during rapid rotation, are always in the same direction as those de- 

 rived from the slowest rotation, and which continue to act after the 

 rotation has ceased, but are greater in intensity ; and that the for- 

 mer effects are such as might have been looked for from a know- 

 ledge of the latter. 



Some Account of the Transit Instrument made by Mr. Dollond, and 

 lately put up at the Cambridge Observatory. Communicated April 

 13, 1825. By Robert Woodhouse, A.M. F.R.S. Read May 19, 

 1825. [Phil. Trans. 1825, p. 418.] 



The author in this paper first describes the operations by which 

 the new transit instrument at the Observatory of Cambridge was 

 approximatively placed, so as to allow of a meridian mark being 

 erected on the distant steeple of Granchester church. He then en- 

 ters into a more full consideration of the different methods proposed 

 and employed by astronomers for executing the more delicate ad- 

 justments of the transit in general ; he shows how the errors of col- 

 limation, level, azimuth, and the clock, may all be detected, and their 

 values determined, by the resolution of certain equations of the first 

 degree, constructed from observations of any three or more stars ; 

 but this method, though exact in theory, he reprobates in practice, 

 and prefers making each adjustment separately and by the ordinary 

 mechanical trials, as shorter, more effectual, and less troublesome. 

 Mr. Woodhouse then describes a remarkable phenomenon presented 

 to him by the transit in the course of his observations. He found 

 that the line of collimation of the instrument deviated occasionally 

 to the east or west of the centre of the meridian mark, without any 

 apparent reason. At length, however, it was found that this was 

 caused by the approach of the assistant's body to the lateral braces, 

 placed for the purpose of steadying the instrument in an invariable 

 position at right angles to its axis. The expansion of the brace 

 nearest to him was found to thrust the axis of the telescope aside ; 

 and on the removal of the assistant, the equilibrium of temperature 

 restoring itself, the deviation gradually disappeared. That this was 

 the true cause, appeared by wrapping hot cloths round the alternate 

 braces, by which the same effect was produced in an increased de- 

 gree. Warned by these observations, Mr. Woodhouse ordered a 

 proper apparatus to be provided, to defend the braces from the sun's 

 rays, during the meridian passage of that luminary. 



On the fossil Elk of Ireland. By Thomas Weaver, Esq. Member of 

 the Royal Irish Academy, of the Royal Dublin Society, and of the 

 Wernerian and Geological Societies . Read May 19, 1825. [Phil. 

 Trans. 1825, p. 429.] 



Mr. Weaver's principal object in this paper is to prove that the 

 remains of the gigantic elk, which have been found in various parts 

 of Ireland, are not of antediluvian origin, but that the animal lived 



