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POPULAR SCIENCE MONTHLY. 



the stimulus which it afforded to similar enterprises in other 

 States/' 



A few years later, in 1829, we find Dr. Caldwell purchasing of 

 W. and S. Jones, mathematical instrument makers, London, the 

 equipment for an electrical laboratory at the University of North 

 Carolina. The first item on the bill, which lies before me as I 

 write, is " a three-feet plate electrical machine with large branch 

 conductor, supported by two glass pillars, double collectors, 

 mounted in strong mahogany, varnished frame, with six brass 

 legs fitted into brass sockets and screw nuts, negative brass con- 

 ductor on claw- feet stand from the ground, with connecting slid- 



Pkof. Mitchell's Laboratory and Observatory. 

 After photograph by Collier Cobb. 



ing tubes, brass bells and wires, etc., 45." The total amount of 

 this first bill for electrical apparatus was 153 4s. 6d 



Dr. Caldwell published a Compendious System of Elementary 

 Geometry, in seven books, to which an eighth is added, containing 

 such other propositions as are elementary ; subjoined is a Trea- 

 tise on Plane Trigonometry. He was one of the earliest advocates 

 in the South of popular education by the State. 



Dr. Mitchell was the author of a Manual of Chemistry, a second 

 edition of which was passing through the press at the time of his 

 death ; a Manual of Geology, illustrated by a geological map of 

 North Carolina ; a Manual of Natural History, and a Geography 



