means of this general disposition, when a Frenchman is desirous of writing to a German the following phrase,La guerre est un grand mal(war is a great evil), he seeks in his index,guerre,être,grand,mal; and he writes the correspondent numbers,

13, 33, 67, 68.

The sentence might be understood by these four characteristic numbers; but, to leave no room for ambiguity, he says,Guerreis the nominative case, and finds, as the characteristic of the nominative, the Arabic figure 1.Estis the third person singular of the indicative mood, present tense, of which the characteristic is 15. Togrand, and tomal, belong likewise the figure 1, for the nominative case; he will therefore write

13.1 | 33.15 | 67.1 | 68.1 |

where the numbers are separated by small vertical bars to prevent confusion. It may easily be conceived how, by the inverse method, the German will find in his tables the words denoted by the ciphers, which will formDer krieg ist ein grosses uebel.

This invention of Becher, which is the same thing nearly with regard to language, as algebrais to arithmetic, is possessed of considerable simplicity, and even a few hours practice will render it easy. A great variety of attempts on this principle may be found in Sturmius,Essais d'Expériences Curieuses.

In the same year, George Dalgaru, an Englishman, published in London a work of which the prolix title is sufficient to show its object. It runs thus, "The Art of Signs, or an Universal Character and Philosophical Language, by Means of which, Men of the most different Idioms may, in the Space of two Weeks, learn to communicate, whether by Word of Mouth or by Writing, all their Thoughts, as clearly as in their Mother Tongue. Besides which, young Persons may therein learn the Principles of Philosophy, and the Practice of true Logic, more speedily and more readily than in the ordinary philosophic Writings." The book of Dalgaru is written in Latin, and Beckman accuses him of extreme pedantry. His characters likewise were ciphers.

Joachim Frisichius, professor at the Gymnasium at Riga, was employed on a similar attempt, his object being to introduce a natural, rational, and universal language, of which some sheets printed at Thorn in 1681 contain the only specimen extant. The death of the author interrupted his labours. He purposed to call his new language Ludovicean, in honour of Louis XIV., under whose patronage he pursued his labours; a prince whose generosity was extended to the learned of all countries.

Athanasius Kircher also published a work on this subject, entitled "A New and Universal Polygraphia, deduced from the Art of Combination,"and by means of which, says Morhoff, (Polyhistor, l. ii. c. 5.) he who understands one language only may correspond in writing with all the nations of the earth.

It would perhaps be unjust to pass in silence the little-known work of father Besnier, a Jesuit, who, in a book entitledLa Réunion des Langues, ou l'Art de les apprendre toutes par une seule, printed at Paris in 1674, has furnished many important hints for the cultivation of this branch of language.

The most remarkable work, however, which has been written on this subject, is that for which we are indebted to Bishop Wilkins, the brother-in-law of Cromwell: it is entitled, "An Essay towards a Real Character and a Philosophical Language, London, 1668." It is divided into four parts: 1st, Considerations on the various languages, their defects and imperfections, from which a philosophic language ought to be exempt. 2dly, Philosophical inquiries respecting all the things and notions to which proper names ought to be assigned. 3dly, The organic science of native grammar considered as the necessary means of representing simple ideas in discourse. 4thly, The application of the general rules to every character and language. Examples, &c. This concise outline sufficiently shows the importance of the work.

In his appendix, the author explains the utility of a method of writing without alphabetic characters, by means of signs, which are to be used to denote all the principal ideas, the relative attributes being designated by small strokes added at right, acute, or obtuse angles, to the right or left; &c. Of principal or chief ideas he admits butforty, under which he ranges all the others, by that means forming a series of categories. His new language is calculated to afford great facility of comprehension, and new openings to the various processes of science.

After so many attempts, more or less philosophical, and of different degrees of perfection, with others probably of which we know nothing, we must not overlook the efforts of the celebrated Leibnitz. His History and Development of a Characteristic Universal Language is very generally known. Leibnitz considered his universal characteristic as the art of inventing and judging. He stated his conviction that an alphabet might be formed, and of this alphabet such words as would afford a language capable of giving mathematical precision to all the sciences. "Men may thus acquire," says he, "as it were, a new organ, which would add energy to their moral faculties, as the microscopic lens increases the power of the eye. The compass is not more highly valuable to the navigator, than this philosophical language would be to him who embarks on the sea of reason and experiments, which is now so full of danger."

In concluding this brief sketch, it may be enough to notice the ingenious method of the Abbé de l'Epée, who, by means of various gestures, dictated to his various deaf and dumb pupils certain discourses, which they wrote with equal readiness in four languages.

To write with a needle and thread, white, or any other colour, upon white, or any othercolour, so that one stitch shall significantly show any letter, and as readily and as easily show the one letter as the other, and fit for any language.

NOTE.

Vide Article LXXV.

To write by a knotted silk string, so that every knot shall signify any letter, with comma, full-point, or interrogation; and as legible as with pen and ink upon white paper.

NOTE.

This very ingenious mode of secret writing is the most simple of any suggested by our author. A silk string of considerable length having been provided, it will be necessary to furnish the persons corresponding with a key or graduated gauge, by means of which the writing will be rendered intelligible. Having procured a duplicate or corresponding gauge it may then be commenced, 1/16 of an inch being allowed for the first letter, 1/4 for the second, 3/8 for the third, and so on, in equal proportions, through the whole alphabet. Should this arrangement be found to extend theline to an inconvenient length, it may be advisable to form a certain number of changes on three different lengths, as in No. LII.; though the former way is the least difficult.

The like by the fringe of gloves.

NOTE.

The principle of this and the four following Articles is the same as the preceding, with this difference, that in the first, the letters, or words, are formed by knotting the fringe, to which the gauge is afterwards applied; in the second, and most desirable way, the beads are set to the required distance; by the third, the gloves are pierced or pricked in rows, according to the divisions on the gauge; and by the fourth and fifth, the rows of parallel holes in a sieve or lantern are stopped at the required distances, and the gauge applied as before.

