British Association. 31 1 



practicable, but which the author thinks may be used with consider- 

 able effect. 



The second paper relates to a system of logarithms, which may be 

 used with great advantage in calculations. 



The Section the adjourned. 



Friday, Awjust 2{}th. — 1. Mr. Whewell gave an account of his 

 anemometer, which he described last year at Dublin, in an unfinished 

 state. — See Records, vol. ii. 218. 



2. Mr. Stevelly, on Mathematical Rules for constructing com- 

 pensating Pendulums. The author having found the rule given 

 by Kater erroneous, he endeavoured to lay down the true formulae. 



3. Mr. Phillips stated the results of his experiments, " On the 

 direction of the Isoclinal Magnetic lines in Yorkshire," to be, that the 

 lines of equal dip were not straight, but had considerable flexures 

 distinctly related to the elevation of the ground, the bcndings taking 

 place rapidly to the south, on two elevated ridges by which Yorkshire 

 is intersected. 



4. Sir JDaoid Brewster, *'0n a very simple contrivance for tracing 

 lines in the Solar Spectrum, which were invisible by other means." 

 This contrivance consisted merely in introducing a cylindrical re- 

 fractor between the eye and the eye-glass of the telescope. The 

 effect of this refractor was to give a linear form to the most irregular 



image 



5. Dr. Hare, on " Electrical Attractions and Repulsions, and 

 upon the Electric Spark. The object of this paper was to support 

 Franklin's theory, and to refer repulsion to the action of surrounding 

 bodies. 



6. Dr. Carpenter, on the method of teaching the blind to read. 



7. Mr. Russell, on " Some of the Elements of the resistances of 

 fluids." The laws of the resistances reduce themselves to, 1st, The 

 law of the emersion of the floating body from the fluid, which is 

 related to the velocity alone ; 2nd, The relation of the resistance of 

 the wave ; 3rd, The relation of resistance to a certain form of the 

 body. 



8. il/r. Hodghinson gave an account of his experiments on the 

 comparative strength of iron made with the hot and with the cold 

 blast. In most cases the hot blast iron seems to be somewhat but 

 not greatly weaker. Its specific gravity is also rather less, except 

 at the Devon works. The fracture of the cold blast was white, that 

 of the hot blast gray. No. 1 and 2 had less tenacity when prepared 

 by the hot blast. The opposite, however, was the case with the 

 Devon iron. No. 3, which by the hot blast was less hard but greatly 

 stronger. 



Section G. — mechanical science. 



President, Davies Gilbert, Esq. — F?ce Presidents, M. I. Brunei, 

 Esq., John Robison, Esq. — Secretaries, T. G. Bunt, Esq., G. T. 

 Clark, Esq., William West, Esq. — Committee, Captain Chapman, 

 G. Cubitt, Esq., J. S. Enys, Esq., William Hawkes, Esq., E. 

 Hodgkinson, Esq., Dr. Lardner, Professor Moseley, M. he Play, 



