Popular Science Movthhf 



203 



can be done at four ihoiisaiid feet, in 

 which case the width of the field is al)out 

 two thousand, four hunchx'd leel. 



Suppose a scout is given orders to 

 photograph the entire territory occupied 

 by the enemy. He reguhites his camera, 

 soars aloft, and when over the enemy's 

 trenches at an altitude of two thousand 

 feet, for instance, turns a lever which 

 releases a propeller in front of a gear box, 

 which, in turn, starts the camera mechan- 

 ism in motion. Instantly he obtains a 

 continuous photograph of the earth's 

 surface one thousand, two hundred feet 

 wide. 



Should he desire to get more useful 

 infoniialion by continuing his flight at a 

 higher altitude, he stops the camera 

 mechanism and ascends to twice the 

 height. There he makes a readjustment 

 of the apparatus and continues his 

 flight, taking a continuous photograph 

 meantime. Mile after mile he continues, 

 until, if he so wishes, he can obtain a 

 photographic record of one himdred and 

 thirty miles of the enemy's territory. 



Briefly, the camera consists of a camera 

 bo.x cc)ntaining two rollers round which 

 the film is carried. The film has a 

 scries of perforations along one edge, and 

 a toothed stop is provided to engage 

 with these and hold the film motionless 

 when required. The box is impervious 

 to light, and has a lens pointing down- 

 ward, through which the main photo- 

 graph is taken. It has also another lens 

 pointing directly upward, which pro- 

 duces photographs at desired inter\-als 

 of the exact position of the compass and 

 aneroid needles situated in the holding 

 case above. This last-named photograph 

 automatically registers on the film the 

 direction and altitude of the 

 aeroplane when the exposure 

 was made. 



The film rollers arc driven 

 by a propeller through the 

 gear box. The hand le\er 

 controls the intervals of ex- 

 posure by varying the speed 

 of the shaft as compared 

 with that of the propeller. 

 The shaft may be operated 

 by hand through the lexer 

 and a single photograph he 

 taken, the i)ro|)eller lieing for 

 the moment put out of gear. 



The ingenious baseball sewing-machine which 

 pulls the covers together and stitches them 



A^v 



A Machine That Stitches 

 Baseball Covers 



SEWING-MACHINE has been in- 

 •ented for stitching together the 

 co\ers of a baseball. It has a mechan- 

 ism for holding the ball in position while 

 it is being stitched and pulls the covers 

 together over the ball while the stitch is 

 being taken. 



The clamping jaws hold the ball while 

 a wheel abo\e is turned to bring its 

 needle gripping fingers into position to 

 outwardly grip and release the needle 

 which sews the covers. A cam device 

 regulates the needle action. 



This can will trap every 

 inquisitive animal that 

 sticks its head into it 



Trapping Animals by 

 "Canning" Them 



AFI\T£-gallon gasoline can 

 . cut at the top from 

 corner to corner and with 

 the sharp edges bent inward, 

 constitutes a trap foranimals 

 that never fails to work. 

 When the animal enters the 

 can with its heat! the sharp 

 edges pre\'ent it from ex- 

 tracting it and escaping. 



