The principle of this is as follows. A wire is stretched tightly between two points, for a small suspended carriage to run on. One end of the cable can be raised or lowered to give a slope in either direction. A person at that end is therefore able to control the movements of the carriage.
– Carriage for Model Cableway.
Boxes – and the string attached to this, the kite will probably fly higher, but there is more risk of breaking the string in gusty weather.
A few words about the string, on which freedom from accidents largely depends. Itshould, if possible, be string sold specially for the purpose by the games department of a big store. A winder should be made for the string. The simplest form is a board 15-inches long, with a deep V-cut in each end.
The edges of the Vs are chamfered off to avoid fraying the string. Winding will be quicker if a piece of I inch rod is nailed across the centre of the board, 6 inches projecting on one side, for the left hand 10 depend upon circumstances; but one may suggest 100 feet as a comfortable limit. The longer the wire is, the greater must the height-range at the working end be. Three feet should be allowed for every 50 feet of run. This will allow a maximum grade of 1 ½ in 60 in either direction, which ought to be steep enough for easily-running wheels.
The Carriage. It is 8½ inches long over all, 3 inches high, and 3 ½ inches wide. But these dimensions, as well as other details, may be modified to suit the choice and patience of the maker. A point to be noted, however, is that weight should be kept down te the minimum consistent with due strength, as overloading the wire will cause a sag that may hinder running. The thinnest plywood, or stout veneer, may be used for the woodwork, and celluloid for glazing the windows.
The making of the hangers demands special care. One arm does not touch the roof, as a gap must be left for getting the wire to the under side of the wheel. When the wire is in place, the free end of the hanger is held down by the little revolving block A, which had been turned out of the way to admit the wire.
The hangers are fashioned out of flat brass strips, ½ inch or f inch wide, and inch thick. If the brass is stubborn, it should be softened by heating to a dull red and plunging into cold water. Cut off the length after the bends have been made.
The ends of a wheel spindle must be stepped, as shown, by turning in a lathe or careful filing with a file having one non-cutting edge. Filing will require patience, but is worth some of that virtue, as nicely-made spindles mean easy motion.
The two wheels must be perfectly in line, if the carriage is to run with a minimum of friction.
Walls and tree-trunks make good anchorages. At its fixed-height end the wire passes over a pulley and is attached to a weight – a few bricks, a bag filled with earth, or a can filled with water – heavy enough to keep it taut. The other anchorage is a vertical rod of 2-inch by -inch wood, straight and carefully planed and sandpapered. The lower end is sunk into the ground, the top end anchored.
Slots for pulleys are made near top and bottom for a cord to run over. The ends of the cord are made fast to the ends of a sliding traveller B , to which the wire is attached. By hauling on the slack of the cord at the back, the traveller is raised or lowered at will. The rod should be kept well greased.
To prevent the carriage being damaged by collision with the far end support, a couple of pliant rods should be fixed, one on each side of the wire, about a foot away from the pulley, and reaching a few inches above it. When struck, their tops will bend and act as buffers.
Gramophone, Wonder Discs for the. The careful use of your compasses and a little patience will provide you with the three discs shown in Figs. 1, 2 and 3 to amuse yourself and your friends. They are intended to be placed on the table of a gramophone and made to revolve at a steady speed; or, if no gramophone is 275 available, they may be mounted on a lead pencil or a suitable piece of wood, sharpened at both ends and supported upright on the table while it is rotated by the fingers. The discs are 10 inches across, and should be of stout cardboard, white on one side. Cutting-out should be left till the design is finished.
One is painted blue and the other red. When the disc is revolved the two large circles appear to run independently round the small one.
Our next card is rather more elaborate. Two centres, A and B, half an inch apart, are marked. With B as centre, draw a small circle; then, with A as centre, a larger circle enclosing the first. And so on, using the centres alternately. When the disc is spun about centre B, it seems to the eye that the coloured parts are separate discs alternating with white discs.
Here we have a wavy line, made up of parts of six circles, which, when the disc is turned slowly, wriggles in a most surprising manner, as if it were made of jelly. The background should in this case be black, and the line brightly coloured.
