26 PROCEEDINGS OF SECTION A. 



2. On " The Measurement of High Resistances and on 

 Galvanometers suitable for the purpose." 



3. On " The Clark Cell as a means of obtaining a Standard of 

 Current, and on its application in the Construction of a Graded 

 Galvanometer for the use of tlie Prince Alfred Hospital." This 

 last in conjunction with Mr. Pollock. 



Meeting of Section A, held on Wednesday, August 29th. 

 The President, Mr. R. L. J. Ellery, F.E.S., in the Chair, 



The President delivered the following Addi'ess : — 



ON THE PRESENT POSITION OF ASTRONOMICAL 



KNOWLEDGE ; 



Ladies and Gentlemen, — The Australasian Association for tlie 

 Advancement of Science, just organised, having done me the honour 

 of electing me President of Section A, embracing Astronomy, 

 Mathematics, Physics, and Mechanics, I propose to open tlie 

 proceedings with a biief address on " The Present Position of 

 Astronomical Knowledge," but in doing so I must content myself 

 with a very superficial review of tlie most prominent and 

 interesting features in recent progress of knowledge concerning 

 the tenants of space, the most generally received views upon 

 various theories and hypotheses relating to their constitution, and 

 an indication of the stage at which we have arrived in tlie 

 perfection of our instruments and methods of research, and the 

 difficulties besetting further advance. 



If we look back to the time this great city was founded, about 

 a hundred years ago, we find that our greatest advance since then 

 has been in the direction of Physical Astronomy. In Mathematical 

 Astronomy the world's knowledge was so much enriched during 

 the century following Newton's great work, that now, near the 

 end of the 19th century, our position is not remarkably beyond 

 what it was when Herschell first pointed his just finished forty- 

 feet telescope to the planet Saturn and discovered two new 

 satellites, now about one hundred years ago. In physical 

 astronomy, however, the additions to our knowledge during the 

 period referred to, and more particularly during the last quarter 

 of a century, may be regarded as little short of marvellous. 



Progress in Astronomy now depends in no small degree on 

 progress in its sister sciences, in optics, in electricity, especially 

 in photography, chemistry, and physics generally ; and as a new 

 departure is made in any of these branches of knowledge, some 

 new implement or some new power is furnished with which to 



