TECHNICAL INDEX AND GLOSSARY 



matter. See Vol. IV, p. 180; also, "Pasteur and the Germ 

 Theory of Disease," Vol. IV, p. 217; also, "Life Problems," Vol. 

 V, p. 220. 



Static Machine. A machine for generating static, or frictional, 

 electricity. It consists of a large circle of glass so arranged that 

 its surface can be revolved rapidly against a suitable friction 

 producer. Until the beginning of the nineteenth century static 

 machines were the only kind of apparatus known for generating 

 electricity. See "Progress in Electricity from Gilbert and Von 

 Guericke to Franklin," Vol. II, p. 259. 



Statics. The science that deals with stationary bodies in 

 equilibrium or under conditions of stress or strain. 



Steam. Water in a gaseous state. Water becomes gaseous at 

 sea-level at a temperature of 2i2F., or iooC. 



Steamboat. See "Steam Engine" of the present index, and in 

 particular "The Highway of the Waters," Vol. VII, p. 56. 



Steam Engine. For the story of the development of the 

 steam engine, see "Ctesibus and Hero: Magicians of Alexandria," 

 Vol. I, p. 242; "Captive Molecules: The Story of the Steam 

 Engine," Vol. VI, p. 79; "The Master Worker," Vol. VI, p. no. 

 For the application of steam in various fields, see "The High- 

 way of the Waters," Vol. VII, p. 56; "The Steam Locomotive," 

 Vol. VII, p. 119; "From Cart to Automobile," Vol. VII, p. 152. 



Steam Locomotive. See "Locomotive" of the present index. 



Steel. Is an alloy of iron and carbon; or a modified form of 

 iron containing more carbon than wrought-iron and not as much 

 as cast-iron, as a rule, although some mild steels contain as little 

 carbon as wrought-iron. See "The Age of Steel," Vol. VI, 

 p. 271. 



Steelyard. An old-fashioned and primitive form of balance 

 for weighing objects. The principle upon which the steelyard 

 works is that of a lever of the first class. 



Stethoscope. An instrument for listening to the sounds of 

 the internal organs, particularly the lungs and heart. It con- 

 sists essentially of a hollow tube, funnel-haped, which collects 

 and concentrates the sound waves, just reversing the action of 

 the megaphone. It was invented by Laennec, a French physician, 

 in 1815. See Vol. IV, p. 201. 



Storage Battery. An electric battery for collecting and storing 

 electricity. For the recent improvement in storage batteries, 

 including the invention of Thomas A. Edison, see "Storage 

 Battery Systems," Vol. VII, p. 188. 



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