TRANSACTIONS 



AMERICAN PHILOSOPHICAL SOCIETY. 



ARTICLE I. 



Astronomical Obsrrralio>is made at Hudson Observatory, I Attitude 11 II 12 .6, north, and 

 Longitude ih. 25/n. 39s.5, west. Third Scries. By JUias Loomis, I'mfi ttor of Matin vutict 

 and Natural Philosophy in the I'nivcrsity of the City of New York. Kind NoVBnbtt l->. 

 1844. 



The general plan of observation has remained unchanged since the foundation of the 

 observatory. The clock has not been stopped Bines January 31, I s I": bul from the 

 effects of dust and moisture, operating upon the pendulum and wheels, its rale has tx • n 



somewhat affected, as will be seen from pages four to seven. The third spider I t 



the transit broke, April 20, 1841, and its place was supplied bj the moveable micronx ti r 

 line for a few days, until it could be replaced. July 14th, the fourth line broke, and the 

 micrometer was substituted in its place. November 1 « > 1 1 i the micrometer broki i and 

 December 28th, the second line also broke, leaving only three vertical lines. ipril 21, 

 I v 12, 1 undertook to replace all the linos, and, after Bome ineffectual attempts, sui 1 1 1 ded 

 in introducing fibres of silk from the cocoon. The linos, seven in Dumber, m re secured 

 in their places by bees-wax, melted bj a warm inm. These lines are a little coarser than 

 the spider lines, are not quite so smooth, and arc not perfect]) Btraight Neverthek 

 by always observing transits on tin same pan of the lines, this last evil is mosthj obviated. 

 The equatorial intervals deduced from the transits of one hundred Stan obsi rved at all the 

 wires, have been determined bjb follows: — 



18.033; 18.5:17; 18.695; 19.123; 17.047; 18.679 



VOL. X. 1 