By stringing of bracelets.

By pinked gloves.

By holes in the bottom of a sieve.

By a lattin or candlestick lantern.

By thesmell.

NOTE.

Pegs of sandal, cedar, and rose woods, may be so varied, that a person writing in the dark will, by the smell, readily distinguish the formation of words and sentences.

By thetaste.

NOTE.

For writing by thetaste, it will be necessary to immerse an equal number of the pegs or beads in weak solutions of alum, aloes, common salt, or any other liquid whose taste is sufficiently pungentor aromatic, to be distinguished when dry, on applying the tongue to them for that purpose.

By thetouch.

By these three senses, as perfectly, distinctly, and unconfusedly, yea, as readily as by the sight.

NOTE.

This object may be readily attained by the use of raised moveable types and the heavy pressure of an iron pen or mallet.A mode of corresponding by the touch has been suggested by M. Haüy, and by this means the blind have been fully instructed, not only in the rudiments of language, but also in the liberal arts and sciences. M. Haüy's method of preparing the books, &c., which is simple and easy of attainment, is as follows: when the types have been arranged and fixed, a page of very strong paper is moistened, so as to be capable of receiving and retaining impressions, and laid upon the types; and then by the operation of a press or hammer, frequently repeated over the surface, the impression of the type is made to rise on the opposite side of the paper; and it continues, when dry, not only "obvious to the sight," but to the touch, and is not easily effaced. On the upper side of the paper,the letters appear in their proper position; and by their sensible elevation above the common surface, the blind may easily read them with their fingers. For epistolary correspondence it will be necessary to moisten the paper and use a metal pen.

This object may be readily attained by the use of raised moveable types and the heavy pressure of an iron pen or mallet.

A mode of corresponding by the touch has been suggested by M. Haüy, and by this means the blind have been fully instructed, not only in the rudiments of language, but also in the liberal arts and sciences. M. Haüy's method of preparing the books, &c., which is simple and easy of attainment, is as follows: when the types have been arranged and fixed, a page of very strong paper is moistened, so as to be capable of receiving and retaining impressions, and laid upon the types; and then by the operation of a press or hammer, frequently repeated over the surface, the impression of the type is made to rise on the opposite side of the paper; and it continues, when dry, not only "obvious to the sight," but to the touch, and is not easily effaced. On the upper side of the paper,the letters appear in their proper position; and by their sensible elevation above the common surface, the blind may easily read them with their fingers. For epistolary correspondence it will be necessary to moisten the paper and use a metal pen.

How to vary each of these, so that ten thousand may know them, and yet keep the understanding part from any but their correspondent.

NOTE.

This may be effected by changing the order of their arrangement, which can only be ascertained by a previous examination of a key chosen for that purpose.

To make a key of a chamber door, which to your sight hath its wards and rose-pipe but paper thick, and yet at pleasure, in a minute of an hour, shall become a perfect pistol, capable to shoot through a breastplate, commonly of carabine proof, with prime, powder, and fire-lock, undiscoverable in a stranger's hand.

NOTE.

Therose-pipemust in this case be formed like the sliding tubes of a telescope; that next the wards being furnished with a screw at the inner and capable of holding the whole of them together. A small quantity of detonating powder being first placed within, the pipe may be readily discharged by tightening of the screw.

How to light a fire and a candle, at what hour of the night one awaketh, without rising or putting one's hand out of bed. And the same thing to be a serviceable pistol at pleasure; yet, by a stranger, not knowing the secret, seemeth but a dexterous tinder-box.

NOTE.

The pistol tinder-box may readily be made to perform the whole of what is here described. A bell rope attached to the trigger will suffice to elicit fire, which, communicating with a quick-match or fusee, will quickly ignite and produce the required light. If the fire is previously prepared with wood or some other combustible material, and a small quantity of inflammable spirits sprinkled over it, the slightest spark will throw the whole into a blaze. For the latter qualification mentionedby the noble author, a pistol barrel may easily be secreted under the tinder.The inflammable air-lamp contrived by Volta possesses similar properties: a stream of hydrogen gas being inflamed by the spark from an electrophorus.—VideBrande's Manual of Chemistry, vol. i. p. 240.

The inflammable air-lamp contrived by Volta possesses similar properties: a stream of hydrogen gas being inflamed by the spark from an electrophorus.—VideBrande's Manual of Chemistry, vol. i. p. 240.

How to make an artificial bird to fly which way and as long as one pleaseth, by or against the wind, sometimes chirping, other times hovering, still tending the way it is designed for.

NOTE.

In the year 1810, two birds were exhibited at the museum of the late Mr. Merlin; these performed nearly all the evolutions described by the Author: with this exception, however, that they were supported by fine wires; and a similar bird was exhibited in London in the year 1786.—Vide77th Art. in the Century.

To make a ball of any metal, which, thrown into a pool or pail of water, shall presently rise from the bottom, and constantly show,by the superficies of the water, the hour of the day or night, never rising more out of the water than just to the minute it showeth of each quarter of the hour; and if by force kept under water, yet the time is not lost, but recovered as soon as it is permitted to rise to the surface of the water.

NOTE.

A metal ball graduated on the surface, in the same manner as the index stem to an hydrometer, with a balance to preserve its equilibrium, must first be exhausted of air, which being effected, the water may be allowed to enter by a small aperture, and it will gradually sink till the vessel is filled: this, if the ball is about 12 inches in diameter and the aperture of a proportionate size, will not take place in less than twelve hours.

A screwed ascent, instead of stairs, with fit landing places to the best chambers of each story, with back stairs within thenoelof it, convenient for servants to pass up and down to the inward rooms of them, unseen and private.

