Popular Science Monthly
���If a burglar tries to "crack" this safe he will b e blown u p by his own nitroglycerine
Foiling the Safe Blower
GROOVES are made in the upper edge of the safe door, so that in case nitro-glycerin is poured into the crack of the door, it will flow through these grooves to an element which may be destroyed without injuring the rest of the safe. Upon disintegrating, this element sets free a spring motor mech- anism which operates a rotating hammer. The hammer strikes a succession of blows upon a percussion pin. Thus the nitro-glycerin is exploded prematurely and the successful blowing of the safe is prevented.
This Can-opener Cannot Slip
ANEW can opener, which locks fast so it cannot slip and cut the hand, has been placed on the market. It also opens round or square cans, and removes
���111
metal caps from bottles and tins. The tool is prevented from slipping by an adjustable lock, which can be moved back and forth and made to fit any size can. This lock is composed of a cutting edge fastened to a movable clip. The cutter is adjusted for the can to be opened. It operates on a central pivot as in one of the old-fashioned can openers.
Square cans are opened by this tool with a cutting knife of the other type, also arranged so that it cannot slip. A hooking device is attached for removing metal capping corks for bottles.
A Feed Hopper for Chickens.
A FEED hopper for chickens can easily be made by sawing the sides of a laundry soap box as indi-
���This new can opener does not cut fingers. It opens bottles as well as cans
��The slanting front of this hopper is suf- ficient to keep the supply of grain in the screened feed box constant
cated. A lid is fastened on the top by hinges, and the feed is poured in at the top. The front slants, which keeps the feed always sliding down as it is taken out of the opening. The open- ing is covered with chicken wire to keep the fowls from stepping into the feed and fouling it. The dotted lines show the original construction of the box.
�� �
