8,080 × 95=14,544 × 87100=12,653units in carbon.34,662 × 95=62,391 × 5100=3,11915,772units in hydrogen.units in coal.
15,772 × 7722= 12,175,984 foot pounds of energy is occluded in the static caloric contained in one pound of such coal.
A horse-power is estimated as capable of raising 33,000 pounds one foot high per minute, and for this reason it is termed 33,000 foot pounds per minute. So we have 33,000 × 60 = 1,980,000 foot pounds per hour, as a horse-power.
The best class ofcompound condensingengines,3with all the modern improvements, require 1.828 pounds of coal per 1 h.p. per hour. Thus we have—
12,175,984 × 1.82822,257,699Foot pounds in one h.p.1,980,000Foot pounds lost per h.p.20,277,699Per cent utilized per h.p.8.94Per cent lost per h.p.91.06100.00
In the ordinary practice of stationary non-condensing engines, from three to four pounds of coal are required per horse-power per hour. Now, taking the best of this class at 3 pounds, we have—
12,175,984 × 3 =36,527,952One h.p.1,980,000Loss per h.p.34,547,952Per cent utilized per h.p.5.42Per cent lost per h.p94.58100.00
From these facts it may be assumed that after making due allowance for variable qualities of the coal, the steam engine process, as at present practiced, will not utilize more than from 5 to 10 per cent. of the energy contained in the fuel used. It will thus be seen that the process of converting static to dynamic caloric by luminous combustion, by means of the steam engine, is an exceedingly wasteful and costly method, and leaves much room for economy.
Taking an ordinary grade of petroleum as consisting of 13 per cent. hydrogen, 78 carbon, 6 oxygen, 3 nitrogen and ash, we have as its energy in foot pounds per pound of oil—
62,391 × 13100= 8,110 H.}19,454 units.14,544 × 78100= 11,344 C.
19,454 × 772 = 15,018,488 foot pounds. Thus, while our best coal contains twelve million, the petroleum contains fifteen million foot pounds of occluded energy in each pound, which is equal to 118,000,000 foot pounds, or 60 horse power for one hour, from one gallon of such oil.
At present electricity is generated by two methods, and both of these aresecond powers. Metals are smelted by luminous combustion as a first power, and then oxidized by non-luminous combustion as asecond power, and coal is consumed by luminous combustion, by which steam is generated as a first power, to drive a dynamo-generator whereby electricity is obtained as asecond power. Now, of the two methods, the latter is much the cheaper, and as I have shown that the best compound condensing engines only utilize 8.94, and a fair average single cylinder condensing engine only utilizes 5.42 per cent. of the energy of the fuel consumed, and as at the best not over 70 per cent. of the foot pounds obtained from the engine can be utilized as electricity, from which we must deduct loss by friction, etc., it will be readily seen that not more than 5 per cent. of the energy of the fuel can be developed by the dynamo-generator as electricity by the present method.
The great want of the present age is a process by which the static caloric of carbon or a hydrocarbon maybe set free by non-luminous combustion; or, in other words, a process by which coal or oil may be oxidized at a low degree, within an insulated vessel; if this can be accomplished (and I can see no reason why we should not look for such invention), we would be able to produce from twelve to fifteen million foot pounds of energy (electricity) from one pound of petroleum, or from ten to twelve million foot pounds from one pound of good coal, which would be a saving of from 90 to 95 per cent. of present cost, and leave the steam engine for historical remembrance.
Electricity may be generated by water or wind power to great advantage, and conveyed to a distance for motive power. The practicability of generating electricity at Niagara by which to propel trains to New York and return may be considered almost settled; and I conceive a second invention of importance which is now needed is an apparatus by which the rising and falling tides may be utilized for driving dynamo machines, by which electricity may be generated for lighting the coast cities, and it is not unreasonable to expect that such an apparatus will soon be provided; and in such an event gas companies would suffer.
