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 



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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. 



