Snow plays an important part in the economy of nature. In the first place, the mere transformation of the water particles into ice is a process during which a large amount of heat is given out; so that we may regard the formation of snow renders the air currents warmer than they would otherwise be. Fallen snow serves to protect the ground, for, owing to its loose texture, it is a bad conductor of heat; so that, while checking the radiation of heat from the earth into space, it does not draw off the earth's heat by conduction. The ground is thus often 23 degrees to 30 degrees warmer than the surface of the snow above, and sometimes the difference of temperature has been more than 40 degrees.

Red snow and green snow have been met with, more commonly in Arctic regions, but also in other parts of the world. These colours are caused by the presence of minute organisms—a species of alga called Protococcus nivalis.

The snow line of mountains is on the slopes below which, all the snow which falls in the year, melts during the summer. Above the snow line, therefore, lies the region of perpetual snow. The altitude of the snow line depends on a variety of conditions. The latitude of a snow range is, of course, important in determining the position of the snow line, but many other circumstances have to be considered, as the shape and slope of the mountain, the aspect of either side of the range, the character of the surrounding country, the prevalent winds, and so on.

The following table shows the observed height of the snow line in feet above the sea level in different places:

DESIGNING, MAKING, AND INFLATING PAPER BALLOONS

Draw a rough figure of the balloon, as shown at A, (Fig. 211.)

Divide this into any number of parts (the more the better) by horizontal lines. Take a radius of balloon on each line, and describe circles, B.

Divide this into twelve parts by radius lines, then make pattern as follows: Draw a perpendicular, C, with horizontal lines at distance of horizontal lines on A, but measured on circumference as c d. Then set off on each line from perpendicular one half the distance between the radius lines, B, on the corresponding circle as e f; draw line through points thus found, and result will be shape of each section. Allow a little on one side when cutting out for pasting. This will be best made with strong tissue paper of any colour desired.

Another method, giving a shape somewhat different, is shown in Fig. 212. First draw an elevation of the balloon it is intended to make, either full size, on the floor, or to scale. The shape here illustrated differs slightly from that of balloons usually sold ready made, being wider at the mouth. This shape, however, is not so liable to catch fire when swayed about by the wind. Divide the elevation into any number of parts (the more the better) by horizontal lines as shown (No. 1). Take the radius of the balloon on each line, as A B, describe circles (No. 2), and divide these into twelve parts by radial lines. Then to make a pattern, draw a perpendicular (No. 3), with horizontal lines at the distance of the horizontal lines (No. 1,) but measured on the circumference as C D. Then set off on each line from the perpendicular half the distance between the radius lines (No. 2), on the corresponding circle as E F, and draw a line through the points thus found, and the result will be the shape of each section. Allow a little (say ¹⁄₄ inch), on one side when cutting out for pasting. Each section will be made up of one, two, or three pieces, according to the size of the balloon to be made. If the pieces are cut as shown (No. 4,) a great saving of paper results. To paste these pieces together, place them in a pile on the table or bench with the edges flush and a piece of waste paper under the pile. Now rub the top sheet with the thumb nail until each piece is moved back from the one immediately under it about one-fourth inch. Place a piece of waste paper about the same distance from the edge of the top sheet, and pass the paste brush over the whole of the exposed edges. No. 5 will explain what is meant. Now place two of the completed sections together so as to look like No. 3, with a small part projecting as shown by the dotted line G. Paste the edge of the under section—that is, the part hatched—and turn it over on to the dotted line H. When each two of the sections have been joined in this way, proceed in the same manner to join these together till the whole is completed. A circular piece of paper is cut out to join the sections at the top, and a loop of string should be pasted to the top to suspend the balloon while inflating. A ring of wire with two cross pieces is fitted to the bottom of the balloon, and the inflammable material,—tow soaked in methylated spirits—is fastened to the junction of the cross pieces.