It is a well known fact among electricians that the volume and tension of electricity vary both in the earth and in the atmosphere at different sections of the earth's surface, and I conceive that we may yet find means of utilizing this differential tension of electricity; indeed, it is reported that during a recent storm the wires of an ocean cable were grounded at both ends and a sufficient current for all practical purpose flowed from the European to the American continent, with all batteries removed, showing that the tension was so much greater in Europe as to cause the electricity to flow through the copper cable to this side in preference to passing through the earth or the sea. It is also said that during an east-going storm it was found impossible to work the telegraph lines between New York and Buffalo, but on taking off the batteries at both ends and looping the ends of the wire in the air, that a constant current of electricity passed from Buffalo to New York, and the line was kept in constant use in that direction without any battery connection until the storm abated. Now, how far or to what advantage we may be able to utilize this differential tension of electricity in the earth and the air, we cannot now say; but I think that we may justly look for valuable developments in this direction.
If, as I verily believe, a process will soon be discovered by which dynamic caloric can be produced by the oxidation of petroleum with non-luminous combustion in an insulated chamber, as we now oxidize zinc, electricity will then be obtained from so small a weight, and at such a low cost, as to insure aerial navigation beyond a doubt. Not with balloons and their cumbrous inflations, but with machines capable of carrying the load, and traveling by displacement of the air at high velocities. Therefore we may expect that aerial navigation will be developed in the near future to be one of the greatest enterprises of the world.
And lastly, will it pay to use luminous combustion as a first power for generating dynamic caloric for use as a second power, as is now practiced?
At the University of Pennsylvania, in Philadelphia, gas is consumed in an Otto gas engine, which drives a Gramme generator; and the lecture room is lighted with electricity, and I am informed that the light is both betterand cheaperthan when they used the gas in the ordinary gas burners. Hence we may expect to see gas consumed to advantage for producing electric lights.
Considering the difficulties of transmitting steam power to a considerable distance, and the comparative great cost of running small engines, it is more than likely that electricity as at present generated will be found to be economical for driving small motors.
Having thus endeavored to explain what electricity is, and the laws which govern the occlusion of static caloric, and the development of dynamic caloric (electricity), in conclusion I call the attention of the inventors of the age to the great need of a process for oxidizing coal or oil at a low degree, within an insulated vessel. With such an invention electricity would be obtained at such a low cost that it would be used exclusively to light and heat our houses, to smelt, refine, and manipulate our metals, to propel our cars, wagons, carriages, and ships, cook our food, and drive all machinery requiring motive power.
[1]
A paper read before the Engineers' Society of Western Pennsylvania, Nov. 15, 1881.
A paper read before the Engineers' Society of Western Pennsylvania, Nov. 15, 1881.
[2]
Dr. Joule—foot pounds in one unit.
Dr. Joule—foot pounds in one unit.
[3]
"American Engineer," Vol. II., No. 10, page 182.
"American Engineer," Vol. II., No. 10, page 182.
For some time past it has been the desire of many photographers to have at hand a ready means of producing a powerful and highly actinic artificial light, suitable for the production of negatives, and easily controllable. Several forms of apparatus have been designed, and I believe have been, to a certain extent, employed successfully in portraiture. But it has been well known for many years that the electric light was just the light that would answer the photographer's requirements, owing to its possessing great actinic power; but the cost of its production was too great for general adoption; indeed, such might be said of it now as far as dynamo-electric machines and steam or gas motors are concerned, for the majority of photographers. It is true that several influential photographers have already adopted the use of the electric light for portraiture, but the primary cost of the apparatus employed by these firms is far beyond the reach of most portraitists. The apparatus about to be described is one that has been carefully worked out to meet the wants of the photographer in almost every particular; in fact, with this apparatus, portraits can, and have been, produced in an ordinary sitting room, as good and as perfect as if taken in a well-lighted studio.
Fig.1.
The generator of the electric current consists of a series of voltaic elements of zinc and carbon—forty-eight in number—these elements being made up of ninety-six zinc plates and forty-eight carbon plates; thus the generator consists of forty-eight voltaic elements arranged in rows of twelve; they are all carefully screwed upon suitable bars of wood, and these bars are joined by other cross bars, which bind the whole in a compact form; the battery being suitably connected so as to produce a current of very high electro-motive force, and so arranged over their exciting trough that the plates can be raised or lowered at will, as seen in Fig. 1, which will explain itself almost at first sight.
The troughs are made of mahogany, put together with brass screws, and well saturated with an insulating compound which also makes them acid proof; the cells are charged with a saturated solution of bichromate of potash, to which has been added twenty fluid ounces of sulphuric acid to each gallon.
Fig.2.
