128 Prof. Tail on Clcrk-MaxivelV s Law of Distribution, [sess. 
perpetually altering the velocity of each, the tendency is to some 
regular law of distribution of vis viva among the group. I am far 
from asserting that his paper (which, epoch-making as it was, is 
evidently a somewhat hasty and unmatured effort) is free from 
even large errors ; but it certainly does not contain such palpable 
absurdities as those now laid to its charge. 
M. Bertrand entirely ignores the fact that Maxwell was dealing 
with a u community.” And his comment on Maxwell might 
justly be retorted on himself in a slightly altered form. For he 
asserts that the x, y, z speeds are not independent, which is 
virtually the equivalent of the statement that when the latitude of 
a ship at sea has been anyhow determined, its longitude is no longer 
wholly indeterminate ! 
[July 6, 1896. Prof. Boltzmann, to whom I sent a proof of the 
above, requests me to add, on his part, as follows : — 
“ I have given expression to my high respect for Maxwell in the 
Prefaces to the two Parts of my Lectures on MaxwetVs Theory of 
Electricity and Light , and specially in the Motto to Part II. And, 
besides, I regard Maxwell’s discovery of the Law of Distribution of 
Velocity as so important a service that, in comparison, the trifling 
mistakes which appear to me to occur in his first proof are not 
worthy of consideration. The letters which I wrote to M. Bertrand, 
who was good enough to communicate them to the French Academy, 
had thus by no means the object of expressing my concurrence in 
M. Bertrand’s dissentient (abfdllig) judgment of Maxwell’s work 
on the Velocity-distribution-law. I wished rather to say that M. 
Bertrand was so much the less justified in this opinion because 
the one objection he was able to make had already been made by 
others, who agree in all essentials with Maxwell.] 
