] 
‘ 
a of the British Association. : 3983 
accuracy, and of the observers, (all natives: of India,) Mr. C. re- 
marks that after the first difficulty of instructing them is sur- 
- mounted, their patient, diligent and temperate habits peculiarly 
fit them for the office here required of them, and I have always 
found those who have been selected for the duty full as trustwor- 
thy as any class of persons probably, to whom such observations 
are usually intrusted. For the two years ending June 30, 1838, 
the mean temperature of the station was 78°.79: the mean dew 
point 71°.78. The barometric registers give, by a mean of all 
the diurnal semi-oscillations, the following results: 
Fall between 10 A. M. and 4P.M. . .-.109 inch. 
Rise  “ AP, M.and10A.M. . . .108 “ 
Balk uf 10 4: Mand: 4-AcM, feeing ADTL =f 
Rise “ AA. M.and10A.M...:. .073 * 
Times of maxima, between the hours of 9 and 10 morning 
andevening. ‘limes of minima, between those of 3 and 4 after- 
hoon and morning. 
¥ Mr. Scott Russell read the report of the Committee on Waves. 
All the objects confided to this committee, (consisting of Sir John 
Robinson and himself,) having been fully accomplished, the re- 
port vow presented was to be considered as final. That part of 
the duties of the committee which related to the connexion of 
the phenomena of waves with the resistance of fluids to solids, 
had devolved upon them under a separate name, as the committee 
on forms of vessels, and would be reported under a separate head. 
The wave form of vessel, however, had been now proved to pos- 
Sess so many advantages, that its use seemed likely to become 
general, and thusa great change would be effected in naval ar- 
chitecture. Prof. Kelland read a communication on the theory 
of waves,—Sir D. Brewster communicated a paper on Prof. Pow- 
ell’s mealies of the indices of refraction for the lines G and H 
in the spectrum ; and Prof. Powell one on an experiment of in- 
terference of light. . 
On a blue sun seen at Bermuda. Sir D. Brewster communi- 
cated a letter from Lieut. Col. Reid, governor of the Bermudas, 
wenn a letter from Dr. A. W. Harvey, of Bermuda, who states 
that on the 11th and 12th August, 1831, immediately after a hur- 
tieane which devastated Barbadoes, the sun appeared of a bluish 
Color, and its light was unusually dim. This was owing, as Sir 
D. Brewster imagined, to the interposition between the sun and 