To produce the electric current, all that is needed is to lower these suspended elements down into the trough, having previously connected the wires as shown in Fig. 1, to the electric lamp, Fig 2. At once a light starts up, between the carbon pencils, of a thousand-candle power or more. With a light of this power, a large head on cabinet or carte size plate may be produced in three or four seconds.
The generator occupies a floor space of three feet six inches by two feet, and stands two feet six inches high. The cells will cost 5s. to charge, and will produce upward of sixty negatives before being exhausted. All that is necessary, in recharging, is to lift the elements up out of the way, take out the troughs by their handles and empty them, charging them again by means of a toilet jug. When replaced, the whole apparatus is fit for use again; the whole of the above operation occupies but a quarter of an hour, and as there are no earthenware cells employed, there is no fear of breakage.
The small amount of labor and cost of working the above apparatus will compare favorably with the production of the electric light from a dynamo-electric machine for the photographer, and when we consider that the cost of the whole of the above apparatus, consisting of a generator automatic lamp, reflector, and all the necessary appendages, is less then one-tenth of the dynamo machine, motor, shafting, etc., to produce the same result, it would seem to have a greater claim for its adoption with those who wish to employ the electric light, whether for work at night, use in the sitting room, or to assist daylight on the dark and foggy days of winter.
Fig. 2 shows the arrangement of the electric lamp. A is the automatic regulator; B, the reflector; C, top extension of the reflector; D, small tissue paper screen to prevent the intense arc-rays from coming in contact with the sitter; E, stand with sliding rod. This appendage can be wheeled about with ease, as it is arranged to run upon four casters.
When the generator is in use it may be placed within easy reach of the operator, so that the exposure may be made by lowering the elements in their troughs just for the requisite time, and withdrawing immediately the exposure is made; there is no need to fear any inconvenience from deleterious fumes as none are given off, so it may be used in any studio or sitting-room without any inconvenience from this source, and as far as many trials have gone, it seems to meet every requirement demanded by the photographer for the production of portraits by means of the electric light.—Photo. News.
ELECTRIC LIGHTER.
The little apparatus shown in the accompanying cut will certainly find favor with smokers, as well as with persons generally who often have need of a fire or light. It forms one of the most direct applications of dry piles of all the systems on the Desruelles plan. Instead of filling piles with a liquid, this plan contemplates the introduction into them of a sort of asbestos sponge saturated with an acid or any suitable solution. In this way there is obtained the advantage of having a pile which is in some sortdry, that may be moved, shaken, or upset without any outflow of liquid, and which will prove of special value when applied to movable apparatus, such as portable lighters, alarms on ships, railroads, etc. It is hardly necessary to say that while the introduction of this inert substance diminishes the volume of the liquid, the electro-motive force of the pile is thereby in nowise affected, but its internal resistance is increased. This, however, is of no consequence in the application under consideration. The lighter consists of a small, round, wooden box containing the pile, and surmounted by a spirit lamp. A platinum spiral opposite the wick serves for producing the light. The pile is a bichromate of potash element, in which there is substituted for the liquid a solution of bichromate identical with that used in bottle piles. The zinc is suspended from a small lever, in which it is only necessary to press slightly to bring the former in contact with the asbestos paste, when, the zinc being attached, a current is set up which traverses the spiral, heats it to redness, and lights the spirit. The pile, when once charged, may be used for several hundred lightings. When the spiral no longer becomes red hot, it is only necessary to replace the paste—an operation of extreme simplicity. When the pressure is removed from the little lever, the zinc, being raised, is no longer acted upon by the liquid with which the asbestos is saturated. Mr Desruelles is constructing upon the same principle a gas lighter, the pile of which is fixed at the extremity of a handle whose length varies with the height of the gas burners to be reached. These little domestic apparatus are being exhibited at the Paris Electrical Exhibition.
TheEvening Bulletinof the 29th October has the following:
This afternoon a series of experiments were conducted at the Public Buildings which will be of great interest to electricians all over the country, and upon which the success of a number of underground telegraph projects in different parts of the United States depends. In all projects of this kind the problem which has given most trouble to inventors has been to overcome the induction. In other words, electric currents will leave their original conductors and pass to other conductors which may be near at hand. This interchange of currents may take place without seriously hindering ordinary telegraphy, as the indicators are not delicate enough to detect the induction. When telephones came into use, however, the induction became a great source of trouble to electricians, it often being the case that the sounds and influences from without were sufficient to drown out sounds in a telephone. To-day's experiment was conducted by Mr. J.F. Shorey, a well-known electrician, who exhibited Dr. Orazio Lugo's cables for electric light, telephone, and telegraphic purposes.
