488 ANNALS NEW YORK ACADEMY OF SCIENCES 



SECTION OF ASTRONOMY, PHYSICS AND CHEMISTRY. 



Mat 18, 1908. 



Section met at 8:15 P. M., Vice-President Hering presiding. 



The minutes of the last meeting of the Section were read and approved. 



The following program was then offered: 



J. P. Simmons, Note on a Curious Effect Produced by the 



Explosion of Detonating Gas. 

 William Campbell and R. F. Bbhler, The Heat Treatment of Carbon 



Tool Steels. 

 Charles Lane Poor, An Investigation of the Figure of the Sun 



AND OF Possible Variations in its Size and 



Shape. 

 Charles Lane Poor, The Photoheliometer. 



Summary of Papers. 



Mr. Simons said in abstract: When a mixture of oxygen and hydrogen 

 is exploded in a tube, the inside of which is coated with a thin layer of water, 

 perfect rings are formed. The same phenomenon has been noticed when 

 the same kind of a gas mixture is exploded in a tube, the inside of which is 

 coated with a thin layer of wax. This is a heating effect, since the rings 

 formed in the tube covered with wax are made apparent by the melting of 

 the latter substance. This periodic heating is probably due to compressions 

 arising from either sound or explosion waves. 



Professor Campbell and Mr. Bbhler, in their paper, first classified the 

 various constituents of unhardened and hardened high carbon steels; namely, 

 cementite, pearlite, ferrite, graphite, austenite, martensite, troostite, os- 

 mondite and sorbite, and gave in tabular form the views of the different 

 authorities on their constitution. The plan of study embraced (1) heating 

 to various temperatures and (a) slow cooling, (b) quenching, (c) tempering; 

 (2) the effects of forging temperature and quenching temperature, to see 

 whether the structure gave any evidence whether overheating had taken 

 place during forging at the works of the manufacturer or during reheating 

 for hardening at the user's, in the case of faulty material; also whether this 

 persisted after tempering. Only the maximum forging temperature left 

 any traces after quenching and this was much above that used in practise. 



