374 Proceedings of Scientific Societies. 



No. Locality. Carbon. Volatile matter. Ash. 



13. Tioga, - - ■ - - - .725 .175 .100 



14. Cumberland, Md., - - - .754 .170 .076 



15. Black Spring Gap. Grey vein, .860 .045 .095 

 A comparison between the coals of Cumberland, Md., Bloss- 



biirg, Penn., Dauphin Co., Penn. and South Wales, shows a re- 

 markable similarity of composition as respects volatile matter. 

 The greatest difference, in fact, scarcely exceeds one half of one 

 per cent, as will be seen by the following table. 



Art. XIII. — Proceedings of Scientific Societies. 



I. Anierica7i Philosophical Society. 



Nov. 6, 1840. — Professor Bache submitted to the Society a Chart, rep- 

 resenting the extraordinary variations of the magnetic declination during 

 the term day, on the 29ih of May last, prepared by W. C. Bond, Esq., from 

 the observations at the Magnetic Observatory at Cambridge. 



Professor Bache read an extract of a letter from Lieut. Riddell, direc- 

 tor of the Magnetic Observatory at Toronto, U. C, which stated that an 

 entire discordance had been found between the curve representing the 

 changes of inclination, on the February magnetic term day, at Toronto, 

 Dublin, Brussels, and Prague, whilst those at the last three named stations 

 agreed very well together. This result. Professor B. stated, confirms the 

 conclusions previously drawn from the observations at short intervals, of 

 Prof Lloyd and himself, in November last. 



Mr. Walker made some observations in relation to the Observatory of 

 the Harvard University, Cambridge, and stated that extensive arrange- 

 ments had been made, and were in contemplation, for prosecuting mag- 

 netic observations and practical astronomy. 



Professor Bache made a verbal communication of some recent deter- 

 minations of the magnetic dip, made by him at Philadelphia and Bal- 

 timore. 



He reminded the society, that on a former occasion he had submitted 

 a comparison of the observations for magnetic dip at various stations, com- 

 mon to the series of Prof Loomis, (Am. Philos. Soc. Trans Vol. VII, 