A large number of prominent electricians were present, including the following: General J.H. Wilson, President of the N.Y. and N.E. Railroad, of Boston; Messrs. Frank L Pope, S.L.M Barlow, George B. Post, Charles G. Francklyn, Col. J.F. Casey, W.H. Bradford, and Selim R. Grant, of New York; James Gamble, General Manager of the Mutual Union Telegraph Co.; T.E. Cornich and W.D. Sargent, of the Bell Telegraph Co.; S.S. Garwood and J.E. Zeublen, of the Western Union, and others.
The principal tests were made through the conduits on Market Street, laid by the National Underground Electric Company as far as Ninth Street. A cable of five conductors was laid through the conduit. Two of these conductors consisted of simple "circuit wires," while the other three were what is known as "solenoids." A solenoid wire is a single straight wire, connected at each end with and wound closely around by another insulated wire, this forming a complete system, the electric currents returning into themselves. Electricians claim that the solenoid effectually overcomes all induction, and this afternoon experiments were made for the purpose of proving that assertion. In the telephones, connected by the ordinary wires, a constant burr and click could be heard, that sound being the induction from the wires on the poles on Market Street, sixty feet overhead. With the solenoid the only sound in the telephones was the voices of the persons speaking. The faintest whispers could be heard distinctly, and the ease and comfort of conversation was in marked contrast to the other telephone on the ground wires. A set of telegraph indicators was also attached to the wires in use in the cable. The sounds were transferred from one "ground wire" to the other, while the solenoids seemed to resist every influence but that directed upon them by the operators. Another interesting test was made. The electric current for a Hauckhousen lamp was passed through a long coil of solenoid wire. Separated from this coil by a single newspaper, lay a coil of wire attached to telephones, yet not a sound could be heard in the telephones but the voices of the persons using them. The current of electricity created by a dynamo-electric machine is of necessity a violent one, and in the use of ordinary wires the induction would be so great that no other sounds could possibly be heard in the telephones.
In an article by Count du Moncel, published inScientific American Supplement, No 274, page 4364, the author, after describing Dr. Herz's telephonic systems, deferred to another occasion the description of a still newer system of the same inventor, because at that time it had not been protected by patent. In the current number ofLa Lumière Electrique, Count Moncel returns to the subject to explain the principles of these new apparatus of Dr. Herz, and says:
I will first recall the fact that Dr. Herz's first system was based upon the ingenious use (then new) of derivations. The microphone transmitter was placed on a derivation from the current going to the earth, taken in on leaving the pile, and the different contacts of the microphone were themselves connected directly and individually with the different elements of the pile. The telephone receiver was located at the other end of the line, and when this receiver was a condenser its armatures were, as a consequence of this arrangement, continuously and preventively polarized, thus making it capable of reproducing conversation.
DR. HERZ'S TELEPHONIC SYSTEMS.
This arrangement evidently presented its advantages; but it likewise possessed its inconveniences, one of the most important of these being the necessity of employing rather strong piles and consequently of exposing the line to those effects of charge which react in so troublesome a manner in electrical transmissions when they occur on somewhat lengthy lines. Now the fact should be recalled that Dr. Herz's principal object was the application of the telephone to long lines, and he has been applying himself to this problem ever since. He at first thought of employing reversed currents, as in telegraphy; but how was such a result to be attained with systems based upon the use of sonorously-vibrating transmitters? He might have been able to solve the problem with the secondary currents of an induction bobbin, as Messrs. Gray, Edison, and others had done; but then he would no longer have been benefited by those amplifications which are furnished by the variations of pressure-derivations in microphones, and this led him to endeavor to increase the effects of the induced currents themselves by prolonging their duration, or rather by combining them in such a way that they should succeed each other, two by two, in the same direction; and this is the way he solved the problem in the beginning.
The fact should also be recalled that Dr. Herz had, from his first experiments, recognized the efficiency of those microphonic contacts that are obtained by the superposition of carbon disks or other semi-conducting substances. He has employed these under different arrangements and with very diverse groupings, but, as a general thing, it has been the horizontal arrangement which has given him the best effects.
