374 FP. £. Stimpson on Farmer's Theorem. 
equal, i.e., five feet per hour. But this penmar alone cer- 
tainly does not warrant the conclusion reache “That 
this theorem applies with equal force to the gars af sperm 
consumed by the standard candle as to the volume of the gas 
urned in equal times,” because the correction has not been 
applied to the candle either oom or in any other observation 
given in Prof Silliman’s paper. 
The confirmation obtained by experimenting upon Peytona, - 
Albert and Wollongong gas depends upon the assumption 
that the true candle power of a rich gas can be obtained by 
ne it in definite meeapan ness another gas whose illu- 
minating power is known, an cing from the observed 
candle power of the deatice: the wi 8 power of the rich gas ; 
until this assumption has been proved to - correct, it is of 
course useless in establishing Farmer’s Theorem. 
The next proof offered is drawn from a ‘etnies statement in 
Sugg’s Gas Manipulation. Prof. Silliman says, “ By this state- 
ment the burner in question produced from five cubic feet of 
gas exactly 15 (14?) candle power, but when reduced to 46 
cubic feet consumption the candle when ‘corrected to the 
standard quality of gas by. proportion ' was only 11°93 candles. 
The values of the ‘correction’ referred to can only be conjec- 
tured, but assuming that the observation made the uncorrected 
rendering 11:32 candles (a very probable quantity), we find that 
the law of we bi ae of consumption then makes the ratio as 
for the gas by reversing the wr used, 
armer’s Theorem 
be BART: expressed bee the ratio 45? : 10 73 3=5?: 13-997=14. 
The last proof offered is drawn from Audoin and Berard’s 
ee But after several fruitless efforts to obtain the 
esults, as given under the head of ‘ Tstenaitive by law of the 
Saar of ‘oranda I am forced to conclude that these 
figures are incorrec ugh some circa: 4 applying that 
law. The two hie referred to may be found in oe author's 
Ay a memoir on pages 439 and 421 © Annales de Physique 
himie, vol. Ixv, 1862. In these experiments they com- 
pared the burning of two batwing burners at different rates oF 
consumption, with a “‘ Bengel Argand ” whose rate of consump 
tion was nearly constant. The first three columns of the table 
below give their experimental data. 
