THE HANDIWORK OF SOME CLEVER SCHOOL-BOYS.
By J. Abdon Donnegan.
The Fair of the American Institute held annually in New York, is chiefly a display from the various American trades showing improvement and advancement; here designers and inventors also present many novelties and useful inventions for public criticism and judgment.
One feature of the Fair of 1885 that attracted much attention and comment, was the novel and unique display of mechanical models designed and constructed by the boys of the third grade in Grammar-School, No. 57, one of the public schools of New York City. The work exhibited by these boys is peculiarly interesting and suggestive, and is an indication of what observant, thoughtful, and intelligent boys can devise and do when their tastes and natural inclinations are developed.
The boys' models were made at home, after class-hours, and on odd holidays during the six months previous to exhibition, and were primarily intended to illustrate the principles of the six mechanical powers,—the inclined plane, the lever, the wedge, the pulley, the wheel and axle, and the screw. When the American Institute Fair opened, an inclined railway, with its platform and cars; a miniature guillotine, with ready knife; a dumb-waiter in full working order; a derrick prepared to raise many weights; a pile-driver with its automatically dropped weight, the sound of which never failed to attract attention,—all these, with other models, occupied a space in Machinery Hall.
During the morning hours, curtains screened the models; in the afternoon the youthful exhibitors arrived and took special delight in showing the working of their designs. The pleasant hours spent there, the praise of visitors, and the recognition and commendation accorded by the press will be long remembered by the boys. At the closing of the Fair, the exhibit was awarded the Medal of Merit.
The illustrations on pages 548 and 550 show the models exhibited. Figure 1 represents an alcoholic furnace, illustrating the expansion of a brass rod by heat. A cylinder of tin, fifteen inches in height and five in diameter, is hinged to a base of wood and arranged so as to tilt to the left. A lever fifteen inches long opens and closes a damper; this lever (an umbrella rod) is inserted in a pivoted rod of wood two inches long, supported in a square frame made of an inch strip of tin bent twice at right angles and soldered to the cylinder.
A brass banner rod, seven inches long, also connects with this rod and, passing through an inch opening, is supported in the flame of an alcohol lamp and fastened on the opposite side by a tiny brass knob screwed on the protruding thread of the rod. A small pulley and weight steadies the motion of the lever.
The heat of the alcohol flame causes the brass rod to lengthen, and this in turn moves the lever which opens the damper; and the degree of expansion is indicated on a paper scale by a straw pointer attached to the rod of the damper. A coating of copper bronze was given to the cylinder. This model was made in part by Winfred C. Rhoades.
Figure 2 shows a forge made by William E. Tappae. A hand-bellows is mounted on a wooden base about ten by twenty-four inches in size, and is worked by a lever handle supported in a frame twenty-six inches in height. The bellows consists of two boards connected by flexible leather tacked to the edges. The upper board is stationary, and an inch central opening is covered on the inside by a two-inch flap of chamois fastened at one point, forming a valve.
As the handle is pushed up, the air rushes in, and when pulled down, the valve closes and the compressed air is forced through the metal nozzle to the glowing coals. The carved-wood anvil was stained black and the other parts were painted a bright vermilion.
Figure 3 explains one way of connecting levers, and their uses as a mechanical aid. The base is four by fifteen inches in size, and the pillars are respectively six and ten inches in height, and are firmly mortised and glued into the base. The upper lever is eighteen inches in length, and connects with the ten-inch lower lever.
The lead weights, sliding on the narrow edges of the levers, balance each other, and show how the heavy wagon of coal is balanced in the office by the weight on the scale-beam.
A wedge made of oak ten inches in height and five inches in width is indicated by Figure 4.
Figure 5 represents a diminutive pile-driver, twenty-eight inches in length, showing the plan and action of a large machine.
SIMPLE MECHANICAL APPARATUS MADE BY BOYS UNDER 14 YEARS OF AGE. DRAWN BY J. ABDON DONNEGAN.
