150 On the Measure of 
different from the opinions and calculations 
of authors of the first reputation.”* 
It is true, Mr. Smeaton’s maxims agree 
with some of the results brought out by the 
common theory. His maxims, however, are 
by no means the most important conclusions 
which he has drawn from the results of his 
experiments; neither can 1 agree with the re- 
viewers in supposing that he considered these 
maxims to be inconsistent with the common 
theory. Ifit were admitted, according to the 
theory, that the pressure at the circumference 
of the wheel is always as Ax(c—w)” we can 
hardly suppose Mr. Smeaton to have been so lit- 
tle acquainted with the principles of calculation 
as-not to have been aware that the maximum 
effect must. consequently be as Axc*. The 
principle of the ws viva agrees still more 
remarkably with the common theory in cases 
of rotatory motion generated about fixed axes, 
as I have already observed at page 117. But, 
although the rotatory force of a body in motion 
is, according to the common theory, as the 
square of its velocity, [do not see why that 
agreement with the principle of the vis viva 
should be brought as an objection against it. 
The chief object in discussion is to ascertain 
* Philos. Trans. 1776, p. 457. 
