p. 135
The Pressure or Head.—In addition to that there will also be 50 pounds pressure on each square inch of the head, as well as on the sides of the cylinder.
Fig. 131shows a cylinder (A), a piston (B) and a steam inlet port (C), in which is indicated how the steam pressure acts equally in all directions. As, however, the piston is the only movable part, the force of the steam is directed to that part, and the motion is then transmitted to the crank, and to the shaft of the engine.
This same thing applies to water which, as stated, is dependent on its head.Fig. 132reprep. 136sents a cylinder (D) with a vertically movable piston (E) and a standpipe (F). Assuming that the pipe (F) is of sufficient height to give a pressure of 50 pounds to the square inch, then the piston (E) and the sides and head of the cylinder (D) would have 50 pounds pressure on every square inch of surface.
Fuels.—In the use of fuels, such as the volatile hydrocarbons, the direct expansive power of the fuel gases developed, is used to move the piston back and forth. Engines so driven are calledInternal Combustion Motors.
Power from Winds.—Another source of power is from the wind acting against wheels which have blades or vanes disposed at such angles that there is a direct conversion of a rectilinear force into circular motion.
In this case power is derived from the force of the moving air and the calculation of energy developed is made by considering the pressure on each square foot of surface. The following table shows the force exerted at different speeds against a flat surface one foot square, held so that the wind strikes it squarely:p. 137
SPEED OF WINDPRESSURESPEED OF WINDPRESSURE5Milesperhour2oz.35milesperhour6lb.2oz.10““88“40““8“15““1lb.2“45““10“2“20““2““50““12“2“25““3“2“55““15“2“30““4“8“60““18“
Varying Degrees of Pressure.—It is curious to notice how the increase in speed changes the pressure against the blade. Thus, a wind blowing 20 miles an hour shows 2 pounds pressure; whereas a wind twice that velocity, or 40 miles an hour, shows a pressure of 8 pounds, which is four times greater than at 20 miles.
It differs, therefore, from the law with respect to water pressure, which is constant in relation to the height or the head—that is, for every 28 inches height of water a pound pressure is added.
Power from Waves and Tides.—Many attempts have been made to harness the waves and the tide and some of them have been successful. This effort has been directed to the work of converting the oscillations of the waves into a rotary motion, and also to take advantage of the to-and-fro movement of the tidal flow. There is a great field in this direction for the ingenious boy.
A Profitable Field.—In no direction of humanp. 138enterprise is there such a wide and profitable field for work, as in the generation of power. It is constantly growing in prominence, and calls for the exercise of the skill of the engineer and the ingenuity of the mechanic. Efficiency and economy are the two great watchwords, and this is what the world is striving for. Success will come to him who can contribute to it in the smallest degree.
Capital is not looking for men who can cheapen the production of an article 50 per cent., but 1 per cent. The commercial world does not expect an article to be 100 per cent, better. Five per cent. would be an inducement for business
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Horse-power.—When work is performed it is designated as horse-power, usually indicated by the letters H. P.; but the unit of work is called afoot pound.
If one pound should be lifted 550 feet in one second, or 550 pounds one foot in the same time, it would be designated as one horse-power. For that reason it is called a foot pound. Instead of using the figure to indicate the power exerted during one minute of time, the time is taken for a minute, in all calculations, so that 550 multiplied by the number of seconds, 60, in a minute, equals 33,000 foot pounds.
Foot Pounds.—The calculation of horse-power is in a large measure arbitrary. It was determined in this way: Experiments show that the heat expended in vaporizing 34 pounds of water per hour, develops a force equal to 33,000 foot pounds; and since it takes about 4 pounds of coal per hour to vaporize that amount of water, the heat developed by that quantity of coal develops the same force as that exercised by an average horse exerting his strength at ordinary work
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All power is expressed in foot pounds. Suppose a cannon ball of sufficient weight and speed strikes an object. If the impact should indicate 33,000 pounds it would not mean that the force employed was one horse-power, but that many foot pounds.
If there should be 60 impacts of 550 pounds each within a minute, it might be said that it would be equal to 1 horse-power, but the correct way to express it would be foot pounds.
So in every calculation, where power is to be calculated, first find out how many foot pounds are developed, and then use the unit of measure, 33,000, as the divisor to get the horse-power, if you wish to express it in that way.
It must be understood, therefore, that horse-power is a simple unit of work, whereas a foot pound is a compound unit formed of a foot paired with the weight of a pound.
