113 



is now cultivated in America, and to the valuable matter re- 

 cently contributed by American astronomers. 



Dr. Patterson remarked, that this discovery of Bessel fur- 

 ther increased the difficulties of Practical Astronomy. First, 

 the stars were considered as fixed; afterwards, their proper 

 motions were ascertained, but were supposed to be uniform. 

 Now these proper motions are found to be variable. 



Mr. Walker observed, that there was difficulty in supposing 

 the existence of an opake centre of attraction, and that possibly 

 the stars Sirius and Procyon were stellar systems not divisible 

 by our telescopes. 



Mr. Walker gave a brief account of the progress of Profes- 

 sor Kendall's observations at the High School Observatory, 

 since the mounting of the Ertel Meridian Circle. 



The circle had been tested by reading with each of the four ver- 

 niers, for every 5°, and the circle was found not to have been injured 

 in transition, nor in mounting. The average reduction of the read- 

 ing of any one vernier to that of the mean of the four being about 3". 

 Although 50 feet high, the insulated tower was so still that the stars 

 could be observed with great facility and certainty, by reflection from 

 quicksilver, with a power of 200. The first trials of the instrument 

 had given for the latitude of the Observatory 39° 57' 7"; and the 

 polar point determined by any two successive culminations of polaris 

 differed not more than 1" from the point obtained by the fundamental 

 stars, using for their declinations the most recent values given by 

 Bessel and Airy. 



Mr. Walker also remarked, that the latitude found for the High 

 School Observatory, by Mr. Paine, with the sextant of the Massachu- 

 setts Survey, as well as that which Messrs. Kendall, Riggs and him- 

 self had found from sextant observations, — after applying to the de- 

 clinations of the stars formerly used, the more recent corrections of 

 Airy, — differed less than a second from the indications of the Ertel 

 Meridian Circle. 



Mr. Walker regarded this coincidence as confirmatory of his former 

 remai-ks on Mr. Paine's method of determining latitudes by a sextant, 

 in the Proceedings, Vol. II., page 1 66 ; a conclusion of great impor- 

 tance, when we consider that all the latitudes of the Massachusetts 

 survey depended upon this method. 



He further stated, that Professor Kendall and his assistants had 