MAGNETIZED WATCHES

The owner of a good American watch was a little troubled concerning it, because it had been running irregularly for some time past. It came out that he had visited the electric power house and had stayed for some time examining the works and machinery, so that parts of his watch had evidently become magnetized by the influence of the dynamos. The watch had been made some time ago, and had not the power to resist, or neutralize electric influences, that most watches have now.

To demagnetize the watch would bring it back to its original condition, but a second visit to the lighting plant would again spoil its time-keeping qualities. The watchmakers now have a way of making watches so that they are not affected by magnetism, but comparatively few of the time pieces in use are non-magnetic, and the average watch is subject to these seasons of fickleness.

The exceedingly fine and exact construction of the watch is not realized by the average possessor of the article. An examination of the works of a watch shows the mechanism as now constructed, although very small in size, to be accurately planned and executed. Changes of temperature are provided for, so that the movement is automatically adjusted. The mainspring and train of gears are usually concealed, while the balance and hair springs are in full view when the case is open. Upon the regularity of the movement of the balance depends the time keeping quality of the watch. On looking closely at the balance, you will observe that it is not a complete ring, but two halves supported at one end. These rings bear a number of large-headed screws, placed at irregular distances, which give it the exact weight and balance required. These half rings will also be found, on looking closely, to be composed of two metals so closely joined that a difference in colour alone gives evidence of the quality. This arrangement of iron and brass, on account of their different coefficients of expansion and contraction with changes of temperature, has been so carefully constructed that, with changes of temperature, the balance assumes such forms as to give it a uniform rate of motion.

The parts affected by magnetism are the balance and springs. The balance in an ordinary watch moves five times a second, 18,000 times an hour, and 432,000 times each day; but a slight change in the forces that move it is necessary to make a difference of several minutes each day. As the balance moves back and forth, the magnetism of the mainspring is pulling or pushing it. If this force were constant, and always in the same direction, the watch would run uniformly. Such, however, is not the case. When the mainspring is tightly wound, its magnetic poles are in a certain direction, and in unwinding they are constantly changing, so that the direction of this force is also constantly changed. The effect on the balance is to cause the watch to run too fast sometimes, and too slow at other times.

Non-magnetic watches are made with these parts of a non-magnetic metal, so that they are not influenced by electric machinery. For testing watches a small compass is used. When placed over the balance, the needle will vibrate with the motion of the balance in proportion to its magnetism.

A BOY'S WHEEL-BARROW

The bottom, sides, and ends were about three-quarters of an inch thick. Good white and red pine were used for the purpose. The stiles and rails of the bottom framework were mortised and tenoned together as shown at Fig. 213; these may be just stubbed together, or the tenons of the rails can go right through the stiles. The most satisfactory job is to groove the sides and ends together, and put all together with oil paint in the joints. If the joints are painted before the framework of the barrow is put together, it will last for years; otherwise, being a boy's wheel-barrow, it would likely often be forgotten and left out in the rain, and the joints getting wet would hasten decay. Two coats of good oil paint, Indian red, will give it a very nice appearance. This barrow, while not intended for heavy work, is capable of carrying quite a load. The wheel was cut out of a piece of plank about 1¹⁄₂ inches thick, hooped up with an iron tire made from heavy hoop iron. The axle was made of wood with a ³⁄₄-inch round iron rod running lengthwise through it and projecting about three inches through on each end. The arbours or boxing, in which ran the ends of the round rod, were formed on the ends of the handle stiles, as may be seen in the illustration. The cost of all the materials for this really useful article was less than $1.50, all told.

VACUUM CLEANERS

A single hand vacuum cleaner can be made from a powerful suction pump, as indicated in the sketch Fig. 214. This should be connected with a metallic box by means of a flexible armoured rubber hose, covered at the end with a piece of fine wire gauze to prevent large particles of dust, etc., being drawn into the pump. To another opening of the box should be fastened another flexible rubber tube, with a bell-shaped metal attachment at the end. The bell-shaped arrangement should be held closely to the carpet while the pump is in action. Within the box, the pipe to which the pump is attached should be bent upward, so that the rush of air shall not bring the dust with it; the object being to collect the dust in the box. A lid covers the box so that it can be emptied from time to time. The success of this arrangement depends on the strength of the pump; if it be a weak one, the inrush of air through the funnel will be so slight that the dust will not be raised.