Energy.—Nowworkandenergyare two different things. Work is the overcoming of resistance of any kind, either by causing or changing motion, or maintaining it against the action of some other force.
Energy, on the other hand, is the power of doing work. Falling water possesses energy; so does a stone poised on the edge of a cliff. In the case of water, it is calledkineticenergy; in the stonep. 141potentialenergy. A pound of pressure against the stone will cause the latter, in falling, to develop an enormous energy; so it will be seen that this property resides, or is within the thing itself. It will be well to remember these definitions.
How to Find Out the Power Developed.—The measure of power produced by an engine, or other source, is so interesting to boys that a sketch is given of a Prony Brake, which is the simplest form of the Dynamometer, as these measuring machines are called.
Fig. 133. Prony BrakeFig. 133. Prony BrakeToList
In the drawing (A) is the shaft, with a pulley (A´), which turns in the direction of the arrow (B). C is a lever which may be of any length. This has a block (C´), which fits on the pulley, and below the shaft, and surrounding it, are blocks (D) held against the pulley by a chain (E), the ends of the chain being attached to bolts (F) which pass through the block (C´) and lever (C)
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Nuts (G) serve to draw the bolts upwardly and thus tighten the blocks against the shaft. The free end of the lever has stops (H) above and below, so as to limit its movement. Weights (I) are suspended from the end of the lever.
Fig. 134. Speed IndicatorFig. 134. Speed IndicatorToList
The Test.—The test is made as follows: The shaft is set in motion, and the nuts are tightened until its full power at the required speed is balanced by the weight put on the platform.
The following calculation can then be made:
For our present purpose we shall assume that the diameter of the pulley (A´) is 4 inches; the length of the lever (C), 3 feet; the speed of the shaft (A) and the pulley, 210 revolutions per minute; and the weight 600 pounds.
Now proceed as follows:
(1) Multiply the diameter of the pulley (A´)p. 143(4 inches) by 3.1416, and this will give the circumference 12.5664 inches; or, 1.0472 feet.
(2) Multiply this product (1.0472) by the revolutions per minute. 1.0472 × 210 = 219.912. This equals thespeedof the periphery of the pulley.
(3) The next step is to get the length of the lever (C) from the center of the shaft (A) to the point from which the weights are suspended, and divide this by one-half of the diameter of the pulley (A´). 36" ÷ 2" = 18", or 11/2feet. This is theleverage.
(4) Then multiply theweightin pounds by theleverage. 600 × 11/2= 900.
(5) Next multiply this product (900) by thespeed, 900 × 219.912 = 197,920.8, which meansfoot pounds.
(6) As each horse-power has 33,000 foot pounds, the last product should be divided by this figure, and we have 197,920.8 ÷ 33,000 = 5.99 H. P.
The Foot Measure.—How long is a foot, and what is it determined by? It is an arbitrary measure. The human foot is the basis of the measurement. But what is the length of a man's foot? It varied in different countries from 9 to 21 inches.
In England, in early days, it was defined as a measure of length consisting of 12 inches, or 36 barleycorns laid end to end. But barleycorns differ in length as well as the human foot, so thep. 144standard adopted is without any real foundation or reason.
Weight.—To determine weight, however, a scientific standard was adopted. A gallon contains 8.33 pounds avoirdupois weight of distilled water. This gallon is divided up in two ways; one by weight, and the other by measurement.
Each gallon contains 231 cubic inches of distilled water. As it has four quarts, each quart has 573/4cubic inches, and as each quart is comprised of two pints, each pint has nearly 29 cubic inches.
The Gallon.—The legal gallon in the United States is equal to a cylindrical measure 7 inches in diameter and 6 inches deep.
Notwithstanding the weights and dimensions of solids and liquids are thus fixed by following a scientific standard, the divisions into scruples, grains, pennyweights and tons, as well as cutting them up into pints, quarts and other units, is done without any system, and for this reason the need of a uniform method has been long considered by every country.
The Metric System.—As early as 1528, Fernal, a French physician, suggested the metric system. Our own government recognized the value of this plan when it established the system of coinage.
The principle lies in fixing a unit, such as a dolp. 145lar, or a pound, or a foot, and then making all divisions, or addition, in multiples of ten. Thus, we have one mill; ten mills to make a dime; ten dimes to make a dollar, and so on.