Let us suppose, then, that four systems of contacts of this nature are arranged at the four corners of an ebonite plate, C C (Figs. 1 and 2), at A, A¹, B, B¹, and that they are connected with each other, as shown in the cuts—that is to say, the upper disks,e,f,g,h, parallel with the sides of the plate, and the lower disks, A, A¹, B, B¹, diagonally. Let us admit, further, that the plate pivots about an axis, R; that the disks are traversed by small pins fixed in the plate; and that small leaden disks rest upon the upper disks. Finally, let us imagine that the plate is connected at one end, through a rod T, with a telephone diaphragm. Now it will be readily understood that the vibrations produced by the diaphragm will cause the oscillation of the plate, C C, and that there will result therefrom, on the part of the disks, two effects that will succeed one another. The first will be, for the ascending vibrations, an increase of pressure effected between the disks of the left side, by reason of their force of inertia being increased by that of the lead disks; and the second will be, for the disks to the right, and, for the same reason, a reduction of pressure which will take place through resilience, at the moment of change in direction of the vibrating motions.
If the current from a pile, P, traverses all these disks, through the connections that we have just mentioned, and passes through the primary helix (through the wire, I) of an induction coil H H' (Fig. 2), located beneath the apparatus, and if the secondary current from this bobbin corresponds, through the wire I, with a telephone line in which there is interposed a telephone or a speaking condenser, there will be set up an inverse induced current, which, being reversed as a consequence of the crosswise connections of the disks, will continue the action of the first or increase its duration, and, consequently, its force, through the telephone receiver.
The results of this system are very good; but Dr. Herz has endeavored to simplify it still further, and with this object in view has experimented on several arrangements. For example, to obtain inversion a contact was simply placed on each side of the vibrating plate. Although the movements of this latter are not, as we know, of the nature of ordinary sonorous vibrations, it was thought that they might prove to be in opposite directions on the two sides of the plate, and that one of the contacts might be compressed while the other was free. So notwithstanding the advantages of this arrangement, it was thought necessary to place the plate vertically in order to give the same regulation to the two contacts which it is essential should be identical. But it became difficult to regulate by weight; and even to succeed in regulating at all, it became necessary to employ two parallel diaphragms, vibrating in unison, and each carrying its contact, but in opposite directions. Afterwards, the horizontal arrangement was again adopted; but, by a clever combination, the two principles applied by Dr. Herz—derivation and inversion—were united. The current is then led to a double contact, where it divides. This contact is arranged under the plate in such a way that its two points of variable resistance act in opposite directions to each other, or, in some apparatus, so that one of the points has no variation, while the other is in action. The result that occurs may be easily imagined. The system has been experimented with under different forms; in one case the derivation is simple, that is, a single one of the currents being sent into the line, while in another case it is double, each of the branches being provided with a bobbin and communicating with the receiver. In the latter case the result is remarkably good, but the apparatus is not free from a certain amount of complication, and demands, moreover, particular care in its construction, experience having shown that the induction coils must not be equal, but that they must present resistances combined according to the circuit doing duty. It should be added that researches have been continued as to the bodies proper to be employed as microphonic contact, with the result of bringing out the important fact that the number of substances that can be put to this use is almost unlimited. The contacts of the Herz apparatus are now being made of conducting bodies (metals for example) reduced to powder and conglomerated by chemical means with a sort of non-conductive cement. The proportion of the elements depends upon the conductivity of the materials employed, and it alone determines the microphonic value of the compound, the nature of the elements apparently having scarcely any influence.
Nor has the speaking condenser been neglected. As regards this, efforts have seemingly been made toward finding a convenient arrangement and a regular mode of construction, the good working of these apparatus being absolutely dependent upon the care with which they are set up.
In Dr. Herz's opinion, the telephone is not to remain a single apparatus, varied only as to form, but, on the contrary, must be actually modified according to the purposes for which it is designed. He thinks that a telephone operating at great distances must differ from a city apparatus, and that an instrument for transmitting song can not be absolutely the same as one for conversational purposes. So he has endeavored to create types that shall prove appropriate for these different applications.
