48 Proceedings of the American Philosophical Society. 



In the experiments of De la Rive and Marcet, in which the entering 

 air being made to impinge upon the bulb of a thermometer, was pro- 

 ductive of a fall in the thermometric column, it might be inferred, he 

 conceived, that the bulb interfered with the access of caloric from the 

 space. It was in fact the bulk upon which the air acted previously to its 

 distribution in the space where it could have encountered the due propor- 

 tion of caloric. 



Prof Bache, from the committee on magnetic observations, read an 

 extract from a letter of Major Sabine, V. P. of the Royal Society of Lon- 

 don, stating that the Council of the Society had, on the recommendation 

 of the Committee of Physics, expressed their opinion of the importance 

 to the plan of combined magnetic observations now in progress, that ob- 

 servatories should be established in the United States, and had instructed 

 their President to bring this expression of opinion to the knowledge of 

 the government of this country. 



Prof Bache stated that the resolution just referred to had been adopted 

 with a view to aid the efforts of this Society in procuring the erection of 

 observatories, as recommended in their memorial to the Secretary of War, 

 which had been referred by that officer to Congress. 



He also read an extract from a subsequent letter from Major Sabine, in 

 reference to the progress of the combined magnetic observations, stating 

 that the Emperor of Russia had ordered the erection of nine magnetic 

 and meteorological observatories in his dominions, to conform, in respect 

 to instruments and times of observations, to the system recommended by 

 the Royal Society. One of these observatories is to be upon the north- 

 west coast of America. 



Prof Bache stated, that the regular system of bi-hourly magnetic and 

 meteorological observations was now established in the observatory at the 

 Girard College, and had been in progress since the close of the month of 

 May. He intended, at a future day, to present to the Society the names 

 of the gentlemen, chiefly members of the American Philosophical Soci- 

 ety, by whose contributions a fund had been raised to defray the expense 

 of employing the assistants required for these observations. 



On the occasion of the May magnetic term-day for observations at short 

 intervals, [29th,] a brilliant aurora had occurred, during which the mag- 

 netic instruments were very much disturbed. The details were reserved 

 for future presentation, but it was perhaps proper now to state, that an 

 auroral arch had been visible here a little after ten o'clock. The same 

 phenomenon was observed at Southwick, Mass., by Mr. Holcomb, at a 

 much earlier hour. 



July 17. — Dr. Hare made a communication respecting an extensive 

 voltaic apparatus, of the form which he had designated by the name of 

 galvanic deflagrator. This apparatus had been constructed for the Lowell 

 Institute of Boston, under his direction, by request of Prof Silliman. 