Basis of Measurement.—The question arose, what to use as the basis of measurement, and it was proposed to use the earth itself, as the measure. For this purpose the meridian line running around the earth at the latitude of Paris was selected.
One-quarter of this measurement around the globe was found to be 393,707,900 inches, and this was divided into 10,000,000 parts. Each part, therefore, was a little over 39.37 inches in length, and this was called a meter, which meansmeasure.
A decimeter is one-tenth of that, namely, 3.937 inches; and a decameter 39.37, or ten times the meter, and so on.
For convenience the metrical table is given, showing lengths in feet and inches, in which only three decimal points are used.
Metrical Table, showing measurements in feet and inches:p. 146
LengthInchesFeetMillimeter0.0390.003Centimeter0.3930.032Decimeter3.9370.328Meter39.3703.280Decameter393.70732.808Hectometer3937.079328.089Kilometer39370.7903280.899Myriameter393707.90032808.992
1 Myriameter= 5.4 nautical miles, or 6.21 statute miles.1 Kilometer= 0.621 statute mile, or nearly5/8mile.1 Hectometer= 109.4 yards.1 Decameter= 0.497 chain, 1.988 rods.1 Meter= 39.37 inches, or nearly 3 ft. 33/8inches.1 Decimeter= 3.937 inches.1 Centimeter= 0.3937 inch.1 Millimeter= 0.03937 inch.1 Micron=1/25400inch.1 Hectare= 2.471 acres.1 Arc= 119.6 square yards.1 Centaire, or square meter= 10.764 square feet.p. 1471 Decastere= 13 cubic yards, or about 23/4cords.1 Stere, or cubic meter= 1.308 cubic yards, or 35.3 cubic feet.1 Decistere= 31/2cubic feet.1 Kiloliter= 1 ton, 12 gal., 2 pints, 2 gills old wine measure.1 Hectoliter= 22.01 Imperial gals., or 26.4 U. S. gals.1 Decaliter= 2 gallons, 1 pint, 22/5gills, imperial measure, or 2 gals., 2 qts., 1 pt.,1/2gill, U. S.1 Liter= 1 pint, 3 gills, imperial, or 1 qt.,1/2gill U. S. measure.1 Decileter= 0.704 gill, imperial, or 0.845 gill U. S. measure.1 Millier= 2,204.6 pounds avoirdupois.1 Metric quintal= 2 hundredweight, less 31/2pounds, or 220 pounds, 7 ounces.1 Kilogram= 2 pounds, 3 ounces, 43/8drams avoirdupois.1 Hectogram= 3 ounces, 83/8drams avoirdupois.1 Decagram= 154.32 grains Troy.1 Gram= 15.432 grains.1 Decigram= 1.542 grain.1 Centigram= 0.154 grain.1 Milligram= 0.015 grain.
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To find the circumference of a circle: Multiply the diameter by 3.1416.
To find the diameter of a circle: Multiply the circle by .31831.
To find the area of a circle: Multiply the square of the diameter by .7854.
To find the area of a triangle: Multiply the base by one-half the perpendicular height.
To find the surface of a ball: Multiply the square of the diameter by 3.1416.
To find the solidity of a sphere: Multiply the cube of the diameter by .5236.
To find the cubic contents of a cone: Multiply the area of the base by one-third the altitude.
Doubling the diameter of a pipe increases its capacity four times.
To find the pressure in pounds per square inch of a column of water: Multiply the height of the column in feet by .434.
Standard Horse-power: The evaporation of 30 pounds of water per hour from a feed water temperature of 1,000 degrees Fahrenheit into steam at 70 pounds gauge pressure
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To find the capacity of any tank in gallons: Square the diameter in inches, multiply by the length, and then by .0034.
In making patterns for aluminum castings provision must be made for shrinkage to a greater extent than with any other metal or alloy.
The toughness of aluminum can be increased by adding a small per cent. of phosphorus.
All alloys of metals having mercury are calledamalgams.
A sheet of zinc suspended in the water of a boiler will produce an electrolytic action and prevent scaling to a considerable extent.
Hydrofluoric acid will not affect a pure diamond, but will dissolve all imitations.
A strong solution of alum put into glue will make it insoluble in water.
A grindstone with one side harder than the other can have its flinty side softened by immersing that part in boiled linseed oil.
One barrel contains 33/4cubic feet.
One cubic yard contains 7 barrels.