The two-pound drop-hammer falls a distance of twenty-two inches in the grooves of the vertical posts which are mortised and glued into the base, as are also the oblique braces to which are attached the bobbin, or axle, and crank, on which the cord is wound that raises the hammer. This hammer is a flat piece of iron having two pieces of wood, each four by two and one-half inches in size, cemented to it. A wire hook is attached just above, and the extended arm of the hook as the weight nears the top, meets a projecting pin, and slips the weight from the cord.
Figure 6 is the model of a wood-press useful in pressing flowers for an herbarium. The base and pressure board are each ten inches square, the supports eight inches in height, and a wooden screw connected with the upper board turns in the cross-piece. This and the models shown in the drawings numbered 3, 5, and 10 were made by Harry Stœcker.
Figure 7 represents the model of an inclined railway constructed upon the plan of the inclined railway actually in use between Hoboken and Jersey City Heights. A board forty-five inches in length and ten inches in width connects the terminal platforms of this model. The upper platform rests on a support thirty-three inches in height; to this support is attached an axle turned by a crank, on which are wound the reversed cords which connect with the ascending and descending platforms. These platforms are mounted on rollers and the cars while in motion are kept in a horizontal position. This model was constructed by Everett L. Thompson.
The same boy constructed also the model shown in Figure 8—a dumb-waiter with original arrangement of cords and pulleys. The frame is thirty-six inches in height, eleven inches in width, and five inches in depth. Inside, a carrier with shelves is raised by a cord passing over four pulleys, the action of which may be seen through glass slips fitted in grooves. To the end of a cord is attached a weight which balances the weight of the carrier and contents. The frame-work was stained a dark mahogany color, oiled and varnished.
Figure 9 represents a miniature guillotine as made by David W. Benedict. It was copied after one brought from France and exhibited at a well-known museum in New York City.
The frame is twenty-two inches in height, and the block to which is fastened the tin blade, falls through the grooves in the posts to the rest upon which lies the head of the criminal. The cord raising the block runs over the pulleys, and is wound on the cleat when not in use. A box beneath receives the head of the imaginary victim as it falls. The machine with the exception of the blade was painted in bright vermilion and varnished.
Figure 10 shows a small derrick constructed after a sketch of one used in the erection of the Madison Avenue bridge across the Harlem River. A mast of maple twenty-seven inches in length is mortised into an oak base, ten by twelve inches in size. A projecting arm, or jib, is fastened to the mast by a clasp of heavy tin. A cord and pulley keep the jib at a proper angle with the mast. The weight is hooked to a double pulley connected with the single pulley near the end of the jib; the cord, passing over a wheel in the mast and then passing downward, is wound upon the axle by turning the crank; a toothed wheel and ratchet stops the weight at the desired height. Neater pulleys than could be purchased were made by joining two wooden buttons and placing them in a whittled frame bound with piano-wire. The mast and jib were painted a dark blue and the base was polished and varnished.
Figure 11 shows a model of a foundry crane, much admired for its accuracy of design and finish. It was made by George Chase, of seasoned maple with iron and brass connections. A swinging jib is pivoted at the top to a brass plate screwed to the cross-piece of the frame, and turns on a steel pin fitted to a plate on the base. A carriage travels along the jib, being kept at the required distance by a cord passing over a wheel at the end of the jib. A cord attached to the carriage passes over a pulley connected with the weight, and also over the wheel of the carriage, to the wheel directing it to the axle, which is turned by a cog-wheel and pinion taken from an old clock.
The carrier of the elevator shown in Figure 12 is hoisted by a cord passing over a small iron pulley fixed to the cross-beam of the grooved posts, and thence to the spool, or axle turned by a crank.
A clock-spring attached to a square wooden rosette is shown by Figure 13.
Figure 14 represents a pump improvised by John B. Cartwright from an old mincing-machine.