Rotary pumps are not satisfactory for vacuum cleaners. The best type for this work is a plunger, having a large displacement, with a comparatively short stroke in proportion to the diameter. A suitable pump is shown in the accompanying illustrations. Fig. 214, shows the section of a single barrel, but should a greater supply be required, two barrels may be worked and connected as shown in Fig. 216. The pump is easily made, and of light construction. In Fig. 215, is a brass cylinder with a flange at the bottom; this may be made out of a length of 3-inch brass tube with a flange cut from ¹⁄₈-inch sheet brass. The barrel is 8 inches long. G is the plunger, which may be constructed as a piston; but in the drawing, it is adapted to the arrangement that is shown in Fig. 216. With a piston will be required a guide for the rod at the top of the cylinder. E is a hydraulic cup, its leather kept soft and pliable by oiling. B is the base, which is hollow, and may be built up in sheet metal. At the centre at J, the base is divided into two compartments, one side being the inlet to the pump from the dust box, and the other in communication with the outlet valve C. C and D are two valves with guards. The valves are discs of very soft and pliable leather, well saturated with grease, D being the inlet from the dust box, and C the outlet to the atmosphere. The drawing clearly shows the construction of the other parts. Fig. 216 shows two pumps fitted to one base and worked by a rocking lever; both pumps are in communication with the one inlet N. This arrangement of pumps is easy to work, portable, and well adapted to domestic purposes in cleaning carpets.

Fig. 217, which is reproduced from The Scientific American, exhibits an ingenious form of vacuum cleaner. It has recently been patented, and consists of a suction-fan operated by a water-motor that may be attached to the ordinary kitchen faucet. A tube is connected with the chamber of the suction-fan, and this terminates in a suitable nozzle, or foot plate, which may be moved over a carpet or rug to draw out the dust and dirt. One of the advantages of this system is that dirt drawn up by the suction fan can be carried away with the water down the kitchen drain.

A good power-driven cleaner may be made at home, says Popular Mechanics, by following these directions: First take a good pine board, 1 inch thick, 1 foot wide, and 3 feet long, and nail to each end a 1-foot length of 2-inch by 2-inch pine, as shown at A, Fig. 218. Next a ³⁄₄-inch board, 1 foot wide and about 1 foot, 3 inches long, should be fastened near the centre, and at right angles to the first board, as shown at B. Procure a tin pan measuring about 10 inches in diameter and 3 inches deep. This pan shown at C, must be fitted with two valves, which are the most important and difficult part of the work. Cut, from a smooth piece of pine, 1 inch thick, two discs, 5 inches in diameter, with a 3-inch hole in the centre of each. Obtain a sheet of packing rubber, ¹⁄₈ of an inch thick, and cut from it two discs, each 5 inches in diameter, and two 3¹⁄₂ inches in diameter. One of the discs of wood should be fastened to the back of the pan at the top, as shown at D, Fig. 219, with one of the 5-inch diameter rubber discs placed between the tin and the wood, and both secured to the tin by a row of small bolts around the outside edge of the wood. A hole, 3 inches in diameter, can now be cut through the tin and rubber, using the hole in the wood as a guide. Two discs with a diameter of 3¹⁄₄ inches should be cut from cigar box wood and fastened centrally on the 3¹⁄₂-inch rubber disc. One of the latter pieces should be fastened by its top edge to the top edge of the 5-inch disc of wood, as shown in E. This forms a flap valve, and great care should be taken to see that the rubber disc covers the opening all the way around when the valve is closed, so that it will be air-tight. A spring will be necessary to quicken the action of this valve. This is best made by fastening a narrow strip of wood across the valve opening on the inside of the pan, as shown at F, and attaching a rubber band to the centre of the valve and to this stick. This completes the outlet or exhaust valve. Another valve must now be made in the same manner, and fastened to the bottom of the pan on the inside, as shown. This is the inlet valve, and works in the opposite direction to the outlet valve just described.