To find the speed of a driven pulley of a given diameter: Multiply the diameter of the driving pulley by its speed or number of revolutions. Divide this by the diameter of the driven pulley. The result will be the number of revolutions of the driven pulley
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To find the diameter of a driven pulley that shall make any given number of revolutions in the same time: Multiply the diameter of the driving pulley by its number of revolutions, and divide the product by the number of revolutions of the driven pulley.
A piece of the well-known tar soap held against the inside of a belt while running will prevent it from slipping, and will not injure the belt.
Boiler scale is composed of the carbonate or the sulphate of lime. To prevent the formation it is necessary to use some substance which will precipitate these elements in the water. The cheapest and most universally used for this purpose are soda ash and caustic soda.
Gold bronze is merely a mixture of equal parts of oxide of tin and sulphur. To unite them they are heated for some time in an earthen retort.
Rusted utensils may be cleaned of rust by applying either turpentine or kerosene oil, and allowing them to stand over night, when the excess may be wiped off. Clean afterwards with fine emery cloth.
Plaster of paris is valuable for many purposes in a machine shop, but the disadvantage in handling it is, that it sets so quickly, and its use is, therefore, very much limited. To prevent quick setting mix a small amount of arrow root powder withp. 151the plaster before it is mixed, and this will keep it soft for some time, and also increase its hardness when it sets.
For measuring purposes a tablespoon holds1/2ounce; a dessertspoon1/4ounce; a teaspoon1/8ounce; a teacupful of sugar weighs1/2pound; two teacupsful of butter weigh 1 pound; 11/3pints of powdered sugar weigh 1 pound; one pint of distilled water weighs 1 pound.
Ordinarily, 450 drops of liquid are equal to 1 ounce; this varies with different liquids, some being thicker in consistency than others, but for those of the consistency of water the measure given is fairly accurate
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If there is anything in the realm of mechanics which excites the wonder and admiration of man, it is the knowledge that the greatest inventions are the simplest, and that the inventor must take advantage of one law in nature which is universal in its application, and that is vibration.
There is a key to every secret in nature's great storehouse. It is not a complicated one, containing a multiplicity of wards and peculiar angles and recesses. It is the very simplicity in most of the problems which long served as a bar to discovery in many of the arts. So extremely simple have been some of the keys that many inventions resulted from accidents.
Invention Precedes Science.—Occasionally inventions were brought about by persistency and energy, and ofttimes by theorizing; but science rarely ever aids invention. The latter usually precedes science. Thus, reasoning could not show how it might be possible for steam to force water into a boiler against its own pressure. But the injector does this
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If, prior to 1876, it had been suggested that a sonorous vibration could be converted into an electrical pulsation, and transformed back again to a sonorous vibration, science would have proclaimed it impossible; but the telephone does it. Invention shows how things are done, and science afterwards explains the phenomena and formulates theories and laws which become serviceable to others in the arts.
Simplicity in Inventions.—But let us see how exceedingly simple are some of the great discoveries of man.
The Telegraph.—The telegraph is nothing but a magnet at each end of a wire, with a lever for an armature, which opens and closes the circuit that passes through the magnets and armature, so that an impulse on the lever, or armature, at one end, by making and breaking the circuit, also makes and breaks the circuit at the other end.
Telephone.—The telephone has merely a disk close to but not touching the end of a magnet. The sonorous vibration of the voice oscillates the diaphragm, and as the diaphragm is in the magnetic field of the magnet, it varies the pressure, so called, causing the diaphragm at the other end of the wire to vibrate in unison and give out the same sound originally imparted to the other diaphragm.
Transmitter.—The transmitter is merely a senp. 154sitized instrument. It depends solely on the principle of light contact points in an electric circuit, whereby the vibrations of the voice are augmented.
Phonograph.—The phonograph is not an electrical instrument. It has a diaphragm provided centrally with a blunt pin, or stylus. To make the record, some soft or plastic material, like wax, or tinfoil, is caused to move along so that the point of the stylus makes impressions in it, and the vibrations of the diaphragm cause the point to traverse a groove of greater or smaller indentations. When this groove is again presented to the stylus the diaphragm is vibrated and gives forth the sounds originally imparted to it when the indentations were made.
Wireless Telegraphy.—Wireless telegraphy depends for its action on what is called induction. Through this property a current is made of a high electro-motive force, which means of a high voltage, and this disturbs the ether with such intensity that the waves are sent out in all directions to immense distances.
