Popular Science Monthly
���Moving Targets for a Home Shooting Gallery
THE moving targets, now so common in shooting galleries, are entirely out of the question for home practice, owing to the cost of the machinery and its bulky nature; however, the same results can be obtained with the device illustrated, which is not expensive or difficult to construct. It con- sists of a board placed on a slant on tw-^o posts. On this board the moving objects roll. These are made of plaster formed in tin-can covers. To prevent the disks from rolling off the board, strips are nailed on as shown to make a groove for them. At both the upper and lower end, facing boards are fastened so that the marksman cannot see the disks until they start rolling.
���Details of the moving target-stand and the trap used for releasing one disk at a time
A number of disks are set in the groove at the upper end and one disk is released at a time by a trigger operated with a string. The speed of the rolling disks is governed by the slope. — G. P. Lehmann.
��An Expanding Bolt for a Bottle Stopper
AN expanding bottle stopper can be ,. made with an ordinary rubber or a jcork stopper and a bolt of the usual iexpansion type. The threaded end of an iron screw is set in a mold and lead or
��babbitt metal run in about it. The mold is made to cast a conical slug having threaded sides. The opposite end of the screw is forced through a cork or rubber stop- per and bent into a circle, as in- dicated in the drawing. When a cork is too small to fit a bottle, the screw is turned and the expansion slug forces out the sides. The cork is re- moved by unscrewing the slug. Such a device can be used only on bottles which do not contain acids; for the acids would destroy the metal screw.
���Conical screw to expand bottle stopper
��Sponsons for Motor Boat or Motor Canoe
EVERY one who has run a motor canoe or boat against a head wind must have noticed how the spray will come aboard and make things unpleasant. The following device is one I have used for a number of years with great success, and it is also of great value for fenders when running along- side a pier or landing stage. Procure from a garage two old inner tubes both the same length and size. Cut them at one point and cement the ends, or, better still, have them vulcanized. I cemented mine but I found that it was necessary to put wooden clamps on each end to keep them from coming apart.
Make two snug canvas covers of 8 oz. duck. These can be easily made on the sewing machine. With a little manipula- tion the tubes can be drawn through the covers. Make a hole in the cover for the valve. The tubes are then blown up and either lashed or strapped to the gunnel of the canoe starting from the bow. Besides warding off the spray they will also help considerably in case of an upset as the air they contain would keep the boat or canoe from sinking. — B. E. Dobree.