NOTE.

It is most probable that the Marquis here alludes to the geometrical staircase now in such general use, with the addition of a small flight of stairs in the centre, in lieu of the common handrail, which being surrounded by a partition of boards, would readily serve as a private communication with the upper stories: sufficient space being left between the ceiling and under side of the principal staircase to admit of a passage to the inner rooms. Since writing the above, the Editor has seen a more explicit account of this species of staircase. It occurs in "Evelin's Memoirs," vol. i. page 59, and forms part of that learned and amusing author's tour through France in 1644. The following is an extract. "Quitting our barke, we hired horses to Blois, by way of Chambourg, a famous house of yeKing's, built by Francis I. in the middle of a solitary parke, full of deere; the enclosure is a wall. I was particularly desirous of seeing this palace, from the extravagance of the design, especially thestayrecase, mentioned by Palladio. It is said that 1800 workmen were constantly employed in this fabric for twelve yeares; if so, it is wonderfull that it was not finish'd, it being no greater than divers gentlemen's houses in England, both for roome or circuit. The carvings are very rich and full. The stayrecase is devised wthfour entries or ascents, which cross one another, so that though four persons meete, they never come in sight, but by small loope-holes, till they land. It consists of 274 steps (as I remember), andis an extraordinary worke, but of far greater expense than use or beauty."

A portable engine, in way of a tobacco-tongs, whereby a man may get over a wall, or get up again, being come down, finding the coast proveth insecure for him.

NOTE.

It is not very easy to discover to what the noble author here alludes: if bytobacco-tongs, he means a combination of levers such as is used by gardeners, to gather choice fruit or lop the upper boughs of trees, the mode of applying them is extremely easy. A number of short pieces of brass, jointed together, and made to resemble a row oftrelliswork, may, by distending the joints in an horizontal direction, be made to go in the smallest compass; and again, by closing the arms, the machine will be elevated. An ingenious mechanic has constructed afire-escapeupon this principle, of which a model is preserved in the Museum of the Society for the Encouragement of Arts, &c.

A complete light portable ladder, which taken out of one's pocket, may be by himselffastened an hundred feet high to get up by from the ground.

NOTE.

A number of light brass tubes, each having a socket to receive the end of the preceding joint, may be raised to any given height, and with the assistance of small loops of cord will fully answer the purpose here described. It will be necessary to have a small stud at one end of each joint, with a narrow slit at the end of the following tube to receive it, which being carried on in a right angle for about twice its width, will on being turned round serve as a key to prevent the joints separating.

A rule of gradation, which, with ease and method, reduceth all things to a private correspondence, most useful for secret intelligence.

NOTE.

VideArticle V.

How to signify words, and a perfect discourse, by jangling of bells of any parishchurch, or by any musical instrument within hearing, in a seeming way of tuning it, or of an unskilful beginner.

NOTE.

By varying the order of arrangement, the whole alphabet may readily be rung on three bells; and these, being formed into sentences by short pauses between each word, will fully serve for distant conversation. For musical instruments, it is merely changing keys for bells, and the same purpose may be answered without the trouble of forming changes upon so small a number of fixed tones. A table is subjoined, by the use of which a combination of three bells is made to express the whole alphabet:

Arepresented by111B112C113D121E122F123G131H132I133K211L212M213N221O222P223Q231R232S233T311V312U313W321X322Y323Z333

A way how to make hollow and cover a water-screw, as big and as long as one pleaseth, in an easy and cheap way.

NOTE.

A leathern water-pipe, such as is used by the firemen, being nailed in a spiral form round a long circular pole, is the cheapest and most simple method yet discovered of making the Archimedean screw.

How to make a water-screw tight, and yet transparent, and free from breaking; but so clear, that one may palpably see the water, or any heavy thing, how and why it is mounted by turning.

NOTE.

This may be readily effected either by making a coarse screw in the usual manner, and covering it with horn, or by fitting a spiral tube of glass on a wooden cylinder, and filling up the interstices with wax or any hard cement so as to projectbeyond the glass tube: this appears the most eligible method, though the former is the most economical.M. A. Rochon has likewise proposed a most ingenious substitute for the use of horn in the construction of the Archimedean screw, and other hydraulic instruments. It is formed (like the safety lamp of Sir H. Davy) of a coarse wire gauze which, on being immersed in pure fish-glue or size, forms when varnished a cheap and durable substitute for the use of glass.

M. A. Rochon has likewise proposed a most ingenious substitute for the use of horn in the construction of the Archimedean screw, and other hydraulic instruments. It is formed (like the safety lamp of Sir H. Davy) of a coarse wire gauze which, on being immersed in pure fish-glue or size, forms when varnished a cheap and durable substitute for the use of glass.

A double water-screw, the innermost to mount the water, and the outermost for it to descend more in number of threads, and consequently in quantity of water, though much shorter than the innermost screw, by which the water ascendeth, a most extraordinary help for the turning of the screw to make the water rise.

NOTE.

This appears one of those extraordinary slight of hand discoveries in which the noble author is too apt to indulge; and though we may readily admit that two water-screws may be most advantageously employed in turning of any water-wheel,where an abundant supply is found at the top of the machine, it yet requires a greater share of penetration than we choose to take credit for, to discover how a larger quantity of water can descend than has been previously raised, or, if so, how the machine could be at all applied to theraisingof water.

To provide and make, that all the weights of the descending side of a wheel shall be perpetually farther from the centre than those of the mounting side, and yet equal in number and heft of the one side as the other. A most incredible thing, if not seen, but tried before the late king of happy and glorious memory, in the Tower, by my directions; two extraordinary ambassadors accompanying his Majesty, and the Duke of Richmond, and Duke Hamilton, with most of the court attending him. The wheel was fourteen feet over, and forty weights of fifty pounds a-piece. Sir William Belford, then Lieutenant of the Tower, can testify it, with several others. They all saw, that no sooner these great weightspassed the diameter line of the upper side, but they hung a foot farther from the centre; nor no sooner passed the diameter line of the lower side, but they hung a foot nearer. Be pleased to judge the consequence.

