132 



Popular Science Monthly 



A phonograph behind some convenient 

 bushes took the place of an orchestra. 

 Another clump of trees served to show 

 where the fisherman's hut was supposed 

 to stand. Such was the stage and its 

 machinery. The audience, seated ancient 

 fashion upon the hillside, enjoyed what was 

 probably as lifelike a presentation of fairy- 

 land as could be produced by human 

 beings. — Shirley L. Seifert. 



An Experiment in Optics Using 

 Heated Graphite 



AN interesting experiment in optics may 

 . be performed in the following manner: 

 Take a bit of hard graphite, such as a lead 

 pencil, and hold it in the tip of a candle 

 flame until it is completely covered with 

 soot. It will then appear black in the air, 

 but lay it in some water, completely 

 covering the lead part, and it will appear 

 like silver. The explanation of this phe- 

 nomenon is that the water is unable to 

 touch the object, due to surface tension and 

 lack of cohesion. The water then acts 

 like an unsilvered sheet of darkened glass, 

 reflecting the light. — Thomas W. Benson. 



Small Hand Drill Made from 

 a Cheap Watch 



IN doing some very fine repair work it 

 was necessary to use a smaller drill 

 than could be used in a breast drill without 



Two small clock gears used in the frame of 

 a cheap watch to drive a small drill point 



breaking. To accomplish the drilling of 

 very small holes I made a drill driver of 

 an old dollar watch and some parts taken 



from a discarded alarm clock. All the 

 wheels, ring and winding stem of the 

 watch were removed, keeping the frame 

 intact, as shown at A. The drill chuck 

 and drive shaft B were made from the 

 ring bolt taken from the alarm clock. The 

 nut C was cut on the dotted line and the 

 knurled part used for tightening the slotted 

 end of the bolt on the drill shank. Of 

 course it is necessary to drill a hole and 

 saw a slot across it in the threaded end of 

 the bolt for the chuck jaws. 



Two suitable gears were taken from the 

 clock movement and arranged as shown 

 in the watch frame. The bolt is filed or 

 turned down to the dotted lines D to fit 

 into the hole in the watch stem. A crank 

 is attached to the driving shaft as at E. 

 The handle for the crank is made from 

 one of the feet on the alarm clock, the 

 arm being cut from a piece of sheet metal. 



A Snap-Fastener for a Small 

 Cupboard Door 



AN efficient fastener for small cupboard 

 l doors can be quickly and easily made 

 from a brass-headed tack, a piece of soft 

 rubber, a small piece of tin and a few small 

 nails. Bore a hole in the edge of the door 

 % in. in diameter and 

 at least Y2 in. deep at 

 the location for the 

 fastener. Cut a piece 

 of the soft rubber to a 

 shape and size that will 

 entirely fill the hole 

 and drive the brass- 

 headed tack into the 

 rubber as shown in 

 section drawing, taking 

 care, however, that the 

 tack is not long enough 

 to enter the wood at 

 the bottom of the hole. 



Cut a piece of tin or 

 other sheet metal about 

 % in. square and form a depression in its 

 center that will be just the size and shape of 

 the head of the brass tack. Punch a small 

 hole in each corner for nails. 



In order to find the exact spot where the 

 plate should be placed, open and shut the 

 door a few times, causing the tack head to 

 draw a mark on the door frame. At the 

 extreme end of this mark make a shallow 

 depression. Place the convex surface of 

 the plate in this depression, tack it into 

 place and it is ready for use. 



Snap-fastener 

 placed on a cup- 

 board door 



