516 The British Association. [October, 
causing the drop to contract, and of oxidation of the surface 
outside the acid drop causing it to re-expand. 
Mr. J. R. Wigham read a paper on “ New Applications 
of Gas for Lighthouses.” The first part of his paper referred 
to the Quadriform Gaslight. Galley Head is a promontory on 
the coast of Cork, in the neighbourhood of which there had 
been several shipwrecks. The Commissioners of Irish 
Lights therefore determined to place upon it the most dis- 
tinctive and powerful light which they could obtain. With 
this view, and acting upon the advice of Dr. Tyndall, they 
adopted the Quadriform Group Flashing Gas Light. The 
power of the burner was obtained by a peculiar arrangement 
of numerous fishtail jets, and by suspending over the flame 
an oxidiser of talc, or some other material, by means of 
which the current of air was brought in contact with the 
most smoky part of the flame, rendering it not only smoke- 
less, but exceedingly white. The oxygen of the air was 
twice availed of ; first through the bottom of the flame, 
and secondly at the top, where its action raised to a white- 
heat a large quantity of solid carbon found there. The 
burner requires no chimney-glass. It was so constructed 
that the lightkeeper could increase the power of the light 
by five steps, accordingly as the state of the weather might 
seem to require. In clear weather 28 jets were used, and 
the number might be enlarged to 48, 68, 88, or 108. The 
changes from one to another could be very quickly effected 
by the use of mercurial joints. [The burner which was 
exhibited on the table was then lighted, and the five different 
degrees of illuminating power were illustrated, the effect of 
such an immense volume of flame being most startling in 
such a confined space.] It was well known that some 
“ fogs” are so dense that even the rays of the sun could 
but feebly penetrate through them ; but when the weather 
was merely what was called “ thick,” then it was that the 
mariner derived great benefit from such differentiating lights. 
The power of the burner would, of course, be very much 
increased by the use of lenticular apparatus, a specimen of 
which was before the meeting. [It may be here parenthetic- 
ally remarked that early in the day some amusement was 
caused by the facft that the rays of the sun shining through 
the lens, which faced the window, set the green baize table- 
cover smoking, and it had to be placed under cover.] If 
instead of using this ordinary lighthouse lens, which was 
designed and calculated to transmit the light of an oil-lamp 
4 inches in diameter and 3J- inches high, a lens made to suit 
his large gas-flame, which was 12 inches in diameter and 