NOTE.

The celebrated problem of a self-impelling power, though denied by Huygens and de la Hire, who have attempted to demonstrate its fallacy, has yet been supported by some of the most celebrated among the ancient as well as modern philosophers. Innumerable have been the machines to which the idea ofthe perpetual motionhas given birth; but the most celebrated among the moderns is theOrffyrean wheel. This machine, according to the description given of it by M. Grævesande, in hisŒuvres Philosophiques, consisted of a large circular wheel or drum, twelve feet in diameter, and fourteen inches in depth. It was composed of a number of thin deals, the spaces between which were covered with wax cloth, in order to conceal the interior parts of it. On giving the wheel, which rested on the two extremities of an iron axis, a slight impulse in either direction, its motion was gradually accelerated; so that after two or three revolutions it is said to have acquired so great a velocity as to make twenty-five or more turns in a minute: and it appears to have preserved this rapid motion for the space of two months, during which time the Landgrave of Hesse, in whose chamberit was placed to prevent a possibility of collusion, kept his own seal on the outer door. At the end of that time it was stopped to prevent the wear of the materials. Grævesande, who had been an eye-witness to the performance of this machine, examined all the external parts of it, and was convinced that there could not be any communication between it and the adjacent rooms. Orffyreus, however, having been informed of the ill-timed curiosity of the professor, and incensed at the refusal of a premium oftwenty thousand pounds, which he had made asine quâ nonfor disclosing the mechanism of its construction, broke the whole apparatus into atoms, and his life was soon after sacrificed to chagrin at his disappointment. The analogy between the Marquis's description and the Orffyrean wheel is sufficiently evident; and the experiment having been made in the Tower, more than fifty years prior to the attempt of the German mechanic, it is more than probable that the idea was derived from the noble author's work.

An ebbing and flowing water-work in two vessels, into either of which, the water standing at a level, if a globe be cast in, instead of rising, it presently ebbeth, and so remaineth, until a like globe be cast into the other vessel, which the water is no soonersensible of, but that the vessel presently ebbeth, and the other floweth, and so continueth ebbing and flowing, until one or both the globes be taken out, working some little effect besides its own motion, without the help of any man within sight or hearing: but if either of the globes be taken out, with ever so swift or easy a motion, at that instant the ebbing and flowing ceaseth; for if, during the ebbing, you take out the globe, the water of that vessel presently returneth to flow, and never ebbeth after, until the globe be returned into it, and then the motion beginneth as before.

NOTE.

This invention, which is evidently more a matter of curiosity than of real utility, is no doubt effected upon the principle of an ebbing and flowing spring; the throwing in of the ball, by causing a commensurate rise of the water, fills a syphon, and sets the water-work in motion, but as the effect of this would cease after the two vessels attained an equilibrium, the machine must be assisted by a moving power attached to one or both of the vessels, as the Marquis merely says, that it may be performed "without the help of any manwithin sight or hearing."

How to make a pistol to discharge a dozen times with one loading, and without so much as once new priming requisite; or to change it out of one hand into the other, or stop one's horse.

NOTE.

An attentive examination of this and the subsequent articles has suggested what appears an improvement of considerable importance in the principle of modern fire-arms. The expense attendant on the manufacture of double barrelled guns, and the inconvenience which arises from their additional weight, have hitherto prevented their coming into general use, though their utility in the field is very generally allowed. An economical gun uniting all the advantages of the one, with the lightness and portability of the other, must therefore be considered as a desideratum of the first importance. To effect this, a common gun barrel must be pierced with the required number of touchholes, at a sufficient distance to allow of an equal number of charges. A detonating magazine gunlock may then be made to slide on the lower part of the barrel, with a parallel ratchet and click to fix precisely opposite the touchhole to be inflamed. The gun must then be loaded by a graduated ramrod, the powder of each charge being brought opposite its propertouchhole. After the first discharge, the cock must be moved back one tooth of the ratchet, and this motion continued till the whole are exploded, each hole being covered successively by a plate attached to the lock.No. 60 is evidently performed by filling a cylindrical flask, made the same size as the barrel, with the required number of charges and afterwards forcing the whole of them into the barrel.Nos. 61 and 67 may be performed by filling a flask previously made to fit the breech of the musket, and forcing forward each successive charge by a screw or lever, in the same manner as the charging is effected in a magazine air-gun.

No. 60 is evidently performed by filling a cylindrical flask, made the same size as the barrel, with the required number of charges and afterwards forcing the whole of them into the barrel.

Nos. 61 and 67 may be performed by filling a flask previously made to fit the breech of the musket, and forcing forward each successive charge by a screw or lever, in the same manner as the charging is effected in a magazine air-gun.

Another way, as fast and effectual, but more proper for carabines.

VideArticle LVIII.

A way, with a flask appropriated unto it, which will furnish either pistol or carabine with a dozen charges in three minutes' time, to do the whole execution of a dozen shots, as soon as one pleaseth, proportionably.

VideArticle LVIII.

A third way, and particularly for muskets, without taking them from their rests to charge or prime, to a like execution, and as fast as the flask, the musket containing but one charge at a time.

VideArticle LVIII.

A way for a harquebuss, a crock, or ship musket, six upon a carriage, shooting with such expedition, as, without danger, one may charge, level, and discharge them sixty times in a minute of an hour, two or three together.

VideArticle LVIII.

A sixth way, most excellent forsakers, differing from the other, yet as swift.

VideArticle LVIII.

