LIEUT. DRUMMOND ON THE ILLUMINATION OF LIGHT-HOUSES. 395 
“ Exp. I. The first light exposed was the single Argand burner with a reflector. 
This was quite distinctly seen, and all the party admitted it to be a good light. 
After several minutes this was put out. 
“ Exp. II. The seven Argand burners were next shown, each in its reflector ; 
and this was manifestly superior to the first ; but how much so I cannot say, 
perhaps four times as conspicuous. Both these lights had an obvious tinge ol 
brown or orange. 
“Exp. III. The third light which was exposed, (on the seven Argands being put 
out,) was that behind the French lens; and I think it was generally admitted by 
the party present, that this light was whiter and more intense than that from 
the seven Argands, though the size appeared very much the same. 
“ Exp. IV. The fourth light was that which you have devised, and which, in- 
stead of the clumsy word ‘Lime’, ought to bear the name of its discoverer. The 
Drummond light, then, the instant it was uncovered, elicited a sort of shout of 
admiration from the whole party, as being something much more brilliant than 
we had looked for. The light was not only more vivid and conspicuous, but 
was peculiarly remarkable from its exquisite whiteness. Indeed there seems no 
great presumption in comparing its splendour to that of the sun ; for I am not 
sure that the eye would be able to look at a disk of such light, if its diameter 
were made to subtend half a degree. 
“ The next series of experiments was the most interesting and decisive of 
all. Each of the lights above enumerated, viz. the single Argand burner, the 
seven Argands, and the French lens, were exposed, one at a time, in company 
with your light, in order to try their relative brilliancy. 
“ First comparative Experiment. — The single Argand burner was first exposed 
to this comparative ordeal, and nothing could be more pitiable than the figure 
it cut. Many of the party could not see the Argand light at all ; while others 
could just detect it c away in a corner,’ as some one described it. It was also 
of a dusky orange tinge, while your light was of the most intense whiteness*. 
“ Second comparative Experiment. — The seven Argand burners were now 
substituted in place of the single light. All the party could now see both 
* To many, the rays from the brighter light appeared, when seen with the naked eye, to extend 
across and envelope the fainter light, though the perpendicular distance between them was twenty- 
five yards. 