For these measures there are adopted the fundamental unities—centimeter, gramme, second, and this system is briefly designated by the letters C., G., S. The practical units, theohmand thevolt, will retain their present definitions; the ohm is a resistance equal to 109absolute unities (C., G., S.), and the volt is an electromotive force equal to 108absolute unities (C., G., S.). The practical unit of resistance (ohm) will be represented by a column of mercury of 1 square mm. in section at the temperature of 0°C. An international commission will be charged with ascertaining for practice, by means of new experiments, the height of this column of mercury representing the ohm. The nameampèrewill be given to the current produced by the electromotor force of 1 volt in a circuit whose resistance is 1 ohm.Coulombis the quantity of electricity defined by the condition that in the current of an ampère the section of the conductor is traversed by a coulomb per second.Faradis the capacity defined by the condition that a coulomb in a condenser, whose capacity is a farad, establishes a difference of potential of a volt between the armatures.
In order to accumulate electricity for the production of light or motive power, the author has arranged secondary batteries, which differ from those of M.G. Planté. At the negative pole he uses a sheet of palladium, which, during the electrolysis, absorbs more than 900 times its volume of hydrogen. At the positive pole he uses a sheet of lead. The electrolyzed liquid is sulphuric acid at one tenth. This element is very powerful, even when of small dimensions. Another secondary element which has also given good results, is formed at the negative pole of a slender plate of sheet-iron. This plate absorbs more than 200 times its volume of hydrogen when electrolyzed in a solution of ammonium sulphate. The positive pole is formed of a plate of lead, pure or covered with a stratum of litharge, or pure oxide, or all these substances mixed. These metallic plates are immersed in a solution containing 50 per cent. of ammonium sulphate. Another arrangement is at the negative pole, sheet-iron; at the positive pole a cylinder of ferro-manganese. The electrolyzed liquid contains 40 per cent. ammonium sulphate.
Though known from remote times, the date of the first opening of the famous mines of quicksilver of Almadén has not been precisely determined. Almost all the writers on the subject agree that cinnabar, from Spain, was already known in the times of Theophrastus, three hundred years before the Christian era, although there is evidence in the writings of Vitruvius that they were worked at a still earlier date, Spanish ore being sent to Rome for the manufacture of vermilion. Such ore constituted a part of the tribute which Spain paid to Rome emperors, and there are records of its receipt until the first century after Christ. The history of Almaden during the reign of the Moors is so much involved in doubt that some writers deny altogether that the Arabs worked the deposit; still the very name it now bears, which means "the mine," and many of the technical terms still in use, give evidence that they knew and worked that famous deposit. As for their Christian conquerors, there are stray indications that they extracted mercury during the twelfth and thirteen centuries. In 1417, Almaden was given the privileges of a city, and from 1525 to 1645 the working of mines was contracted for by the wealthy family of Fugger, of Augsburg, Germany. Since then, the mine has been worked by the state, though the Rothschilds have controlled the sale of the product.
According to Vitruvius, the works for manufacturing vermilion from Spanish ore in Rome were situated between the temple of Flora and Quirino. The ore was dried and treated in furnaces, to remove the native mercury it contained, and was then ground in iron mortars and washed. In addition, small quantities of quicksilver and vermilion were made at Almaden. The ancients describe other methods, among which Theophrastus speaks of using vinegar, which, however, appears from modern investigations to have been an erroneous account. Nothing definite is known concerning the methods of the Moors; we possess only as a proof that they produced mercury, an account of a quicksilver fountain in the marvelous palace of Abderrahman III., at Medina-Zahara, and the works of Rasis, an Arab. The Moors probably extracted mercury at Almaden, from the eighth to the twelfth century, by the use of furnaces called "xabecas," which latter, in the fourteenth century, were still employed by the Christians, who continued them till the seventeenth century, when German workmen replaced them by "reverberatory" furnaces, which in turn were superseded in 1646 by aludel or Bustamente furnaces. There is an anonymous description of the working with xabecas as practiced at Almaden in 1543, and later accounts in 1557 and 1565. The ore was put into egg-shaped vessels with a lid, the mineral being covered over with ashes. The vessels were packed in a furnace heated with wood, about 60 pounds being used per pound of quicksilver made. This system was also applied at the Guancavelica mines, discovered in Peru in 1566, where the xabecas were abandoned in 1633, being replaced by the furnaces invented by Lope Saavedra Barba, which there were called "busconiles," while in Spain they were named Bustamente furnaces, and elsewhere aludel furnaces. They were introduced at Almaden thirteen years after their first use in Peru by Juan Alfonso de Bustamente, Barba and his son having been lost at sea on their way to the Peninsula. In 1876, there were at Almaden, at the works at Buitrones, twenty such aludel furnaces and two Idria furnaces. D. Luis de la Escosura y Morrogh, from whose work we take the above notes, has followed the historical details of the growth of Almaden closely, and from his account of the method of working in 1878 we take some data:
It is not an easy matter to explain the classification of the ore at Almaden.Metalis there called the richest mineral, composed of quartz impregnated with crystalline cinnabar.Requiebroare middlings of medium richness,Chinaare smalls, andVaciscosthe finest ore. Besides native mercury, which the ores of Almaden contain in greater or smaller quantity, the most abundant mineral is cinnabar, which is always crystalline and is often crystallized. The ores have, besides, a small quantity of selenium and iron pyrites intimately mixed with the cinnabar. The gangue is quartz, occasionally argillaceous and bituminous. The following are assays of some of the ores made by Escosura:
Metal.Requiebro.Vaciscos.China.12345678Cinnabar29.121.213.310.25.12.81.20.86Iron pyrites.2.22.02.01.912.31.52.12.80Bituminous matter0.61.01.01.24.60.73.40.90Gangue67.574.882.176.577.593.390.293.50————————————————Total99.494.098.898.999.598.398.798.06Quicksilver25.0518.2811.478.644.402.411.030.75
It appears to be a difficult matter to determine the average percentage of the various grades of ore. In 1872, a commission classified and sampled a lot of 300 tons with the following results:
Grade.No.Quantity,kilos.Per cent.mercury.Averageof grade.Metal1.2.81,89014,97023.8622.6524.80Requiebro3.4.12,24017,00015.2010.5012.47China5.6.7.31,89032,36028,9603.841.170.101.75Vaciscos8.78,3209.249.24
This general average of 12.28 per cent. of mercury is pronounced higher than the usual run of the ore, which, it is stated, does not go above 7 to 8.50 per cent.
The furnace in which the ore is treated is cylindrical, 2 meters in diameter, and 3.70 meters high from a brick grate, supported by three arches to the arched roof. At the level of the grate is a charging orifice, and near the roof are openings into two chambers, from the bottom of which extend 12 lines of aludels, clay vessels, open at both ends, the middle being expanded. The mouth of one fits into the back end of the one following, a channel being thus formed through which the fumes to be condensed are passed. The lines of aludels which are laid on the ground terminate in a chamber, and for half the distance between the furnaces and these chambers the ground slopes downward, while for the other it slopes upward. Two furnaces are always placed side by side, and the pair have from 1,100 to 1,150 aludels.
The operation is as follows: A layer of poor quartz is spread over the brick grate; this is followed by a layer of smalls, and then by a layer of still finer stuff, all of it being low grade ore. On top of this are piled two-thirds of thechinaof the charge on which themetalis put. Then follows a layer ofrequiebro, another lot ofchina, and finally thevaciscos, shaped into balls, the whole charge amounting to about 11½ tons, which is put in from an hour and a half to two hours by three men. The charging orifice is then closed, the aludels are luted, and everything made tight. The fires under the brick grate are lighted and kept going for twelve hours, during which time furnaces, charge, and condensing apparatus are heated up. During this period, the temperature in the condensing-chamber at the end of the line of aludels runs up 40 or 50 degrees Celsius, and some mercury, evidently part of the native quicksilver, is noticed in it.
The temperature of the aludels in the immediate vicinity of the furnaces is about 140 degrees C. During this period, the consumption of fuel is four parts to every part of quicksilver produced. At its close, the fire is drawn, and the second period begins. The air entering through the brick arch is heated to from 200 to 300 degrees by contact with the layer of poor stuff, the cinnabar is ignited, and its sulphur oxidized, and the quicksilver vaporized and, condensing in the aludels, flows toward the depression in the central portion of the line. The temperature goes on increasing, until, twelve hours after the beginning of this period, the thermometer shows 212 degrees C. at the first aludels. This lasts for 18 hours, and then the third or "cooling period" begins, which takes from 24 to 26 hours, and during the beginning of which the temperature in the furnaces still rises. It is then opened and cooled down. A very elaborate series of observations made on the temperatures of various parts of the condensing apparatus of the Almaden furnaces has shown that at the aludels nearest to them the heat increases steadily until it reaches 249 degrees C., 44 hours after the beginning of the operation; that in the middle of the line, at the depression, the maximum is 50 degrees 50 hours after starting the fires; and that at the end it does not surpass 39 degrees. In the final condensing chamber, the temperature varied, running downward from 40 degrees during the heating period to 14 degrees, rising again to 29 degrees toward the close.