A seventh, tried and approved before the late king (of ever blessed memory), and an hundred lords and commons, in a cannon of eight inches and half a quarter, to shoot bullets of sixty-four pounds weight, and twenty-four pounds of powder, twenty times in six minutes; so clear from danger, that, after all were discharged, a pound of butter did not melt, being laid upon the cannon britch, nor the green oil discoloured that was first anointed and used between the barrel thereof, and the engine having never in it, nor within six foot, but one charge at a time.

VideArticle XXIX.

A way that one man, in the cabin, may govern a whole side of ship muskets, to the number (if need require) of two or three thousand shots.

NOTE.

The plan of this and the following Articles, though not of much practical utility, may yet be acted upon with a certainty of success. The powder may be ignited by the means of a powerful electrifying machine made to communicate with each separate piece, and the charging must be performed by conducting wires or rods made to act upon the magazine lever described in Article LVIII.Since writing the above, an article has appeared on the subject in one of the French Journals, of which the following is a translation: At two o'clock in the afternoon M. Bouche made an experiment in theJardin des Plantesat Paris, to try the effect of electricity applied to gun batteries. Instead of guns he had fixed about one hundred rockets on long sticks, disposed in the garden. The rockets were all connected by an iron wire, and the same spark produced a spontaneous explosion. The concourse of people was very great, the weather being remarkably fine. This new invention is not intended to increase the destructive powers of those formidable weapons; but it is expected to afford the means of using them without exposing gunners to the fire of the enemy.

Since writing the above, an article has appeared on the subject in one of the French Journals, of which the following is a translation: At two o'clock in the afternoon M. Bouche made an experiment in theJardin des Plantesat Paris, to try the effect of electricity applied to gun batteries. Instead of guns he had fixed about one hundred rockets on long sticks, disposed in the garden. The rockets were all connected by an iron wire, and the same spark produced a spontaneous explosion. The concourse of people was very great, the weather being remarkably fine. This new invention is not intended to increase the destructive powers of those formidable weapons; but it is expected to afford the means of using them without exposing gunners to the fire of the enemy.

A way, that against the several avenues to a fort or castle, one man may charge fiftycannons, playing and stopping when he pleaseth, though out of sight of the cannon.

Videlast Article.

A rare way likewise for muskettoons, fastened to the pommel of the saddle, so that a common trooper cannot miss to charge them, with twenty or thirty bullets at a time, even in full career.

NOTE BY THE AUTHOR.

When first I gave my thoughts to make guns shoot often, I thought there had been but one only exquisite way inventible; yet, by several trials, and much charge, I have perfectly tried all these.

An admirable and most forcible way to drive up water by fire, not by drawing or sucking it upwards, for that must be, as the philosopher calleth it,infra sphæram activitatis, which is but at such a distance.But this way hath no bounder, if the vessels be strong enough; for, I have taken a piece of a whole cannon, whereof the end was burst, and filled it three-quarters full, stopping and screwing up the broken end, as also the touchhole; and making a constant fire under it, within twenty-four hours it burst and made a great crack: so that having found a way to make my vessels, so that they are strengthened by the force within them, and the one to fill after the other, have seen the water run like a constant fountain stream, forty feet high; one vessel of water, rarefied by fire, driveth up forty of cold water: and a man that tends the work is but to turn two cocks, that one vessel of water being consumed, another begins to force and refill with cold water, and so successively, the fire being tended and kept constant, which the self-same person may likewise abundantly perform in the interim between the necessity of turning the said cocks.

NOTE.

VideArticle C., to which is prefixed a brief historical and descriptive account of that stupendous machine, the Steam-engine.

A way how a little triangle and screwed key shall be capable and strong enough to bolt and unbolt, round about a great chest, an hundred bolts through fifty staples, two in each, with a direct contrary motion, and as many more from both sides and ends, and at the self-same time shall fasten it to the place, beyond a man's natural strength to take it away; and, in one and the same turn, both locketh and openeth it.

NOTE.

This invention, with its two following modifications, is evidently intended to operate on the principle of applying a screw for the purpose of forcing thelock bolt, in lieu of using the handle of the key as a lever for that purpose. That this plan might be applied to locks generally, there can be no doubt, and by a similar contrivance the large keys at present in use for outer doors, iron chests, &c. might be advantageously reduced to the size described by the noble author. By employing the escutcheon mentioned in No. LXXII. these locks would be equally safe and much more simplethan those in common use. For the latter part of the Article, any ingenious smith may make a lock with an hundred bolts; and to fasten it to the place, the power of a screw key is abundantly sufficient to force an iron bar through a staple previously fixed in the floor.

A key, with a rose-turning pipe, and two roses pierced through endwise; together with several handsomely contrived wards, which may likewise do the same effects.

A key, perfectly square, with a screw turning within it, and more conceited than either of the rest, and no heavier than the triangle screwed key, and doth the same effects.

An escutcheon, to be placed before any of these locks with these properties.

1. The owner (though a woman) may, with her delicate hand, vary the ways ofcoming to open the lock ten millions of times, beyond the knowledge of the smith that made it, or of me who invented it.2. If a stranger open it, it setteth an alarm a going, which the stranger cannot stop from running out; and, besides, though none should be within hearing, yet it catcheth his hand, as a trap doth a fox; and though far from maiming him, yet it leaveth such a mark behind it, as will discover him if suspected; the escutcheon, or lock, plainly shewing what money he hath taken out of the box, to a farthing, and how many times opened since the owner had been at it.

1. The owner (though a woman) may, with her delicate hand, vary the ways ofcoming to open the lock ten millions of times, beyond the knowledge of the smith that made it, or of me who invented it.

2. If a stranger open it, it setteth an alarm a going, which the stranger cannot stop from running out; and, besides, though none should be within hearing, yet it catcheth his hand, as a trap doth a fox; and though far from maiming him, yet it leaveth such a mark behind it, as will discover him if suspected; the escutcheon, or lock, plainly shewing what money he hath taken out of the box, to a farthing, and how many times opened since the owner had been at it.