Next procure a piece of leatherette about twelve inches in diameter, or large enough to cover the opening of the pan. This is to be used for the diaphragm. Cut a round hole about 8 inches in diameter in the upright piece B (Fig. 218), its centre about 7 inches from the top. From a piece of ¹⁄₂-inch pine, cut two discs 6 inches in diameter. Also secure a piece of hardwood H 1 inch by 1 foot 2 inches. The discs G should now be placed, one on each side of the leather diaphragm, exactly in the centre, and fastened to one end of the 1-foot 2-inch piece by means of a long screw. This piece H should exactly be in the centre of the diaphragm.

The pan can now be put in place. Set the diaphragm over the hole in the board B, the stick projecting through the hole. The pan is now placed over the diaphragm, and held by means of small bolts around the edge. The diaphragm between the wood and the tin acts as a gasket, and makes an air-tight joint.

Secure an air-tight tin about 8 inches in diameter and 12 inches high, and fasten it to the base board, as shown at J, Fig. 218. The cover of a coffee tin should now be soldered over the inlet valve, as shown at K, Fig. 219. Solder a hose connection in the centre of this cover, also one in the side of the tin, as shown at L, Fig. 218. Couple a short piece of hose M to these connections. The strainer S should be made of very strong and closely woven unbleached drill. Make it in the form of bag with a 1-inch hem at the top, and place it in the tin, as shown by the dotted line, the hem fitting closely over the inside edge of the tin. The cover of the tin is made from a flat pine board about one inch thick, and is held in place by two ¹⁄₄-inch rods fastened in the base board. These rods have thumb nuts on the top, which allow the cover to be readily removed or tightened down. It is best to place a rubber or leather gasket between the cover and the edge of the tin so as to make an air-tight joint.

An air-tight piece of garden hose can be used for the suction hose N, one end being fastened in the centre of the cover and the other to the brush or nozzle R, Fig. 218. It is best to buy this nozzle, as it would be rather expensive and unsatisfactory if home-made.

This machine may be driven by an electric motor of about 1¹⁄₄ horse-power, which should be placed in the position shown in Fig. 218. The end of the connecting rod H is fastened to a crank on the motor shaft, and allowed to have about a one and one half inch stroke. The motor is wired up with a switch, P, and it would be best to connect to a rheostat, to allow the regulation of speed best suited to the machine. This can readily be determined after the machine is started. If an electric motor is not available, a small water motor will do equally well; or it may even be run by hand, by means of a long lever, fulcrumed at P.

The machine is now ready for using. First, however, test it all over for leakage, as its success depends on its being perfectly air-tight. As the motor revolves, the rod H is drawn forward, bringing with it the diaphragm. This creates a partial vacuum in the pan C, which opens the inlet valve, sucking the air through the suction hose and strainer, the air carrying with it the dust and dirt. The refuse is left in the strainer bag while the air goes on through the connecting hose and pan and outlet valve into the atmosphere. After the article being cleaned has been gone over thoroughly, care being taken to hold the nozzle against the material, the cover may be removed and the bag emptied.

IV

MOTORS AND TYPE-WRITERS

MOTORS, GASOLENE AND STEAM—AUTOMOBILE FRAMES—THE MODERN TYPE-WRITER—DIRECTIONS FOR SECURING COPYRIGHTS.

There are two classes of heat engines in use; in one class the combustion takes place on the inside of the cylinder or generator, just as fire is applied to a tea-kettle, and the heat is transmitted by conduction through the metal walls to the part of machine doing the work. Motors and machines of this kind, are generally called "external combustion" engines, of which the steam engine is a prominent example.

Engines where the combustion takes place inside the machine itself, and acts directly on it, are engines of the second class, termed "internal combustion engines." The gasolene engine is of this type, and so are all gas and oil engines.

