85 



and S. of the line of pipes. The resulting dip, by one needle, at No. 

 4, was 71° 43'.2, differing 4'. 3 from that observed at No. 3. It 

 seems, therefore, by the comparison of stations Nos. 1, 3, and 4, that 

 the presence of this iron will not explain the differences at stations 

 Nos. 1 and 2. Major Graham found the dip, with the same instru- 

 ment, in the Magnetic Cabinet of the Botanic Garden, St. Mary's 

 College, on the 11th June, between 6£ and !\ A - M., 71° 38'.8 



Professor Bache then communicated the following tabular 

 view of the observations heretofore made at Baltimore, arranged 

 according to the stations and dates. 



Station. Observer. Date. Dip. 



1 Holliday Street, nearly opposite ° ' 



the Theatre, Prof. Courtenay. July 19, 1834 70 58.6 



2 In the grove, N. of the Wash- 



ington Monument, Prof. Loomis. Sept. 25, 1839 71 50.3 



3 N. 5° E. (Magnetic) 3G3 yards 



from centre of Washington 

 Monument, supposed the same 

 station as that of Prof. Loomis, 



4 In the Second Square, N. E. of 



Washington Monument, 

 r. 



" 55 55 55 



" 55 55 55 



7 At two points between 3, and 4, 



5,6, 



8 In the Botanic Garden, St. 



Mary's College, 

 9 



a 55 55 55 



The results obtained by different observers and with different in- 

 struments are, Professor Bache remarked, remarkably accordant, and 

 leave no doubt of the care with which the observations were made, or 

 of the value of the instruments. 



Mr. Lea mentioned to the Society, that Mr. Lyell is about 

 to visit this country, upon the invitation of the Lowell Insti- 

 tute, to give lectures before that body. He announced also 

 that M. Ramon de la Sagra is about to publish a Journal of 

 Natural History at Havana, and that he invited communica- 

 tions for the work. 



Mr. Kane submitted the following resolutions, which were 

 adopted: 



Resolved, That a committee be appointed to negotiate with 



Maj. Graham. 



June 10,1841 



71 47.2 



Prof. Bache. 



Aug. 27, 1840 



7134.4 



Mr. Nicollet. 



Apr. 28, 1841 



7134.9 



Maj. Graham. 



June 10, 1841 



71 31.9 



55 55 



55 55 



71 45.3 



Mr. Nicollet. 



Apr. 28, „ 



71 38.6 



Maj. Graham. 



June 11, „ 



71 38.8 