NOTE.

The two principal properties of this escutcheon may be readily contrived; and the first of them has, in fact, been already applied to a very ingenious padlock, invented by Mr. Marshall, and for which the Society of Arts voted him a reward of ten guineas. In Mr. M.'s escutcheon the letters or figures commonly used in the ring padlock allow an almost endless variety of changes, and the owner may in one minute alter the arrangement in such a manner that even the maker would experience as much difficulty to open it, as anentire stranger to its construction. To render the combination of letters variable, the characters must not be engraved upon the outside of the rollers themselves, but upon a thin brass hoop made to fit on its outer surface; and a spring fastened to the roller, and pressing upon the inside of the hoop, will cause a sufficient degree of friction to make them move together.The other part of this invention is equally simple with the preceding. An alarum, such as is attached to a clock, may easily be wound up prior to closing the box; and the lid provided with a chamfered bolt or staple, capable of effecting its discharge when the box is opened.To register the amount of money taken from the box, it will be necessary either to place each distinct piece of money in separate divisions, or to put a number together in one deep recess capable of admitting but one piece to pass at a time. As the pieces are shaken out, they will in their passage raise a lever capable of moving a wheel one division in the passage of each piece.The Bank of England have a method somewhat similar for registering the number of notes worked from the printing press of that establishment.

The other part of this invention is equally simple with the preceding. An alarum, such as is attached to a clock, may easily be wound up prior to closing the box; and the lid provided with a chamfered bolt or staple, capable of effecting its discharge when the box is opened.

To register the amount of money taken from the box, it will be necessary either to place each distinct piece of money in separate divisions, or to put a number together in one deep recess capable of admitting but one piece to pass at a time. As the pieces are shaken out, they will in their passage raise a lever capable of moving a wheel one division in the passage of each piece.

The Bank of England have a method somewhat similar for registering the number of notes worked from the printing press of that establishment.

A transmittable gallery over any ditch or breach in a town-wall, with a blind and parapet, cannon proof.

A door, whereof the turning of a key, with the help and motion of the handle, makes the hinges to be of either side, and to open either inward or outward, as one is to enter or to go out, or to open in half.

NOTE.

By making the handle act on a lever communicating with the hinges, they may be raised from their sockets on the required side; and to open in half, it is merely necessary to joint them in the centre.

How a tape or riband-weaver may set down a whole discourse, without knowing a letter, or interweaving any thing suspicious of other secret than a new-fashioned riband.

NOTE.

The evident analogy between this Article and No. XXXIII. will be apparent on the slightest view, and in general principle it is similar to Nos. XXXIV. XXXV., &c. It may be performed either by making the stitches of a given length,varying the distance to distinguish the different letters of the alphabet; or, by any arbitrary shape which may be previously agreed upon by the parties corresponding. These arrangements being made, the silk weaver will have nothing more to do, than set his loom to the required pattern.

How to write in the dark, as straight as by day or candle-light.

NOTE.

Two planes of ebony of equal length and breadth, similar to the parallel ruler, and joined at each end by racks, the side of which being graduated to the width of the line intended will serve as a certain guide, and by the use of this instrument a blind person may write with the greatest accuracy. If ivory tablets or a slate is used, a fine wire drawn with a steel point may be readily felt by the point of the pencil.

How to make a man to fly: which I have tried with a little boy of ten years old, in a barn, from one end to the other, on a hay-mow.

NOTE.