Since the drawing of the card is not so straightforward as that of the other two, a separate diagram of instruction is given. First draw the large circle A, and, without altering the compasses, step round the circumference with them. If this is done carefully the circumference will be divided into six equal parts. Through the centre and the points thus obtained draw six lines aaa, bbb.
From points on aaa draw parts of three circles BBB, of half the diameter of A. Then from points on bbb, outside A, draw parts of circles ccc, of the same diameter as BBB, and running into them, DDD are then drawn from the same centres as BBB, and EEE from the same centres as jaBHraBBBjBfcj ceo. The joining-lip of (lie various area must be done neatly to produce a good effect.
So far we have worked in pencil. Ink is then used on those parts of the circles needed to enclose the portion which is dotted in the diagram; and, finally, all the rest of the card is coated with Indian ink, and, when this is dry, the band is coloured.
In the centre of each card must be made a hole for the axis of the gramophone table to pass through; or to allow the card to be mounted otherwise.
most entertaining manner.
Kaleidoscope, A Home-made. The and with thoir many reflections form ever- ordinary toy kaleidoscopo is a metal changing patterns.
At one end is an eyepiece, and at the other an object-box containing a number of pieces of coloured glass. Wben the tube is revolved the pieces arrange the colours in different ways,
Its base is a long box on end, with the upper end removed. Insido it are a number of rollers, two of them almost flush with the top, round which runs an endless belt of paper or other material, carrying on the outer side the designs to be viewed. Two mirrors are arranged vertically on the top of the box, in contact at one edge, mirrors, the figures on it seem to be coming out of the point where the mirrors meet and to spread in all directions. If, on the other hand, it moves towards the and at right angles to one another. The belt is moved mechanically in the direction of a line bisecting the angle between the mirrors.
If the belt moves away from the mirrors, the figures contract as they approach, and seem to disappear at the point of junction.
The apparatus is something more than a mere toy, though it gives much enter- tainment to children; and it can be made quite easily. The dimensions given need not be adhered to strictly, though the proportions should be observed.
The mirrors are 6 inches square, and not more than ½ inch thick. The silvered side is varnished, and covered, while Bticky, with strong paper, which will protect the film. The mirrors are backed by two pieces of -inch oak or walnut bevelled off to meet at 45° and glued together. Along the top and outside edge of each are glued strips of wood, projecting beyond the thickness of the mirrors, and blackened at the edges which touch the glass. The mirrors should be arranged so as not to overlap, but merely to touch along the edges, enclosing a tiny square at the angle. They are kept in position by narrow strips of black gummed paper, adhering partly to the frame and partly to the mirrors.
The box is of J-inch wood, and its parts are screwed together. The plan view shows two shelves, S K D s, P c L p, attached to the outside of the box on brackets, and flush with its top edges. These help to support the mirrors, and an aluminium plate, GKDCLNYG, extending under the edges of the mirrors and having a semi-circular-ended opening, G Y N, in it to display the band of designs.
The rollers, E F, are ½ inch or 1 inch in diameter and turn on pins passing through the sides of the box, so placed that the band just clears the under side of the aluminium plate, R and R are two metal or wood pulleys, encircled by rubber umbrella rings and fixed to a spindle turned by a handle. The spindle rotates in plates on the outside of the box; and the rings press hard enough against the roller to turn it. M T o are rollers similar to E F. The space w v B o is for an electric motor, which may be fitted if desired, to drive R R through a clock-work train, connected with their spindle by a belt outside the box.
The band is about 4$ inches wide, and kept in its proper course by strips glued to the sides of the box between the rollers. If extra rollers cd ef g be fitted, the band can be of great length, as is indicated by the dotted lines.
The designs should be not more than ½ inch apart. Begin with very simple ones – circles, ellipses, spirals, 8s, Ss etc., and proceed to more ambitious outlines, such as simple drawings of animals, birds and insects, and tattooed figures. The colouring must be as vivid as possible.