24 W. A. Norton on Molecular and Cosmical Physics. 
measurements to permit more than an approximate proof of 
its general accuracy. Every photometric observer must recog- 
nize its importance and the necessity in his observations of 
bringing the consumptions of gas and sperm to the agreed stan- 
Wu, 
To the consumer of gas the evident inference from the data 
here presented is that, where it is important to obtain a maxi- 
mum of economical effect from the consumption of a given vol- 
ume of illuminating gas, this result is best obtained by the 
use of burners of ample flow. 
Where a moderate light of equal diffusion is required over 
a large space, as in public rooms, it may be expedient to use 
numerous small jets; but when the maximum intensity ob- 
tai om a given volume of illuminating gas is desired 
intensity buruers of large consumption are plainly indicated. 
In the discussion following this paper, Mr. F. Stimpson, 
State Inspector of gas for Massachusetts, brought forward 
- some results of observations he had made upon Farmer’s the- 
orem (having been in correspondence with Prof. Silliman on 
the subject), and considered them in comparison with those 
herewith given. His conclusion was that while in many cases 
the theorem was closely applicable, in others it was not so. 
Mr. Stimpson’s discussion of the matter will very likely appear 
in an early number of this Journal. 
> 
Art. Il —Principles of Molecular and Cosmical Physics ; by 
| Prof. W. A. Norton. 
. 
zine, I showed that, by the introduction of a new hypothesis not 
portion of the propagated force is instan- 
mparting motion to the molecule, or atom, 
and is th srefore from this force. 
ae or aa ee 