The great discovery has been to find a mechanism sensitive enough to detect the induction waves. The instrument for this purpose is called a coherer, in which small particles cohere through the action of the electric waves, and are caused to fall apart mechanically, during the electrical impulses
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Printing Telegraph.—The printing telegraph requires the synchronous turning of two wheels. This means that two wheels at opposite ends of a wire must be made to turn at exactly the same rate of speed. Originally, this was tried by clock work, but without success commercially, for the reason that a pendulum does not beat with the same speed at the equator, as at different latitudes, nor at altitudes; and temperature also affects the rate. The solution was found by making the two wheels move by means of a timing fork, which vibrates with the same speed everywhere, and under all conditions.
Electric Motor.—The direct current electric motor depends for its action on the principle that likes repel, and unlikes attract. The commutator so arranges the poles that at the proper points, in the revolution of the armature, the poles are always presented to each other in such a way that as they approach each other, they are opposites, and thus attract, and as they recede from each other they repel. A dynamo is exactly the same, except that the commutator reverses the operation and makes the poles alike as they approach each other, and unlike as they recede.
Steel is simply iron, to which has been added a small per cent of carbon.
Quinine is efficient in its natural state, but it hasp. 156been made infinitely more effectual by the breaking up or changing of the molecules with acids. Sulphate of quinine is made by the use of sulphuric acid as a solvent.
Explosions.—Explosions depend on oxygen. While this element does not burn, a certain amount of it must be present to support combustion. Thus, the most inflammable gas or liquid will not burn or explode unless oxygenized. Explosives are made by using a sufficient amount, in a concentrated form, which is added to the fuel, so that when it is ignited there is a sufficient amount of oxygen present to support combustion, hence the rapid explosion which follows.
Vibration in Nature.—The physical meaning of vibration is best illustrated by the movement of a pendulum. All agitation is vibration. All force manifests itself in this way.
The painful brilliancy of the sun is produced by the rapid vibrations of the rays; the twinkle of the distant star, the waves of the ocean when ruffled by the winds; the shimmer of the moon on its crested surface; the brain in thinking; the mouth in talking; the beating of the heart; all, alike, obey the one grand and universal law of vibratory motion.
Qualities of Sound.—Sound is nothing but a succession of vibrations of greater or less magnitude. Pitch is produced by the number of vibrap. 157tions; intensity by their force; and quality by the character of the article vibrated.
Since the great telephone controversy which took place some years ago there has been a wonderful development in the knowledge of acoustics, or sounds. It was shown that the slightest sound would immediately set into vibration every article of furniture in a room, and very sensitive instruments have been devised to register the force and quality.
The Photographer's Plate.—It is known that the chemical action of an object on a photographer's plate is due to vibration; each represents a force of different intensity, hence the varying shades produced. Owing to the different rates of vibrations caused by the different colors, the difficulty has been to photograph them, but this has now been accomplished. Harmony, or "being in tune," as is the common expression, is as necessary in light, as in music.
Some chemicals will bring out or "develop," the pictures; others will not. Colors are now photographed because invention and science have found the harmonizing chemicals.
Quadruplex Telegraphy.—One of the most remarkable of all the wonders of our age is what is known as duplex and quadruplex telegraphy. Every atom and impulse in electricity is oscillation.p. 158The current which transmits a telegram is designated in the science as "vibratory."
But how is it possible to transmit two or more messages over one wire at the same time? It is by bringing into play the harmony of sounds. One message is sent in one direction in the key of A; another message in the other direction in B; and so any number may be sent, because the electrical vibrations may be tuned, just like the strings of a violin.
Electric Harmony.—Every sound produces a corresponding vibration in surrounding objects. While each vibrates, or is capable of transmitting a sound given to it by its vibratory powers, it may not vibrate in harmony.
When a certain key of a piano is struck every key has a certain vibration, and if we could separate it from the other sounds, it would reflect the same sound as the string struck, just the same as the walls of a room or the air itself would convey that sound.
But as no two strings in the instrument vibrate the same number of times each second, the rapid movement of successive sounds of the keys do not interfere with each other. If, however, there are several pianos in a room, and all are tuned the same pitch, the striking of a key on one instrument willp. 159instantly set in vibration the corresponding strings in all the other instruments.
This is one reason why a piano tested in a music wareroom has always a more beautiful and richer sound than when in a drawing-room or hall, since each string is vibrated by the other instrument.
