Mathematical and Physical Science. 305 



The author referred, in conclusion, to the forms of wave- 

 crests, and heights, modified by crossings, interferences, and 

 reflections. 



Mr Scott Russell said he felt a familiar interest in the re- 

 sults of Dr Scoresby's observations. The Section was aware 

 that great doubts existed as to the actual heights of the waves 

 of the open ocean. It was now past all doubt that waves 

 24 feet high, 30 feet high, 43 feet high, and with the swelling 

 crest even exceeding 45 feet high, actually existed and were 

 observed. From the observations which he had conducted 

 many years since, he had ventured to draw up a table pre- 

 dicting the velocities of sea waves up to even 1000 feet from 

 trough to crest in length. Although the apparatus which 

 he had used did not enable him to experiment on waves 

 which exceeded 16 inches in length, — yet from these pigmy 

 waves it was most interesting to see how accurately the law 

 was obtained ; for in his table the velocity of a wave whose 

 length was 600 feet was set down at 30 or 31 miles per hour, 

 Dr Scoresby's actually observed velocity for this wave was 

 32 miles and a fraction. 



Lord Northampton begged to remark, that this was one 

 of the many instances of the value of the British Association 

 as a handmaid to science. It brought together two such 

 gentlemen as Mr Russell and Dr Scoresby, and showed the 

 accuracy of the laws deduced by one from experiments con- 

 ducted on a microscopic scale, by the test of others observed 

 amid the sublime scene of the great Atlantic. 



Professor G. G. Stokes read a memoir " On Metallic Re- 

 flexion,'' and another " On a Fictitious Displacement of 

 Fringes of Interference." — Rev. Professor Powell " On the 

 Refractive Indices of several Substances." 



VOL. XLIX. NO. XCVIII. — OCTOBER i860. 



