S3 SECTION PHYSICS. 



end to all competition, and science will henceforth have acquired, in a 

 firmer manner, both with regard to the past and to the present time, 

 that cosmopolitan character which it is so important for it to 

 assume. 



The CHAIRMAN : Ladies and Gentlemen, you have anticipated, as 

 I am sure you would do, the proposal I intended to make of inviting 

 you to thank M. Tresca for his very lucid review of the instruments 

 contributed by France, and connected with some of the grandest 

 discoveries of the French savans, but for the few words he has 

 been so good as to utter, they might pass unnoticed by a great number 

 of persons. The names of Biot, Arago, Becquerel, Ampere, Daguerre, 

 Fizeau, Pascal, Savart, Fresnel, Lavoisier, Dulong and Regnault are 

 all historical names in science, and we are very happy to have even a 

 small portion of the apparatus which they used. I need only refer to 

 this wonderfully simple piece of apparatus devised by Ampere for 

 the foundation of the electro-magnetic discoveries with which 

 science has been enriched by so many savans, not the least amongst 

 them our own Faraday. The ingenious instruments, which M. 

 Tresca has passed so rapidly in review, recall one's recollection to 

 one's reading and experience respecting the progress of science during 

 the last fifty years, and if the next fifty years are only as prolific in 

 discoveries as the last it will indeed be a privilege to live in the days 

 in which they occur. The last outcome of the work is the production 

 of magnets of great power by M. Jamin ; I possess one which is so 

 powerful that it will allow itself to be held out horizontally by its 

 armature. Many years ago the Dutch were considered to construct 

 the strongest magnets, but by this beautiful arrangement of magnetic 

 plates attached to each other far more power is obtained. M. Tresca 

 has also alluded to a photograph produced by the red rays by 

 Becquerel. We all know that the red rays and the ultra red rays 

 possess very little actinic power. Their study has been taken up 

 recently by Captain Abney, and we may hope some day to get the 

 whole spectrum, not only photographed but also fixed ; it was photo- 

 graphed some time back by M. Becquerel, and this case, which is 

 very properly locked, so that it cannot be opened except under proper 

 precautions, for exposure to strong daylight would spoil it, contains 

 his photograph of the whole spectrum in its natural colors : And the 



