BIOGRAPHICAL INDEX 



mals at a distance of two hundred ells, the cur- 

 rent being conveyed by small wires. 



Gray, Asa, iv, 175. Born at Paris, New York, 

 Nov. 18, 1810; died at Cambridge, Mass., Jan. 30, 

 1888. American botanist. Professor of Natural 

 History at Harvard, 1842-88. Championed Dar- 

 win's theory of evolution, and wrote "Darwin- 

 iana" in 1876. Some of his best-known works 

 are, "Elements of Botany," "Flora of North 

 America," "How Plants Grow," "Field, Forest 

 and Garden Botany," and "Manual of Botany of 

 the United States." 



Gray, Prof. Elisha, vii, 85; viii, 26. Born at 

 Barnesville, Ohio, Aug. 3, 1835 ; died at Newton- 

 ville, Mass., Jan. 20, 1901. American inventor. 

 Remembered particularly for his inventions rela- 

 ting to telegraphy and the telephone. He filed 

 specifications of a telephone in the United States 

 Patent Office only a few hours later than Dr. 

 Graham Bell, whose invention opened the era of 

 telephonic communication. 



Gray, Stephen, ii, 262. Died February 25, 

 1736. A pensioner of the Charter House in Lon- 

 don. In his experiments with electricity he dis- 

 covered two of the most important properties of 

 electricity that it can be conducted and insu- 

 lated. 



Guericke, Otto von, ii, 213. Born at Magde- 

 burg, Prussia, Nov. 20, 1602; died at Hamburg, 

 May n, 1686. German natural philosopher. He 

 invented the first electrical machine, and dis- 

 covered electrical attraction and repulsion. He 

 invented the air pump and the air balance, and 

 demonstrated the pressure of the atmosphere 