The principle of the motor-cycle engine, in its action, is similar to the regular automobile engine and the gas engine. All these are internal combustion or explosion engines; that is, their motive power is derived from the force exerted by the explosion of a gas while under compression, the compressed gas generally ignited by means of an electric spark. In the case of gasolene motors, the gas is obtained from the liquid gasolene, either by allowing air to be drawn through it or by spraying the spirit through a small hole, the latter being the method most generally used. A great quantity of air has to be mixed with the vapour before it will ignite. The amount that is required varies considerably, atmospheric conditions and the height above sea level causing variations in the demand. The action of the common gasolene engine is known as the "four-stroke-cycle," that is, there are four strokes of the piston for every impulse, one being a "power" stroke and the other three "duty" strokes, as it were. Each performs a certain operation that is necessary for the correct working of the engine. Some engines are worked on the "two-stroke-cycle" principle; in this case, there are only two strokes for each impulse. This type of engine has many disadvantages, and there are very few two-stroke engines in use for driving motor cycles.

The principle of the "four-stroke-cycle" is shown in Figs. 220 to 223. In Fig. 220 the piston A is just beginning the downward stroke, and the valve B is opened by the pressure of the atmosphere, or by mechanical means. The piston in descending causes a partial vacuum in the cylinder head or top C, which allows the atmospheric pressure on the surface of the gasolene in the carburetor to force some of the liquid through the spray hole, thence through the inlet-valve opening D, into the compression space of the engine cylinder. The suction of the piston does not bring in the explosive mixture of gas and air; it is the pressure of the atmosphere that causes the mixture of gas and air to rush into the cylinder. Just before the piston is at the extreme end of the downward or outward stroke, the inlet valve B is closed by the spring shown, and the piston begins the first upward or "compression" stroke with both the inlet valve B and the exhaust valve E closed. The charge is being compressed when the piston is on its upward stroke, as shown in Fig. 221. Speaking generally, soon after the piston is over what is known as the "dead centre," and is about the position shown in Fig. 222, an electric spark is made to jump across two points of the sparking plug F; this ignites the mixture of gas and air (which is at a pressure of about 80 lb. per sq. in.), and the explosion causes the piston to descend on the power stroke. Just before the piston reaches the bottom of the power stroke, the exhaust valve E, Fig. 223, opens, and remains open during the upward stroke. The momentum of the flywheels, etc., carries the piston upward, and thus forces out the burnt gases through the exhaust opening G, and from there to the silencer. Immediately the piston begins its next downward stroke, the inlet valve opens, fresh air is drawn in, and the cycle of operations is repeated as before. The illustrations show a magneto gear driven by the engine.

These engines when properly arranged are made to do service as marine motors, and are then installed either horizontally or vertically. A vertical engine has been shown on previous pages, but perhaps a little further explanation may not be amiss. Engines for boats are made with one cylinder or with more, and there are many considerations which make an engine of two or more cylinders particularly desirable. It is a self-evident fact that when the limit of size of a single-cylinder is reached, it is necessary to add other cylinders if greater power is desired. Even for moderate or small powers, there are many advantages. Among these may be noted the fact that with the proper arrangement of cylinders the impulses may be made to occur at shorter intervals than with a single-cylinder engine. Thus with a two-cylinder engine, the cylinder may be so arranged that the impulses will occur twice for every revolution instead of once, as in a single-cylinder. This gives a more even turning effect to the shaft, and consequently steadier running, and it also requires a less heavy fly-wheel. The vibration is much less, as one set of working parts may be made to travel upward while the other is travelling downward, thus neutralizing the throw of each and lessening the vibration.

In case of the disablement of one cylinder, there is the chance of getting home on the remaining ones. The weight, power for power, of the multiple-cylinder engine is less than that of the single-cylinder engine, as the weight of the fly-wheel and other working parts is less.