The loss of the quicksilver during the operation has been vary variously estimated, some stating that it is 50 per cent. and more, while others place it at 30 per cent. Escosura, in his work, gives the details of an operation checked by a royal commission in 1872, according to which the loss in working ore running 9.55 per cent. was only 4.41 per cent.—a loss which he considered inevitable. In 1806, two Idria furnaces were put up at Almaden, but the engineers are not favorably impressed with them. The first cost is stated to be more than ten times greater than that of an aludel furnace, while the capacity is only 50 per cent. greater. One pair of Idria furnaces in five years produced 120,000 kilogrammes of quicksilver, against 843,000 kilogrammes made by eight sets of the Bustamente furnaces, the cost per kilogramme of quicksilver being respectively 0.121 and 0.056 peseta.
While it is undoubtedly true that the discovery of the balloon has very greatly retarded the science of aerostation, yet, in my opinion, its field of usefulness as a vehicle for pleasure excursions, for explorations, and for scientific investigations, has not been fully developed for the want of certain improvements, the nature of which it is the object of this paper to point out. The improvement of which I am about to speak relates to the regulation of the buoyancy of the balloon. This is now done by throwing out ballast or by allowing some of the gas to escape—a method which necessitates the carrying of an unwieldy amount of sand and the expenditure of an unnecessary amount of gas.
From the fire balloon invented by the Montgolfier Brothers, in 1782, to the superior hydrogen balloon of M.M. Charles and Robert, no material advancement has been made, except the employment of coal gas, first suggested by Mr. Green. The vast surface presented to the wind makes the balloon unmanageable in every breeze, and the aeronaut can do nothing but allow it to float along with the current. This is a difficulty which has been partly overcome, as was seen at the recent Paris Electrical Exhibition; but no one will ever be able to guide it in a direction opposite to a current of air. The aeronaut must ever content himself in being able to float in the direction of the current or at certain angles to its course; but to do this even is a matter which has not been successfully accomplished. An inflated balloon would ascend too high unless several hundred pounds of ballast were used to weight it down. This ballast serves another purpose, it is desirable to maintain the balloon at a uniform distance above the earth's surface, and as the two per cent. daily waste of gas diminishes the buoyancy of the balloon, it must be kept from descending by throwing off a certain amount of sand. Again, the heat of the sun and the action of warm air currents cause at times the volume of gas to undergo a sudden expansion, and then to prevent the balloon from running too high, the gas must be allowed to escape from the valve. The gas, under these circumstances, must also be allowed to escape in order to prevent the balloon from bursting. Presently the balloon will pass through a colder current of air and sudden condensation takes place, and the balloon would sink unless more ballast were thrown off. This process continues until the aeronaut has neither ballast nor gas left.
Now, I suggest that a large balloon be made with the mouth closed, so that no gas can escape; and that it carry enough ballast to keep it, under an ordinary temperature, at a certain distance from the ground. A pipe must enter the mouth of the balloon, one end of which opens in its interior and the other end in a gas reservoir which lies in the "basket" or "car." As soon as the gas undergoes an expansion, and a certain amount of pressure is made in this reservoir, a valve opens and a whistle signals the moment when the force pumps must be set to work to pump the air out of the balloon into the largenumber tworeservoir, the frame work of which forms the body of the car. Taking a certain amount of gas out of the balloon is equivalent to taking on more ballast, while by condensing this gas into a large reservoir, it is not allowed to escape, and when necessary can be sent back into the balloon and thus prevent the throwing off of ballast. Coal gas, under a certain pressure, becomes heavier than air (or at least equally heavy), and thus the gas pumped out of the balloon will of itself serve as ballast. This invention will enable the balloonist to keep himself at a uniform distance above the earth, will prevent the carrying of so much ballast and the expensive waste of gas, and will enable him to keep afloat at least ten times as long as by the old method. I have made a model and tested the above theory.
Eli C. Ohmart.
North Manchester, Ind.