ABSTRACTS 



Authors of scientific papers are requested to see that abstracts, preferably 

 prepared and signed by themselves, are forwarded promptly to the editors. 

 The abstracts should conform in length and general style to those appearing in 

 this issue. 



GEODESY. — General instructions for precise and secondary traverse. 

 U. S. Coast and Geodetic Survey, Special Publ. 58 (serial iii). 

 Pp. 48, figs. 5. 1919. 



The instructions are designed for the highest class of traverse, equal 

 in accuracy to primary triangulation, and for secondary traverse com- 

 parable in accuracy with secondary triangulation. R. L. F. 



APPARATUS. — A furnace temperature regulator. Walter P. White 

 and Leason H. Adams. Phys. Rev. 14: 44-48. July, 1919. 



By making the heating coil of an electric furnace one arm of a wheat- 

 stone bridge, and combining this with a galvanometer regulator, thus 

 keeping constant the resistance of the coil, we can, regardless of varia- 

 tions in the current-supply, and with no attention, maintain constant 

 the temperature of furnaces not too directly influenced by the tempera- 

 ture of the room, or where the surrounding air is kept constant. The 

 power available in this regulator is relatively very great; nothing has 

 to be inserted within the furnace cavity, and the lag is practically 

 nothing; the regulator is often nearly at its best under conditions most 

 unfavorable to other regulators. It has held a small furnace for hours 

 constant to 0.1° at temperatures from 500° to i4oo°C. 



W. P. W. 



PHYSICS. — Temperature distribution in solids during heating or cooling. 

 E. D. Williamson and L. H. Adams. Phys. Rev. 14: 99-114. 

 August, 1919. (Geophysical Lab. Papers on Optical Glass, No. 11.) 



In deciding on the best methods of carrying out various operations 

 in the manufacture of optical glass, it was found necessary to have some 

 idea of the temperature gradients in the pieces during heat treatment. 



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