While for marine work, single-cylinder engines have been built as large as eight or ten horse-power, they are so large as to be rather cumbersome and the practice now is to build engines of more than six horse-power with two or more cylinders. There are several firms who are making double-cylinder engines as small as four horse-power, which both as to weight and reliability are much superior to those of a single-cylinder.

The original method of constructing a multiple engine, and one which is still used by some builders, is simply to use two or more single-cylinder engines coupled together. This is a cumbersome method and takes up a great amount of space. The simplest method which can be recommended is that shown in Fig. 224. It consists of two single-cylinders mounted on a common base of special design, bringing the cylinders much nearer together than when a coupling is fitted to connect two separate engines—as the shaft can be made in one piece. This particular engine is of the two port type, two vaporizers V-V being used. The gasolene enters at G and branches to each vaporizer. The pump is shown at P with the discharge at W, piped with a branch to each cylinder. The cooling water outlet is at O. The exhausts are connected to a common pipe with the outlet at E. The igniting gear for each cylinder is independent and on opposite ends. By means of the lever L, which is connected to both igniting gears, the time of ignition is regulated and kept the same on both cylinders. This allows multiple-cylinder engines to be built with very few extra parts, as the cylinders, ignition gear, etc., are the same as in the single-cylinder engine.

A view of a representative single-cylinder engine is shown at Fig. 225. The cam shaft is located at a and is driven by the gears which are shown just in the rear of the fly-wheel. At c are the cam and the roller, which actuates the exhaust valve. The cam consists of a collar with a flat projection or toe upon its surface; the roller rests just above the surface of the collar, and is forced upward when struck by the projection. The roller is inserted to lessen the friction by rolling instead of rubbing. The valve stem extends upward into the valve chamber, and is encircled by the coiled spring e; the stem is guided by the guide at g. The exhaust is at E; I is the pipe leading from the vaporizer V to the inlet port in the valve chest. The inlet valve is directly below the spring S and is inverted, being held in place by the spring. The dome-shaped cap containing the inlet valve is removable for access to both valves. The complete cover is also removable. It will be observed that this engine has an open frame very similar to that of a steam engine, giving free access to the crank-pin and main bearings; the latter are shown fitted with oil boxes b instead of the grease cups, as there is no pressure tending to force the oil out along the shaft as in the two-cycle type. This open base not only makes the bearings more accessible, but renders it easier to lubricate them and keep them cool. At H is the ignition gear. P is the cooling water pump, run by the eccentric e. The suction is piped to d and the pump discharges through the pipe k into the cylinder. The outlet for the cooling water is at O; N is the cylinder oil cup for oiling the bore of the cylinder. The compression cock R is for relieving the compression at starting. The coupling at X is for attaching the propeller shaft.

In this engine, the cylinder, base and bolting flange are one casting, the upper half of the main bearing being removable for the insertion of the shaft. The cover is bolted on separately.

AUTOMOBILE FRAMES

The chassis for the single-cylinder, eight horse-power motor machine shown herewith is built on the principle of most frames, of any make and is typical of the majority of light motor car chassis at present in use.

A diagrammatic plan of the eight horse-power, single-cylinder chassis is shown in the accompanying illustration (Fig. 226) in which, A indicates parts enclosed, taking the mixture of gasolene and air from the float-feed spray carburetor B, which has an automatic air regulator. The purpose of this last device is to dilute the mixture when the engine has a light load and is inclined to race; generally speaking, this regulator serves to proportion the ingredients of the explosive mixture to the requirements of the engine. Current O for the ignition of the explosive mixture (ignition occurs once for every two revolutions of the fly-wheel), is supplied by an accumulator and intensified by a high-tension coil. The products of combustion pass through the exhaust pipe C to the muffler D, from which they pass to the atmosphere through a series of fine holes. The starting handle E makes a simple connection with the end of the motor shaft F when required. G is the fly-wheel. The drive from the engine is through a universal joint H to the change-speed gear J, the latter consisting of two trains of toothed wheels, a big wheel on the primary shaft gearing with a small one on the secondary shaft to give a high speed, and vice versa. From the change-speed gear, the drive is through a shaft K, having a universal joint L at each end, to the bevel gearing above the differential gear of the live rear axle. Bevel gears and the differential gear are all contained in the casings M. Three brakes are fitted, one operated by pedal, working on a drum N secured to the propeller shaft, the others operated by the side lever and working on drums O O, secured to the rear wheels. The change-speed gear gives three speeds forward and a reverse; the frame is of pressed steel; the rod and wheels are of the artillery type and carry 700 mm. by 85 mm. pneumatic tires. The gasolene tank holds 4¹⁄₂ gallons, sufficient for 200 miles, and the lubricating oil tank holds 1 gallon, sufficient for 350 miles. Any beginner in motoring matters, who studies the diagram, will obtain a fair idea of the mechanism of the customary type of light car chassis.

