GOO 



Popjdar Science Monthly 



An Ingenious Attachment for a 

 Door-Lock 



AN attachment shown in the ac- 

 . rompanNin^ iUiistration of an ordi- 

 nary door-lock, permits of opening the 



A nail-and-spring attachment 

 to draw bolt of a common lock 



lock from the inside, wilhout the use of 

 a key. The lock is not changed from its 

 original form, and can be operated with 

 the key in the usual manner if desired. 

 An ordinary wire nail and a small 

 piece of clock-spring constitute the 

 necessary parts. The s]:)ring is attached 

 to the bottom of the lock in such 

 a way that when it is released the 

 bolt is withdrawn. The nail is inserted 

 through the bottom edge also so that its 

 upper end will lift the tumblers out of 

 I)osition and release the bolt. 



and west it would be easy for anyone to 

 go in these directions by simply following 

 the signs. Similarly, if one wished to 

 go, say, a hand's breadth to the right 

 or left of the beacons one could easily 

 do so. The largest stars in the hea\-ens 

 can be depended upon in the same way. 

 "If >()u put the front buttons of your 

 coat on the Xorlh Star or otiier direction 

 stars," writes this authorit\-, ">'our right 

 and left breasts gi\e you an angle of 

 45 degrees from the star and your 

 shoulders a right angle. Also,' it is only 

 a matter of a little practice 

 to be able to measure 15 

 degrees of horizon with your 

 hand, so you can get any 

 number of degrees to the right 

 or left of your direction stars, 

 and after a little practice it 

 l)ecomes second nature to 

 recognize the points of the 

 compass at sight, and you 

 accjuire the same sense of 

 direction as Bushmen, Arabs, 

 and [)cople who li\e far away from 

 ci\ilization. 



"The North Star, Altair and Vega are 

 all-sut¥icient night-guides during the 

 spring and summer, and for autumn and 

 winter the North Star, the sword and 

 bell of Orion, Procyon and Regulus." 



Finding Your Bearings at Night 

 Without a Compass 



AN Englisii sur\i\-or of the South 

 . African War who was often sent 

 on long-distance night reconnoissance 

 has worked out a system whereby any- 

 one can be right at iiome in the dark 

 witiioul compass (jr other instrument to 

 aid the sense <jf direction. Hi' worked 

 out the exact mo\emeiit anil direction 

 <if the largest and most easily <listin- 

 guished lights in llie heavens so that the 

 least scientific eye can recognize these 

 signs by sight and the whole dome of the 

 heavens becomes a vast compass. 



If there were fire balloons or beacons 

 placed in the heavens north, east, south 



To Make a Sanitary Cap for the 

 Milk Bottle 



TAKE a piece of flat spring steel, 

 such as a piece of corset stay or 

 clock-spring, if not too hca\y, 14 •"• 

 wide, tile length to be determined b\' the 

 size of the milk-bottle neck o\er which it 

 fits. ProbabK' 4'.. in. will be about the 

 right length. Benil as shown in the 

 illustration, making a sjjring clip to con- 

 form to the lop of the bottle. Drill or 

 pimch a hole 3-32 in. in diameter in the 

 center of the clip. Cut out a disk of 

 tr.uisparent celluloid, such as is u.sed in 

 automobile cintains, of tln> right diame- 

 ter to drop easily into the neck of the 

 bottle but large enough so that it lodges 

 on the ledge, in the neck of the bottle 

 upon which the original j)aper cap rested. 

 With a i)unch or sharp-pointed knife, 

 make three circular holes in this disk, 

 one in the center t,-t,2 in. in diameter, 

 another one ' ,s in. in diameter 7-I6 in. 