Innumerable are the schemes that have been proposed by the learned at different periods, to enable man to support himself in the air by the means of artificial wings, &c. and some, indeed, of these ingenious contrivances have formed the labours of the most distinguished mechanical geniuses, which are recorded in the early annals of science.Bacon, and an Italian priest named Francisco Lana, endeavoured to accomplish it by means of two thin hollow globes, exhausted of air, which being considerably lighter than that fluid, were intended to sustain a chair suspended to their lower extremity, and on which the aeronaut might be seated. But Dr. Hook, in a work published some time after theProdromoof Lana, plainly showed the fallacy of the attempt, though without in the least attempting to deny the possibility of eventually effecting this object.Bishop Wilkins, who was also a disciple of the flying system, describes a species of land-sailing vessels or chariots, which were then commonly used in China: and it is rather a curious fact that a German Count, possessing as much of modesty as the generality of foreign mechanics, has lately given to the public, as his own, an invention which has been known in Europe, and occasionally employed in Asia, for the last four hundred years.But of all the plans that have hitherto been devised, those only which have mechanic power as their basis appear to have any chance of success. This may be considered as an unerringdatumto guide the future experimentalist, the certainty of which is fully demonstrated by a comparison ofthe powers of the human frame with those of the feathered tribe: for it has been calculated by an ingenious anatomist, that the muscles which move the wings downwards in a bird in many instances, constitute not less than the sixth part of the weight of the whole body; while those of a man are not one hundredth part so large. By the use of springs, however, wound to a certain degree of tension, prior to embarking upon the intended expedition, and acting upon cranks working the wings, the same power as that possessed by the feathered race may be obtained, and the springs may be readily made to draw more than fifty times their weight. By this means a whalebone, or other light carriage, may be raised, though it would be but for a short time, as it would not be in the power of the aëronaut to wind the springs so quick as the machine would require.From this, then, it will be seen that, to produce the effect necessary for this species of navigation, it is only requisite to have a first mover, which will produce more power, in a given time, in proportion to its weight, than the animal system of muscles.High pressure steam-engines have been made to operate by expansion only, and they, it appears, might be constructed so as to be light enough for this purpose. In that case, however, it will be evident that the usual plan of a large boiler must be given up, and the principle of injecting a proper charge of water into a series of tubes, forming the cavity of the fire, must be adopted in lieu of it.The following estimate will show the probableweight of such an engine with its charge for one hour.lbs.The engine itself, from 90 to100Weight of inflamed coals in a}cavity presenting about 4 feet}25surface of tube}Supply of coal for 1 hour6Water for ditto, allowing steam}of one atmosphere to be 1/1800}32the specific gravity of water}163It may at first view appear superfluous to inquire further relative to a first mover for aërial navigation; but lightness is of so much value in this instance, that it is proper to notice the probability that exists of using the expansion of air by the sudden combustion of inflammable powders or fluids with great advantage. The French have experimentally shown the great power produced by igniting inflammable fluids in close vessels; and several years ago, an engine was made in this country to work in a similar manner, by the inflammation of spirit of tar.It appears that eighty drops of this fluid raised eight hundred weight to the height of 22 inches; hence a one-horse power may consume from 10 to 12 pounds per hour, and the engine itself need not exceed 50 pounds weight.Probably a much cheaper engine of this sort might be produced by gas-light apparatus, and by firing the inflammable air generated, with adue portion of common air, under a piston. Upon some of these principles it is perfectly clear that force can be obtained by a much lighter apparatus than the muscles of animals or birds, and therefore in such proportion may aërial vehicles be loaded with inactive matter. Even the high pressure steam-engine doing the work of six men, and only weighing equal to one, will readily raise five men into the air, but by increasing the magnitude of the engine ten, fifty; or even five hundred men may equally well be conveyed.Having rendered the accomplishment of this object probable upon the general view of the subject, it will now be necessary to point out the principles of the art itself. The whole problem is confined within these limits, viz. To make a surface support a given weight by the application of power to the resistance of the surrounding atmosphere.Many experiments have been made upon the direct resistance of air by Mr. Robins, Mr. Rouse, Mr. Edgeworth, Mr. Smeaton, and others. The result of Mr. Smeaton's experiments and observations was, that a surface of one square foot met with a resistance of one pound, when it travelled perpendicularly to itself through air at a velocity of 21 feet per second.Having ascertained this point, had our tables of angular resistance been complete, the size of the surface necessary for any given weight would easily have been determined. Theory, which gives the resistance of a surface opposed to the same current in different angles, to be as the squares of the sine of the angle of incidence, isof no use in this case; as it appears, from the experiments of the French Academy, that in acute angles, the resistance varies much more nearly to the direct ratio of the sines, than as the squares of the sines of the angles of incidence. The flight of birds will prove to an attentive observer, that, with a concave wing apparently parallel to the horizontal path of the bird, the same support, and of course resistance, is obtained. And hence it appears that, under extremely acute angles with concave surfaces, the resistance is nearly similar in them all.Six degrees was the most acute angle, the resistance of which was determined by the valuable experiments of the French Academy; and it gave 4/10 of the resistance, which the same surface would have received from the same current when perpendicular to itself. Hence then a superficial foot, forming an angle of six degrees with the horizon, would, if carried forward horizontally (as a bird in the act of skimming) with a velocity of 23·6 feet per second, receive a pressure of 4/10 of a pound perpendicular to itself. And if we allow the resistance to increase as the square of the velocity, at 27·3 feet per second it would receive a pressure of one pound.The flight of thecorvus frugilegus, or rook, during any part of which it can skim at pleasure, is (from an average of many observations) about 34·5 feet per second. The concavity of the wing may account for the greater resistance here received, than the experiments upon plain surfaces would indicate.The angle made use of in the crow's wing ismuch more acute than six degrees: but in the observations that will be grounded upon these data, it may safely be stated that every foot of such curved surface, as will be used in aërial navigation, will receive a resistance of one pound, perpendicular to itself, when carried through the air in an angle of six degrees with the line of its path, at a velocity of about 34 or 35 feet per second.The next object is to apply what has been advanced to the theory of aërial navigation; and the following description will convey a just idea of the best method of effecting it. Suppose a sail to be made of thin cloth, of a firm texture, containing two hundred square feet; and that the weight of the man and the apparatus is 200 pounds. Then if the wind blow with a velocity of 35 feet per second, in a certain direction, at the same time that a cord in that direction sustains a tension of 21 lbs. from being fixed to the machine, the whole apparatus will be suspended in the air. But it is perfectly indifferent whether the wind blow against the plane, or the plane be propelled by any means against the air with an unequal velocity. Hence, if this machine were drawn forward by the cord under a tension of 21 lbs. and with a velocity of 35 feet per second, the whole would be suspended in an horizontal path. Now, if, instead of this cord, any other propelling power were generated in the same direction, and with the same intensity, an equivalent effect would be produced, and aërial navigation accomplished.Vide Bishop Wilkins's Math. Magic.—Hook's Philosophical Collections.—Sir G. Cayley on Aërial Navigation.

Bacon, and an Italian priest named Francisco Lana, endeavoured to accomplish it by means of two thin hollow globes, exhausted of air, which being considerably lighter than that fluid, were intended to sustain a chair suspended to their lower extremity, and on which the aeronaut might be seated. But Dr. Hook, in a work published some time after theProdromoof Lana, plainly showed the fallacy of the attempt, though without in the least attempting to deny the possibility of eventually effecting this object.

Bishop Wilkins, who was also a disciple of the flying system, describes a species of land-sailing vessels or chariots, which were then commonly used in China: and it is rather a curious fact that a German Count, possessing as much of modesty as the generality of foreign mechanics, has lately given to the public, as his own, an invention which has been known in Europe, and occasionally employed in Asia, for the last four hundred years.