If a small piece of paper is balanced upon the strings of a violin, every key of the piano may be struck, except the one in tune, without affecting the paper; but the moment the same key is struck the vibration of the harmonizing pitch will unbalance the paper.
The musical sound of C produces 528 vibrations per second; D 616, and so on. The octave above has double the number of vibrations of the lower note. It will thus be understood why discord in music is not pleasant to the ear, as the vibrations are not in the proper multiples.
Odors.—So with odors. The sense of smell is merely the force set in motion by the vibration of the elements. An instrument called theodophonedemonstrates that a scale or gamut exists in flowers; that sharp smells indicate high tones and heavy smells low tones. Over fifty odors have thus been analyzed.
The treble clef, note E, 4th space, is orange; note D, 1st space below, violet; note F, 4th space above clef, ambergris. To make a proper bouquet, therep. 160fore the different odors must be harmonized, just the same as the notes of a musical chord are selected.
A Bouquet of Vibrations.—The odophone shows that santal, geranium, orange flower and camphor, make a bouquet in the key of C. It is easy to conceive that a beautiful bouquet means nothing more than an agreeable vibratory sensation of the olfactory nerves.
Taste.—So with the sense of taste. The tongue is covered with minute cells surrounded by nervous filaments which are set in motion whenever any substance is brought into contact with the surface. Tasting is merely the movement of these filaments, of greater or less rapidity.
If an article is tasteless, it means that these filaments do not vibrate. These vibrations are of two kinds. They may move faster or slower, or they may move in a peculiar way. A sharp acute taste means that the vibrations are very rapid; a mild taste, slow vibrations.
When a pleasant taste is detected, it is only because the filaments are set into an agreeable motion. The vibrations in the tongue may become so rapid that it will be painful, just as a shriek becomes piercing to the ear, or an intense light dazzling to the eye; all proceed from the same physical force acting on the brain
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Color.—Color, that seemingly unexplainable force, becomes a simple thing when the principles of vibration are applied, and this has been fully explained by the spectroscope and its operation.
When the boy once appreciates that this force, or this motion in nature is just as simple as the great inventions which have grown out of this manifestation, he will understand that a knowledge of these things will enable him to utilize the energy in a proper way
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In a work of this kind, dealing with the various elements, the boy should have at hand recipes or formulas for everything which comes within the province of his experiments. The following are most carefully selected, the objects being to present those which are the more easily compounded.
Adhesives for Various Uses.—Waterproof glue. Use a good quality of glue, and dissolve it in warm water, then add one pound of linseed oil to eight pounds of the glue. Add three ounces of nitric acid.
Leather or Card-board Glue. After dissolving good glue in water, to which a little turpentine has been added, mix it with a thick paste of starch, the proportion of starch to glue being about two to every part of glue used. The mixture is used cold.
A fine Belt Glue. Dissolve 50 ounces of gelatine in water, and heat after pouring off the excess water. Then stir in five ounces of glycerine, ten ounces of turpentine, and five ounces of linseed oil varnish. If too thick add water to suit.
For cementing Iron to Marble. Use 30 parts of Plaster of Paris, 10 parts of iron filings, and onep. 163half part of sal ammoniac. These are mixed up with vinegar to make a fluid paste.
To cement Glass to Iron. Use 3 ounces of boiled linseed oil and 1 part of copal varnish, and into this put 2 ounces of litharge and 1 ounce of white lead and thoroughly mingle so as to make a smooth paste.
Water-proof Cement. Boiled linseed oil, 6 ounces; copal, 6 ounces; litharge, 2 ounces; and white lead, 16 ounces. To be thoroughly incorporated.
To unite rubber or leather to hard substances. One ounce of pulverized gum shellac dissolved in 91/2ounces of strong ammonia, will make an elastic cement. Must be kept tightly corked.
For uniting iron to iron. Use equal parts of boiled oil, white lead, pipe clay and black oxide of manganese, and form it into a paste.
Transparent Cement. Unite 1 ounce of india rubber, 67 ounces of chloroform, and 40 ounces of mastic. This is to be kept together for a week, and stirred at times, when it will be ready for use.
To Attach Cloth to Metal. Water 100 parts, sugar 10 parts, starch 20 parts, and zinc chloride 1 part. This must be first stirred and made free of lumps, and then heated until it thickens.
