xl REPORT. — 1851. 



tliough the title of President may not be connected with the highest talent 

 or the most universal knowledge in this great assembly, you shall neverthe- 

 less find that it is not attached to the least industrious or the least ardent of 

 its members. 



It is required by the custom of the Association that at the opening of each 

 of its meetings the President should lay before the Association such remarks 

 on the state of those sciences which are included in its objects, and especially 

 such an account of their progress in the past year, as he may judge suitable 

 to the time and serviceable for the guidance of the Association in the conduct 

 of the commencing meeting. I find it impossible to give even the most sum- 

 mary statement of this nature without alluding to the acts of the Association, 

 and to the establishment or modification of other institutions connected with 

 Science or Art ; and 1 propose, therefore, to submit to you the mingled hi- 

 story of the progress of Science, — of the efforts, the successes, and the failures 

 of the Association in reference to it,-^and of the state of some other insti- 

 tutions. In some departments I fear that my account will be extremely de- 

 fective : ,1 trust, however, that those of my hearers who may be sufficiently 

 interested in this Address to notice its omissions will not fail to use the op- 

 portunities of various kinds which the discussions in the Sectional meetings 

 afford for supplying them. 



Commencing, then, with the subject which stands first in the Reports of 

 the Association, and on which the funds of the Association have been most 

 generously expended and its influence very energetically employed, I remark 

 that the progress of Astronomy in the last year has been very great. The 

 Earl of Rosse has been much engaged in experiments on the best methods 

 of supporting and using his large mirrors. The construction adopted some 

 time since is still retained ; namely, a system of levers distributing their 

 pressures uniformly over eighty-one points, each pressure being transmitted 

 through a small ball which permits to the mirror perfect freedom of slipping 

 in its own plane, so as to take proper bearing in the chain or hoop which 

 supports it edgeways. To Lord Rosse's critical eye the effect even of this 

 imounting, though greatly superior to that of any preceding, is not quite 

 perfect. In the progress of the experiments, some singular results have been 

 obtained as to the set which a metal so hard as Lord Rosse's composition 

 may receive from an unequal pressure of very short duration. A surface of 

 silver, I believe, has now been successfully used for the small reflector. Of 

 the character of the discoveries in nebulae made with this instrument I can- 

 not briefly give any very correct idea. The most remarkable is, the disco- 

 very of new instances of spirally-arranged nebulae : but there are also some 

 striking examples of dark holes in bright matter, dark clefts in bright rays, 



