The Alarm and Wiring Diagram
Should the temperature fall during the night, the mercury will contract, the float descend and the circuit close, so that the bell will ring. The adjustable lever allows setting the alarm for various differences of temperature.—Contributed by Klyce Fuzzelle, Rogers, Ark.
Paper Smoother and Penwiper
A convenient paper smoother and penwiper can be easily made as follows: Procure a common celluloid harness ring, A, about 1-1/2 in. in diameter and fasten a penwiper, B, to it. The wiper is made of arts-crafts leather, doubled and filled with pieces of chamois. They are held in place with a ribbon or cord tied as shown. The roughened paper caused by erasing can be easily smoothed with the ring.—Contributed by G. H. Holter, Jasper, Minn.
Stereoscopic Pictures with an Ordinary Camera
Make a small table as wide as the camera is long and 3 in. longer than the camera is wide. Sink a screw nut in the center of the under side to engage the regular tripod screw. Fasten a double or two-way spirit level on the front left-hand corner. Nail strips on both ends and on the rear side, to form a shallow box with three sides. The illustration shows the construction quite plainly. This device was used by a correspondent of Camera Craft as follows: The table was fastened to the tripod and carefully leveled. The camera is placed at one side, bringing the back snugly into the corner on that side. Make the exposure, change the film, slide the camera over to the other side and make another exposure. The table being 3 in. longer than the camera is wide, the lens will be moved exactly 3 in. when the camera is moved over to the other side. Three inches is the separation of the lenses in stereoscopic cameras and the negatives made as above will be the same.
Table on Tripod for Camera