262 Proceedings of the Royal Society. 
a single fibre of the silk worm to the extremity of an adjust- 
ing screw, which worked in the cap of the glass vessel enclosing 
the bar. A brass wire also passed through the cap for the pur- 
pose of placing the bar at right angles to the magnetic meridian 
previous to its being put into a state of oscillation. 
On the days devoted to the experiments on ship-board, the 
time of making 50 vibrations of the bar was determined in the 
centre of a meadow, of which the substratum was clay-slate, by a 
mean of 6 sets of experiments, the time being accurately regis- 
tered to quarter seconds. The instrument was then taken on 
board, and placed in succession at the different stations in the 
ship, and the mean of 6 sets of experiments determined at each 
station, with the same precaution as on land. The time, says the 
author, of performing the oscillations on shore, and at each of the 
assumed points in the ship, necessarily gave the magnetic in- 
tensity at each station in terms of the terrestrial intensity, 
which in this case was represented by 100. 
Thursday, March 4. 
William Wavell, M.D., and Captain Philip Parker King, R.N., 
were admitted Fellows. 
At this Meeting of the Society a Letter from Sir E, Home, ad- 
dressed to the President, was read, containing 
Some curious Facts respecting the Walrus and Seal, discovered by 
the examination of Specimens brought to England in the different 
Ships lately returned from the Polar Circle. 
The first fact stated by Sir Everard Home in this paper is, the 
analogy in structure between the hind foot of the walrus and the 
foot of the fly. In both there is a very similar apparatus for pro- 
ducing a vacuum, so as to enable the animal to proceed upon 
smooth surfaces against gravity by the adhesion of the feet thus 
effected, there being 2 cups in the foot of the fly, and one in that 
of the walrus for this purpose. Secondly, he notices the peculiar 
mode in which the bile in the walrus is collected in a reservoir; 
and thence forcibly impelled into the duodenum. 