United States Government Gum. Dissolve 1 part of gum arabic in water and add 4 parts of sugarp. 164and 1 part of starch. This is then boiled for a few minutes, and thinned down as required.
To Make Different Alloys.—Silver-aluminum. Silver one-fourth part, and aluminum three-fourth parts.
Bell-metal. Copper, 80 parts; tin, 20 parts. Or, copper, 72 parts; tin, 26 parts; zinc, 2 parts. Or, copper 2; 1 of tin.
Brass. Copper, 66 parts; zinc, 32 parts; tin, 1 part; lead, 1 part.
Bronzes. Copper, 65 parts; zinc, 30 parts; tin, 5 parts. Or, copper, 85 parts; zinc, 10 parts; tin, 3 parts; lead, 2 parts.
German Silver. 52 parts of copper; 26 parts zinc; 22 parts nickel.
For Coating Mirrors. Tin, 70 parts; mercury, 30 parts.
Boiler Compounds.—To prevent scaling. Use common washing soda, or Glauber salts.
To Dissolve Celluloid.—Use 50 parts of alcohol and 5 parts of camphor for every 5 parts of celluloid. When the celluloid is put into the solution it will dissolve it.
To Soften Celluloid. This may be done by simply heating, so it will bend, and by putting it in steam, it can be worked like dough.
Clay Mixture for Forges.—Mix dry 20 parts of fire clay, 20 parts cast-iron turnings, one partp. 165of common salt, and1/2part sal ammoniac, and then add water while stirring, so as to form a mortar of the proper consistency. The mixture will become very hard when heat is applied.
A Modeling Clay. This is made by mixing the clay with glycerine and afterwards adding vaseline. If too much vaseline is added it becomes too soft.
Fluids for Cleaning Clothes, Furniture, Etc.—For Delicate Fabrics. Make strong decoction of soap bark, and put into alcohol.
Non-inflammable Cleaner. Equal parts of acetone, ammonia and diluted alcohol.
Taking dried paint from clothing. Shake up 2 parts of ammonia water with 1 part of spirits of turpentine.
Cleaning Furniture, etc. Unite 2.4 parts of wax; 9.4 parts of oil of turpentine; 42 parts acetic acid; 42 parts citric acid; 42 parts white soap. This must be well mingled before using.
Removing Rust from Iron or Steel. Rub the surface with oil of tartar. Or, apply turpentine or kerosene, and after allowing to stand over night, clean with emery cloth.
For Removing Ink Stains from Silver. Use a paste made of chloride of lime and water.
To clean Silver-Plated Ware. Make a mixture of cream of tartar, 2 parts; levigated chalk, 2p. 166parts; and alum, 1 part. Grind up the alum and mix thoroughly.
Cleaning a Gas Stove. Make a solution of 9 parts of caustic soda and 150 parts of water, and put the separate parts of the stove in the solution for an hour or two. The parts will come out looking like new.
Cleaning Aluminum. A few drops of sulphuric acid in water will restore the luster to aluminum ware.
Oil Eradicator. Soap spirits, 100 parts; ammonia solution, 25; acetic ether, 15 parts.
Disinfectants.—Camphor, 1 ounce; carbolic acid (75 per cent.), 12 ounces; aqua ammonia, 10 drachms; soft salt water, 8 drachms.
Water-Closet Deodorant. Ferric chloride, 4 parts; zinc chloride, 5 parts; aluminum chloride, 4 parts; calcium chloride, 5 parts; magnesium chloride, 3 parts; and water sufficient to make 90 parts. When all is dissolved add to each gallon 10 grains of thymol and a quarter-ounce of rosemary that had been previously dissolved in six quarts of alcohol.
Odorless Disinfectants. Mercuric chloride, 1 part; cupric sulphate, 10 parts; zinc sulphate, 50 parts; sodium chloride, 65 parts; water to make 1,000 parts.
Emery for Lapping Purposes. Fill a pint bottlep. 167with machine oil and emery flour, in the proportion of 7 parts oil and 1 part emery. Allow it to stand for twenty minutes, after shaking up well, then pour off half the contents, without disturbing the settlings, and the part so poured off contains only the finest of the emery particles, and is the only part which should be used on the lapping roller.
Explosives.—Common Gunpowder. Potassium nitrate, 75 parts; charcoal, 15 parts; sulphur, 10 parts.
Dynamite. 75 per cent. nitro-glycerine; 25 per cent. infusorial earth.
