Page:Popular Science Monthly Volume 91.djvu/648

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��Popular Science Monthly

��useless unless two cars are placed in the shaft. A two-car system is ideal where the lift is carried to an upper floor with openings on both floors. The upper box has guides of a special design, as shown,


to allow the lower cage ropes to pass. The \ winches are set at right angles to permit each lift to be worked inde- pendently. If the upper lift alone is to be used the lower cage may be kept down. The upper winch should be high enough to permit its use when the lower cage is down, as the accompanying drawing shows. Frequently, because of small capacity, difficulty of operation and inaccessibility, it is as easy to carry firewood upstairs in the old-fashioned way. But this lift has a large capacity and its open side not only offers its contents readily, but provides a means of cleaning. While it is often possi- ble to build a lift beneath a stairway, con- venience should not be sacrificed to save a few feet of floor or bookcase space. There should be some way of reaching the pulley- block at the top of the shaft to oil the pulleys. — Edward R. Smith.


An extra car for the dumb waiter shaft

��Improving Your Piano by Moistening the Air in the Room

A RELIABLE piano tuner says that pianos are often injured because they become too dry. Keep a growing plant in the room with the piano and see how much more water it will require than the plants in any other room. A large vase with a wet sponge kept near the piano will supply moisture. — C. A. Wolfe.

��A Simple Camera Attachment for Photographic Enlarging

ANYONE owning an ordinary folding . pocket camera with adjustable focus can easily make and use this enlarging out- fit. The sketch shows a longitudinal sec- tion and gives an idea of the general arrangement. The box is fitted up with an electric lamp, socket and reflector. The other end has a square hole the size of the opening in the rear of the camera cut into it. Two clamp pieces are cut out and fastened to the box as shown, so that the camera is held firmly to the opening in the front of the box. A slot is recessed over the hole so that a sheet of orange-colored glass will slide in it and cover the square hole. The base-piece is extended several feet beyond the camera and is slotted its entire length. A sliding screen of some light- weight material is made and fastened in the slot in the base with a thumb-screw, as shown. A sheet of fine white tracing paper should be fastened over the inside of the hole in the box so as to diffuse the light from the reflector and prevent unevenness of light distribution.

Place the film or plate in the opening in the back of the camera and turn on the light. Have the sheet of orange glass in the groove provided for it back of the camera. Darken the room and pin a sheet of bromide or other enlarging paper on the sliding screen with thumbtacks. The orange light coming through the lens will furnish sufficient illumination for this. Now focus the image on the paper by moving the camera bellows in or out and by moving the screen to and from the

���Enlarging pictures with an ordinary camera placed on a box inclosing an electric light

camera until the correct focus is obtained. Now slide out the orange glass and expose the paper for the required time, after which replace the glass to stop exposure. Develop the paper in a red or orange light only. A sixteen candlepower mazda light will oper- ate the apparatus. — B. Francis Dashiell.

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