A handle turns a series of spur-wheels, which in turn give a rapid motion to a twelve-inch walking-beam. To one end of this walking-beam is attached a piston-rod, with a soft rubber disk working in a brass cylinder five inches long and three and a half inches in diameter. Iron fittings, including two brass valves, one on each side, connect with the cylinder; an air-chamber is formed with a fitting and cap. The suction caused by the upward motion of the piston will draw water from a pail or cup through a rubber tube connected with the end fitting of the right-hand valve, then through the valve to the cylinder; the downward motion of the piston causes the water to pass through the left-hand valve to the receiving vessel, and the air-chamber tends to make the flow regular. Parts of the machine were painted blue and striped with gold bronze.
SIMPLE MECHANICAL APPARATUS MADE BY BOYS UNDER FOURTEEN YEARS OF AGE.—DRAWN BY J. ABDON DONNEGAN.
By the removal of one pane of glass from a window facing south, the apparatus shown in Figure 15 may be used, like a magic lantern, to project transparencies, in a darkened room.
A pine board, fourteen inches square and one inch in thickness, has an opening in the middle to receive a wooden frame seven inches square, holding a six-inch cosmorama lens, having a focus of eighteen inches. A three-inch plano-convex lens having a focus of nine inches, mounted in a wooden frame, slides along a slit or opening in a board hinged to the inner side of the board which is cleated to the window.
A plate-glass mirror, eight by fifteen inches in size, is secured to a board hinged to a wooden rod, which can be turned from the inside, and is raised and lowered by a cord winding on a key. The mirror is lowered and inclined until the sunlight is reflected through the lenses, and then a circle of intense light, from ten to fifteen feet in diameter appears on the wall or screen. Both lenses will not cost more than two dollars, and the apparatus will most impressively illustrate experiments in light and sound.
An easily made electric lamp is shown by Figure 16. An Argand chimney is fastened to a wooden base, with the cement known as "Stratena," and partly filled with water. A cork coated with paraffine is placed inside the chimney, and a rod of carbon twelve inches long and one-sixteenth of an inch in thickness being inserted in the cork, the upward pressure of the water on the cork causes the end of the carbon rod to come in slight contact with a thick rod of carbon which is fastened obliquely to a square piece of wood, cemented near the top of the chimney. A brass chip fastened to the wood keeps the thin rod of carbon in position, and when two copper wires connect the carbons with six to ten jars of a bichromate battery, a light appears where the two carbons meet. As the thin rod wastes away, the cork rises and keeps the end of the rod almost in contact with the other carbon point.
An ambition to creditably make a mechanical contrivance or apparatus is noticeably characteristic of many boys. The construction of an aquarium, a sailboat, or a telescope, or some similar object, is of absorbing interest to such lads; and the making of the electrical apparatus of straws, sealing-wax, etcetera, once described by Professor Tyndall, has merely tasked the ingenuity of thinking boys to improve upon the apparatus.
Many educators maintain that manual training of a pleasant character, adapted to the age of the pupils, should form an essential element in the education of boys and girls, and should be placed on a par with the regular studies. There is no doubt that such instruction stimulates ambition and tends to develop taste, skill, and natural invention. At the same time an insight into mechanical occupations, with some practical experience in the handling of tools, may assist a boy in choosing a calling suited to his taste, and better prepare him to enter some practical industry, if his choice should incline toward such an occupation.
A few years ago, manual training in modeling, wood-carving, carpentry, forge-work, and other branches, was introduced into a technical course in the College of the City of New York, in East Twenty-third street. To-day it is one of the most interesting features of the College work, and is highly appreciated by the students. Private schools in this city, as also some of the public and private schools of Boston and Philadelphia, have introduced the workshop into their methods of instruction, and devote a few hours in each week to practical and manual labor.
The models illustrated in this article represent many well spent and helpful hours of recreation, and other boys may find pleasure and profit in making similar use of their leisure time and their powers of handicraft.