1 866.] President's Address. 283 



* 



not so much on his work in this department of zoology as on his lahours 

 in a very different and much more difficult branch of anatomy. Vertebrate 

 Osteology. 



In 1860 Mr. Parker published a memoir ''On the Osteology of Balceni- 

 ceps Rexy^ and in 1862 another "On the Osteology of the Gallinaceous 

 Birds and Tinamous/' in the Transactions of the Zoological Society ; 

 while a third still more important memoir, on the " Skull of the Ostrich 

 Tribe,'* was read before the the Royal Society in March 1865, and is now 

 published in the Philosophical Transactions. In these elaborate and 

 beautifully illustrated memoirs, Mr. Parker has not only displayed an ex- 

 traordinary acquaintance with the details of Osteology, but has shown 

 powers of anatomical investigation of a high order, and has made important 

 contributions towards the establishment of the true theory of the vertebrate 

 skull. 



Mr. William Kitchen Parker, 

 I present you with this Medal in testimony of the high esteem in which 

 your investigations are held by those of our body who are qualified to 

 appreciate them, and who look at once with approval and with expectation 

 at the increased and still increasing interest of the communications contri- 

 buted by you to our Transactions. 



The Council have awarded the Rumford Medal to M. Armand Hippo- 

 lyte Louis Fizeau for his Optical Researches, and especially for his Inves- 

 tigations into the Effect of Heat on the Refractive Power of Transparent 

 Bodies. 



In 1849 M. Fizeau rose into celebrity as the experimenter who first 

 succeeded in measuring the velocity of light by observations limited to 

 objects on the surface of the earth. He noted the time required for the 

 passage of hght from the place of the observer to a mirror, normal to the 

 path of the light, 8633 metres distant, and back again, by means of a 

 wheel having 720 teeth revolving rapidly. When the wheel made 126 

 revolutions in 10 seconds, the light that had passed through the notch 

 between two teeth towards the mirror was stopped completely on its re- 

 turn, after reflexion, by the second of the two teeth ; showing that the light 

 had travelled 17,266 metres while the wheel had revolved through half the 

 angle subtended at its centre by the distance between the summits of two 

 adjacent teeth, or second. 



In 1859 he wrote a remarkable memoir, '' Sur une experience qui parait 

 demontrer que le mouvement des corps change la vitesse avec laquellc 

 la lumiere se propage dans leur interieur." 



His " Methode propre a rechercher si Tazimuth de polarisation du 

 rayon refracte est influence par le mouvement du corps rcfringent" (1860) 

 involves such complicated arrangements that great hesitation was felt 

 about accepting the results. But whoever has seen his experiments on the 



