89^2 



Popular Science Monihhj 



tank being so constructed as to give the 

 appearance of a lake or river." This last 

 master trick in illusion-making is, how- 

 ever, not explained but hides under the 

 easy phrase: "so constructed." He con- 

 tinues: "The track, however, soon emer- 

 ges from the tank and the rest of the 

 course passes through inclosures, all 

 above the water line, the interiors of 

 which are decorated and illuminated to 

 produce various effects. " Th? first in- 

 closure may be 

 entitled Sub- 

 marine View. 

 "Here will be 

 seen sharks, 

 divers, sunken 

 wrecks, marine 

 growths, etc." 

 The next inclos- 

 ure is advertised 

 as Under the Ice 

 at the North 

 Pole. "Here arc- 

 tic views may be 

 shown, such as 

 seals, walrus, Es- 

 kimos." Iron 

 balls suspended 

 within the in- 

 closure and in 

 the path of the 

 vessel (the car) 

 produce by con- 

 tact a grating or 

 grinding sound 

 "in imitation of 



icebergs striking the vessel." Such is the 

 inventor's idea of an iceberg! The port- 

 holes through which the passengers view 

 the wonders "are provided with convex 

 lenses which produce the desired illusion 

 of distance, swirling motion, etc." In 

 other words, they blur the vision to make 

 the passenger's imagination work more 

 willingly. "The illumination of the dif- 

 ferent inclosures is controlled by the 

 passage of the submarine," by electric 

 contacts on its dummy periscope. 



Altogether, there should be shocks 

 enough in a trip like this to provide the 

 least fertile imagination with thrills suf- 

 ficient to last the average individual quite 

 a while — and, incidentally, to make him 

 profoundly grateful that the trouble is 

 imaginary. Without that comforting 

 kno\\ledge enjoyment would be dubious. 



This shows how you can arrange beds for two 

 adults and one baby in your automobile 



Sleep in Your Automobile and Hang 

 Up the Baby for the Night 



A RESIDENT of Tropico, California, 

 has devised the novel automobile bed 

 equipment shown in the accompanying 

 illustrations. It accommodates two 

 grown-ups and a, child, adds not more 

 than twenty pounds to the outfit and 

 takes up no more room than an ordinary 

 "camper's" roll of bedding. 



Thebackofthe 

 front seat is cut 

 down so that it 

 can be dropped 

 backward, to fill 

 the space be- 

 tween the front 

 and the rear seats. 

 This makes a bed 

 of the interior of 

 the car, large 

 enough to ac- 

 commodate two 

 grown persons. 

 The bed for the 

 youngster con- 

 sists of a ham- 

 mock, which is 

 swung above the 

 bed. This ham- 

 mock may be 

 made of duck, 

 about thirty inch- 

 es wide by fifty- 

 two inches long. 



The Secret of the Wily Snake's 

 Sinuous Glide 



DID you ever watch a snake gliding 

 over the ground in graceful curves 

 and did you ever stop to think of the 

 mechanical principles involved in its 

 motion? The snake moves along the 

 ground in undulating curves produced by 

 the contraction of the longitudinal sys- 

 tem of muscles in alternate sections of its 

 body. That alone would not produce a 

 forward motion, however, were it not for 

 the friction of the scales on the underside 

 of the snake's body against the rough- 

 nesses of the ground. By bracing the 

 rear part of the body, the forward part 

 is enabled to glide forward and by re- 

 versing the process the rear part is 

 dragged forward to a new position. 