But of all the plans that have hitherto been devised, those only which have mechanic power as their basis appear to have any chance of success. This may be considered as an unerringdatumto guide the future experimentalist, the certainty of which is fully demonstrated by a comparison ofthe powers of the human frame with those of the feathered tribe: for it has been calculated by an ingenious anatomist, that the muscles which move the wings downwards in a bird in many instances, constitute not less than the sixth part of the weight of the whole body; while those of a man are not one hundredth part so large. By the use of springs, however, wound to a certain degree of tension, prior to embarking upon the intended expedition, and acting upon cranks working the wings, the same power as that possessed by the feathered race may be obtained, and the springs may be readily made to draw more than fifty times their weight. By this means a whalebone, or other light carriage, may be raised, though it would be but for a short time, as it would not be in the power of the aëronaut to wind the springs so quick as the machine would require.

From this, then, it will be seen that, to produce the effect necessary for this species of navigation, it is only requisite to have a first mover, which will produce more power, in a given time, in proportion to its weight, than the animal system of muscles.

High pressure steam-engines have been made to operate by expansion only, and they, it appears, might be constructed so as to be light enough for this purpose. In that case, however, it will be evident that the usual plan of a large boiler must be given up, and the principle of injecting a proper charge of water into a series of tubes, forming the cavity of the fire, must be adopted in lieu of it.

The following estimate will show the probableweight of such an engine with its charge for one hour.

lbs.The engine itself, from 90 to100Weight of inflamed coals in a}cavity presenting about 4 feet}25surface of tube}Supply of coal for 1 hour6Water for ditto, allowing steam}of one atmosphere to be 1/1800}32the specific gravity of water}163

It may at first view appear superfluous to inquire further relative to a first mover for aërial navigation; but lightness is of so much value in this instance, that it is proper to notice the probability that exists of using the expansion of air by the sudden combustion of inflammable powders or fluids with great advantage. The French have experimentally shown the great power produced by igniting inflammable fluids in close vessels; and several years ago, an engine was made in this country to work in a similar manner, by the inflammation of spirit of tar.

It appears that eighty drops of this fluid raised eight hundred weight to the height of 22 inches; hence a one-horse power may consume from 10 to 12 pounds per hour, and the engine itself need not exceed 50 pounds weight.

Probably a much cheaper engine of this sort might be produced by gas-light apparatus, and by firing the inflammable air generated, with adue portion of common air, under a piston. Upon some of these principles it is perfectly clear that force can be obtained by a much lighter apparatus than the muscles of animals or birds, and therefore in such proportion may aërial vehicles be loaded with inactive matter. Even the high pressure steam-engine doing the work of six men, and only weighing equal to one, will readily raise five men into the air, but by increasing the magnitude of the engine ten, fifty; or even five hundred men may equally well be conveyed.

Having rendered the accomplishment of this object probable upon the general view of the subject, it will now be necessary to point out the principles of the art itself. The whole problem is confined within these limits, viz. To make a surface support a given weight by the application of power to the resistance of the surrounding atmosphere.

Many experiments have been made upon the direct resistance of air by Mr. Robins, Mr. Rouse, Mr. Edgeworth, Mr. Smeaton, and others. The result of Mr. Smeaton's experiments and observations was, that a surface of one square foot met with a resistance of one pound, when it travelled perpendicularly to itself through air at a velocity of 21 feet per second.

Having ascertained this point, had our tables of angular resistance been complete, the size of the surface necessary for any given weight would easily have been determined. Theory, which gives the resistance of a surface opposed to the same current in different angles, to be as the squares of the sine of the angle of incidence, isof no use in this case; as it appears, from the experiments of the French Academy, that in acute angles, the resistance varies much more nearly to the direct ratio of the sines, than as the squares of the sines of the angles of incidence. The flight of birds will prove to an attentive observer, that, with a concave wing apparently parallel to the horizontal path of the bird, the same support, and of course resistance, is obtained. And hence it appears that, under extremely acute angles with concave surfaces, the resistance is nearly similar in them all.

Six degrees was the most acute angle, the resistance of which was determined by the valuable experiments of the French Academy; and it gave 4/10 of the resistance, which the same surface would have received from the same current when perpendicular to itself. Hence then a superficial foot, forming an angle of six degrees with the horizon, would, if carried forward horizontally (as a bird in the act of skimming) with a velocity of 23·6 feet per second, receive a pressure of 4/10 of a pound perpendicular to itself. And if we allow the resistance to increase as the square of the velocity, at 27·3 feet per second it would receive a pressure of one pound.

The flight of thecorvus frugilegus, or rook, during any part of which it can skim at pleasure, is (from an average of many observations) about 34·5 feet per second. The concavity of the wing may account for the greater resistance here received, than the experiments upon plain surfaces would indicate.

The angle made use of in the crow's wing ismuch more acute than six degrees: but in the observations that will be grounded upon these data, it may safely be stated that every foot of such curved surface, as will be used in aërial navigation, will receive a resistance of one pound, perpendicular to itself, when carried through the air in an angle of six degrees with the line of its path, at a velocity of about 34 or 35 feet per second.

The next object is to apply what has been advanced to the theory of aërial navigation; and the following description will convey a just idea of the best method of effecting it. Suppose a sail to be made of thin cloth, of a firm texture, containing two hundred square feet; and that the weight of the man and the apparatus is 200 pounds. Then if the wind blow with a velocity of 35 feet per second, in a certain direction, at the same time that a cord in that direction sustains a tension of 21 lbs. from being fixed to the machine, the whole apparatus will be suspended in the air. But it is perfectly indifferent whether the wind blow against the plane, or the plane be propelled by any means against the air with an unequal velocity. Hence, if this machine were drawn forward by the cord under a tension of 21 lbs. and with a velocity of 35 feet per second, the whole would be suspended in an horizontal path. Now, if, instead of this cord, any other propelling power were generated in the same direction, and with the same intensity, an equivalent effect would be produced, and aërial navigation accomplished.Vide Bishop Wilkins's Math. Magic.—Hook's Philosophical Collections.—Sir G. Cayley on Aërial Navigation.

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