% Drs Christison and Turner on the Construction of 
in London and elsewhere, that a necessity was generally felt for 
farther and more varied experiments, before a question in which 
such an immense capital was involved throughout the kingdom, 
could be held as definitively settled. 
A variety of circumstances, which it is not material to men- 
tion, having brought it under our consideration, we were natu- 
rally led to inquire, whence the singular discrepancies arose 
among the statements made by various scientific men of emi- 
nence. Two causes at once presented themselves to our notice, 
independently of a difference in the quality of the gases sub- 
jected to trial. On the one hand, it was probable that the means 
resorted to for measuring the intensity of light were not always 
sufficiently accurate ; and, on the other hand, it was evident, 
that the gases had been burnt by different experimenters under 
circumstances so different and so unsettled, as rendered it impos- 
sible their results could harmonize with one another. 
The former of these causes has been already made the sub- 
ject of public attention by a controversy, in which it has been 
our misfortune to hold a small share. We shall have occasion 
to allude to it in the course of the present paper ; but we shall 
be brief on the subject, as the form, which it has assumed in 
the hands of some of our opponents, renders it quite unfit to be 
brought before the Society. 
The latter cause of discrepancy, however, or the unsettled 
mode of burning the gases, soon appeared to us to be one of 
much greater consequence ; because, besides accounting for many 
of the differences alluded to, its examination obviously led to a 
practical result of no small moment, namely, the mode of burn- 
ing the gases, so as to give the greatest light with the least ex- 
penditure ; in other words, the proper construction of oil and 
coal gas burners. 
It appeared to us not a little singular, considering the prodigious 
amount of capital embarked in the gas-light companies (which, 
in London alone, according to Sir W. Congreve’s Report, drew, 
in the year 1823, a nett annual revenue of L. 300,000, Ann. 
Phil. vol. v. p. 412.), that no pains had been taken by these 
companies, or by scientific men, to determine the proper con- 
struction of the burners. In 1820, a few hints were thrown out 
