312 



Dr. B. H. Coates announced the decease of Charles Nagy of 

 Pesth, in Hungary, a memher of this Society, who died in the 

 year 1849. 



Prof. Haldeman announced the death of Don Manuel de 

 Naxera, of Mexico, a member of the Society. 



Colonel Graham, in alluding to the well known accuracy afforded 

 by the electric teleyjraph in determining differences of longitude, said 

 he had understood that the British authorities were now testing the 

 accuracy of a number of points, determined in longitude by the of- 

 ficers of engineers attached by the American and British govern- 

 ments to their respective commissions, for ascertaining and marking 

 the boundary under the Treaty of Washington of 1842. These 

 points are on and near the river St. John, and at other stations where 

 the telegraphic wires have been extended. 



The tests, he understood, were being made by electric connections 

 with the meridian of Harvard College Observatory at Cambridge, 

 Massachusetts. Whenever the results, which may be thus obtained, 

 shall be announced, it may be a matter of some interest to compare 

 them with those obtained before the invention of the electro-magnetic 

 telegraph. Previous to this invention we were obliged to depend on 

 direct observations upon the heavenly bodies, for determining initial 

 or primary longitudes at suitable intervals a])art, and then generally 

 to obtain intermediate points by the transmission of chronometers to 

 and fro between these primary meridians. Now the chronometers 

 remain at rest at the observing stations, and are compared by electric 

 signals transmitted along the telegraphic wires, thus avoiding all errors 

 in the run of the chronometers, produced by the jolting of vehicles, 

 and other accidents incident to travelling with them. 



Col. Graham concluded by saying that the table at pp. 366 to 369, 

 of the American Almanac lor the year 1848, gives the positions of a 

 number of points in New Brunswick, Canada, Maine, Vermont, New 

 York, &c., as determined by himself and his assistants on the part of 

 the American commission of boundary, which are now being sub- 

 jected to the tests above alluded to. 



The following is a copy of the letter from Col. Graham, read 

 this evening. 



