264 Mr. F. Waldo on Mr. Ferret's 
because it would greatly augment the quantity of vapour 
which would be available for snow. 
I shall next examine at considerable length Mr. Alfred R. 
Wallace's modification of the theory, as given in ' Island Life.' 
XXXVIII. On Mr. Heath's Criticism of Fen-el's Theory of 
Atmospheric Currents. By Frank Waldo*. 
IT is not astonishing that Mr. Heath should not have a cor- 
rect idea of the Theory of Atmospheric Currents accepted 
by the meteorologists of today ; but he was rather hasty in 
writing the criticisms on Mr. Ferrel's paper which have just 
appeared (in the July number of this Journal). 
I should do nothing more than refer the critic to papers 
from which he could obtain information, if it were not that an 
answer to his remarks is called for, not at all to defend Ferrel, 
because that is unnecessary, but to bring this matter a little 
more prominently before those who have read the criticism 
referred to, and who, if they accept it, will form an incorrect 
notion of the theory of atmospheric currents. 
In the first place the critic seems to be almost totally un- 
acquainted with the literature of the subject. It is true that 
he has apparently read Ferrel's first mathematical paper, and 
some minor papers in 'Nature ;' but he makes no reference to 
the other papers (more than sixty) on this topic which have 
appeared within the last twenty-five years. 
The whole subject is one that has been much neglected in 
England ; and, apart from the papers in ' Nature,' an article 
published by Mr. Daniel Vaughan of Cincinnati (U.S.) in the 
British-Association Report for 1859, and an article by Professor 
Everett, I know of no purely English writings which can be 
called at all important on the new dynamical meteorology. 
I will first take up some of the points touched upon by the 
critic, and make a few references to the literature. 
Dr. Haughton, as quoted on page 13, renders only due 
credit to Ferrel when he says that Ferrel has given a solution, 
which is in general satisfactory, of the problem of air-currents 
in his important memoir. This memoir is justly considered 
the first of the series of papers which followed, in which the 
atmospheric movements are deduced dynamically ; and it is 
recognized as the most important paper in the earlier history 
of the new meteorology — new as opposed to the Dovian. 
Mr. Heath says (pp. 14-15): — "A mass situated anywhere 
near the surface, but unconnected with it and unresisted 
by the air. if put in motion, will begin to move in fixed 
* Communicated bj' the Author. 