A chassis, suitable for a 7¹⁄₂ horse-power quick-speed, two-cylinder motor, is shown in Fig. 227.

It is not necessary to enter fully into the details of construction after describing such a typical gear-driven car as that at Fig. 226.

The frame A is of tubular steel, there are four semi-elliptic springs, and the artillery wheels have 28-inch by 3-inch tires. The two-cylinder engine B is one casting, with a large waterway covered by an inspection plate C. The bore is 3.5 inches, stroke 4-inches, cylinder capacity 76.9 cubic inches, and the piston displacement is 92.300 cubic inches per minute. A governor automatically throttles the inlet when the motor attempts to race, but by means of a lever the governor can be cut out and the motor accelerated from its normal speed of 1,200 revolutions per minute. The balanced crank has but a single throw; the water circulation is assured by a motor-driven pump, and there is a belt-driven fan behind the radiator. The commutator is easily accessible, being mounted on a bevel shaft lying in a sloping position and passing through the side of the crank chamber. Ignition is high tension with wide contact, the wiring being enclosed in a neat wooden casing. The change-speed gear D gives three speeds and a reverse, and its main bearings are fitted with ring lubricators. A pressure sight feed lubricator on the dash-board has three outlets, one to the engine, another to the main clutch, and a third to the driving pinion on the end of the propeller shaft. The brakes are of the usual kind. In Fig. 227, E is the carburetor, F the inlet and G the exhaust pipes, H the exhaust muffler, J the brake pedal, K the clutch pedal, L the band-brake on the propeller shaft, and M the internal expanding brakes on the wheel hubs. A shield is arranged under the front of the car to protect the mechanism from mud and dust. The weight of the car unladen is about 1,414 pounds, the wheel base is 73¹⁄₂ inches, the track 46 inches, and the over-all dimensions are 111 inches by 60 inches. During a 600-mile trial this engine consumed 36 gallons, 6 pints of gasolene, this being at the rate of 1 gallon for every 16.9 car miles; .077 gallon was consumed every ten miles.

THE MODERN TYPE-WRITER

Every home of importance contains a writing machine of some kind, and these often require some little adjustment or "fixing." It is within the capacity of any bright boy to make these adjustments, or to do the little fixings, if he tries it earnestly.

The first marketable type-writer was introduced in the year 1875. No sooner had the type-writer acquired a commercial value, than the fire of inventive talent was awakened in Europe and America, and type-writer after type-writer appeared on the market—a few came to stay, but the many disappeared, either during the chrysalis or experimental stage, or shortly after it had been passed. Inventors and investors have learned that hasty innovations and untried experiments spell "failure" in the type-writer field, and only patient and careful study, backed by experience, tireless effort, and abundant resource, have a chance of success.

By the year 1888, there were six different kinds of machines in the market, to-day there are at least twenty, but the favourites seem to be, "The Remington," "Smith Premier," "The Underwood" and "The Oliver."

Modern type-writers may be defined as being tabulating, book recording, card indexing, and document writing machines. They are speedier and produce finer and more varied work than their predecessors.

The manner in which the type-writer performs its work is of the simplest. The type-writer may be considered as composed of three general parts, as follows:

The keyboard, by which the operation of the machine is directed.

