500 NATURE-STUDY 



scope, telescope, observatories, camera,* the eye.* Use 

 simple diagrams. Do not try to apply law of refraction or 

 find the image with the diagrams except in the simplest 

 manner. 



Magnets,* battery,* electro magnet,* electric bell,* tele- 

 graph,* telephone, electric light,* electric' motor,* electric 

 street car.* Examine these and note construction and man- 

 ner of operation. Simple explanations are hard to give. 

 Do not go into theory. Use simple analogies, or try not to 

 explain at all, and simply be satisfied to show the general 

 construction and the actual operation. Emphasize rather 

 the practical utility of these inventions. 



Visit a modern newspaper printing press. Study the 

 history of printing. 



References: Physics: 251, 250, 255, 259, 317, 318, 257, 

 258, 260, 261, 249. Invention: 292, 286, 287, 296, 288, 289, 

 285, 321, 316. Boys' Books of construction and experiment- 

 ing: 276, 279, 280, 281, 282, 284, 298. Biography: 405, 

 406, 407, 321. 



Chemistry:* Experimental study of elements, com- 

 pounds, analysis, air, water, constituents of each, oxygen, 

 hydrogen, nitrogen, carbon, fire, carbon dioxide, sulphur, 

 gunpowder, matches, illuminating gas, kerosene. Properties 

 of soda, salt, ammonia, muriatic acid, soap, lye. 



Photography: Teach the process in a general way. If a 

 dark room is available teach developing and printing. Dis- 

 cuss in a simple way the modern photomechanical processes 

 — half-tone and three-color photography. 



References: Chemistry: 270, 273, 263, 264, 269, 262, 

 268, 274, 317, 318. Inventions: See physics above. 



Physiology and Hygiene: Systematic review of the 



