23 



Professor Henry examined in the same connexion, whether 

 currents of ordinary electricity pass actually at the surface, or, 

 like galvanic electricity, through the mass of the conductor; 

 and he concluded that the law of conduction developed by 

 Ohne cannot apply to the case of surface passages, as these are 

 indicative of ordinary electricity. 



Mr. Walker submitted a communication on behalf of Dr. 

 Locke, of Cincinnati, in which he stated that he had calculated 

 his magnetic observations, and that he was led to infer that the 

 Doint of greatest magnetic intensity in North America is to the 

 N. W. of Lake Superior, near its extremity, and not near Hud- 

 son's Bay, as supposed by Col. Sabine. 



Prof. Bache remarked, that Lieut. Lefroy is now engaged in 

 the magnetic survey of British North America, and that his 

 results, in conjunction with those of Dr. Locke and others, 

 would definitively settle this contested point. Prof B. also 

 read an extract from a letter of Col. Sabine, mentioning that 

 he had received the term-day observations of Lieut. Lefroy at 

 Lake Winnipeg, and that an excellent northern station for the 

 term-days would be had at Lieut. Lefroy's winter quarters. 



Prof. Bache added, that the extra term-days of July had 

 been kept, and the daily observations made on the first ten 

 days, at the Magnetic Observatory of the Girard College. 



A communication of Prof. Henry, in continuation of his 

 researches on electro-dynamic induction, was referred to a 

 Committee, consisting of Dr. Patterson, Prof. Bache, and Mr. 

 Lukens. 



Dr. Ludlow, from the Committee on the report of the So- 

 ciety's scientific proceedings during the past century, pre- 

 sented a request that the Committee should be discharged from 

 further action under the resolution of the Society: and there- 

 upon, on his motion, the Committee was discharged. 