The type mechanism, by which the desired letters are, one after the other, in any desired sequence, imprinted on the paper.

The carriage, which holds the paper in proper position for writing, and which, by its regular movements, provides for the spacing of letters and lines.

The Remington may be considered the pioneer of writing machines. In appearance the Remington No. 5 (introduced in 1888) is square, and strikes a novice as being somewhat complicated. It is only the multiplicity of parts, however, which creates this impression. The machine is not complex, the same parts being repeated over and over again. The action is simplicity itself. The machine is quite open on every side, so that its entire construction can easily be seen. There is a japanned iron frame enclosing and holding the working parts, consisting of a base, four upright posts, and a top plate. In front is a series of keys arranged in four banks, like the keys of an organ, each key representing the two characters, termed "upper" and "lower" case letters. These are connected with long light wooden levers, which, being depressed, communicate motion by means of a rod fastened to the lever of a type bar. At the end of each type bar is fixed the hard metal type representing the two characters. The type bars are arranged in a circle, therefore the point of percussion of the type on the paper is at a common centre. The inking is done by a ribbon, which travels automatically across the machine, winding and rewinding on and from spools.

The paper is inserted between two rollers; one of rubber, called the "paper cylinder," and the other of wood, called the "feed roll." The rollers are held together by two elastic india-rubber bands. As one revolves so does the other. The portion which holds these rollers is designated the "carriage." By a clever, yet simple piece of mechanism, this carriage is caused to travel, simultaneously with the return of the type or spacing bar, from right to left, the width of a letter at each movement across the machine. The carriage works on a sliding frame, and this sliding mechanism is controlled by two keys, which do not impress letters on the paper. These change the character of the printing keys, causing them to print capitals or small letters, numerals or other marks at will. Depress the key marked "upper case" and all the keys will print capitals; remove the finger and they all print small letters again. Moreover, the machine can be arranged to print capitals continuously by the mere raising of a lever, and quite independently of the "upper case" shift key.

To obtain an impression, the required key is struck lightly, and the type bar causes the type to strike against the ribbon, thus leaving an imprint on the paper held round the cylinder; the carriage moves automatically the width of the letter, and the operation is repeated until a word is completed. Then the "spacing bar" at the front of the machine is depressed at any point, thereby securing the requisite space between the words.

When the end of a line is reached, warning is given by the ringing of a bell, and then, by pulling out the lever at the right-hand side of the carriage and gently pressing to the right, the paper carriage is advanced into position to receive the next line. The distance between the lines and the width of the writing can be regulated. The paper carriage being hinged at the back allows of its being raised from the front by the hand, so that the line that has just been written can be inspected.

The motive power is imparted by an adjustable coiled spring, a thin leather strap being fastened to it and the carriage, and the uniform space is governed by two clutches working on a rack. This rack is fixed on a rocking shaft, and derives a swinging motion from a universal bar fixed beneath the light wooden key levers.

A small lever attached to the left of the carriage holds its movements under the control of the operator. Two scales are fixed on the machine, and these in conjunction with the pointer, permit of head-lines being centred, corrections made, etc.

In some machines, a special key and its accompanying mechanism is provided for each character or sign used—such are termed "complete" keyboard machines. In others, each key is made to represent the letters or signs—such are designated "single-shift" machines. Others, again, have two shift-keys, and each key represents not only a lower case (small) and an upper case (capital) letter, but a figure or other sign as well—such are known as "double-shift" machines.

The two classes of modern type-writers may be arranged into three groups, namely:

"Blind" writers, in which the writing remains hidden until exposed by manipulative effort of the operator. "Semi-visible" writers, which show only the last lines, or only expose the centre of the paper, hiding the writing at both ends of the line. "Visible" writers, which expose a character directly in front of the operator the instant it is imprinted; the character subsequently does not pass out of sight, by feeding behind a scale or bar, or other obstruction. This classification and grouping is for convenience only, and is in no way intended to denote superiority.