Giant Powder. 36 per cent. nitro-glycerine; 48 per cent. nitrate of potash; 8 per cent. of sulphur; 8 per cent. charcoal.
Fulminate. Chlorate of potassia, 6 parts; pure lampblack, 4 parts; sulphur, 1 part. A blow will cause it to explode.
Files.—How to Keep Clean. Olive oil is the proper substance to rub over files, as this will prevent the creases from filling up while in use, and preserve the file for a longer time, and also enable it to do better cutting.
To Renew Old Files. Use a potash bath for boiling them in, and afterwards brush them well so as to get the creases clean. Then stretch a cotton cloth between two supports, and after plunging thep. 168file into nitric acid, use the stretched cloth to wipe off the acid. The object is to remove the acid from the ridges of the file, so the acid will only eat out or etch the deep portions between the ridges, and not affect the edges or teeth.
Fire Proof Materials or Substances.—For Wood. For the kind where it is desired to apply with a brush, use 100 parts sodium silicate; 50 parts of Spanish white, and 100 parts of glue. It must be applied hot.
Another good preparation is made as follows: Sodium silicate, 350 parts; asbestos, powdered, 350 parts; and boiling water 1,000 parts.
For Coating Steel, etc. Silica, 50 parts; plastic fire clay, 10 parts; ball clay, 3 parts. To be thoroughly mixed.
For Paper. Ammonium sulphate, 8 parts; boracic acid, 3 parts; borax, 2 parts; water, 100 parts. This is applied in a liquid state to the paper surface.
Floor Dressings.—Oil Stain. Neats' foot oil, 1 part; cottonseed oil, 1 part; petroleum oil, 1 part. This may be colored with anything desired, like burnt sienna, annatto, or other coloring material.
Ballroom Powder. Hard paraffine, 1 pound; powdered boric acid, 7 pounds; oil of lavender, 1 drachm; oil of neroli, 20 minims.
Foot Powders.—For Perspiring Feet. Balsamp. 169Peru, 15 minims; formic acid, 1 drachm; chloral hydrate, 1 drachm; alcohol to make 3 ounces.
For Easing Feet. Tannaform, 1 drachm; talcum, 2 drachms; lycopodium, 30 grains.
Frost Bites. Carbolized water, 4 drachms; nitric acid, 1 drop; oil of geranium, 1 drop.
Glass.—To cut glass, hold it under water, and use a pair of shears.
To make a hole through glass, place a circle of moist earth on the glass, and form a hole in this the diameter wanted for the hole, and in this hole pour molten lead, and the part touched by the lead will fall out.
To Frost Glass. Cover it with a mixture of 6 ounces of magnesium sulphate, 2 ounces of dextrine, and 20 ounces of water. This produces a fine effect.
To imitate ground glass, use a composition of sandarac, 21/2ounces; mastic,1/2ounce; ether, 24 ounces; and benzine, 16 ounces.
Iron and Steel.—How to distinguish them. Wash the metal and put it into a solution of bichromate of potash to which has been added a small amount of sulphuric acid. In a minute or so take out the metal, wash and wipe it. Soft steel and cast iron will have the appearance of an ash-gray tint; tempered steels will be black; and pudp. 170dled or refined irons will be nearly white and have a metallic reflection.
To Harden Iron or Steel. If wrought iron, put in the charge 20 parts, by weight, of common salt, 2 parts of potassium cyanide, .3 part of potassium bichromate, .15 part of broken glass.
To harden cast iron, there should be added to the charge the following: To 60 parts of water, add 21/2parts of vinegar, 3 parts of common salt, and .25 part of hydrochloric acid.
To soften castings: Heat them to a high temperature and cover them with fine coal dust and allow to cool gradually.
Lacquers.—For Aluminum. Dissolve 100 parts of gum lac in 300 parts of ammonia and heat for an hour moderately in a water bath. The aluminum must be well cleaned before applying. Heat the aluminum plate afterwards.
For Brass. Make a compound as follows; Annatto,1/4ounce; saffro,1/4ounce; turmeric, 1 ounce; seed lac, 3 ounces; and alcohol, 1 pint. Allow the mixture to stand for three days, then strain in the vessel which contains the seed lac, and allow to stand until all is dissolved.
For Copper. Heat fine, thickly liquid amber varnish so it can be readily applied to the copper, and this is allowed to dry. Then heat the coated object until it commences to smoke and turn brown