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Mr. Eeddie.— No, no ; if equal, you could not have pulled it out ; and if 
the wall continued rigid, there would be no spring or reaction. 
Mr. Brooke. — But if there is no reaction when the string is fixed to the 
wall, I want to know where the reaction ceases. It is a distinction without 
a difference. (No, no.) I would only say, as a last remark, that nothing 
has ever impressed my mind with the conviction of the truth of the law of 
gravitation more strongly than the projection of eclipses ; in which, basing 
your calculations upon the law of gravitation, you can, months beforehand, 
state the time to a second, and the spot, within a small space, where the 
eclipse will occur. But the discovery of the planet Neptune from the dis- 
turbances of Uranus was a still stronger proof. I may mention that the 
planet Uranus was observed to have certain disturbances in its orbit motion 
in an unaccountable manner. M. Le Yerrier, of the Paris observatory, and 
Mr. Adams, in this country, set themselves to discover where and of what 
magnitude a body must be which could, by its attraction, affect this dis- 
turbance, and they both came to very nearly the same conclusion as to place 
and magnitude of this body. M. Le Yerrier communicated to another 
French astronomer where he supposed some body must be, and he looked 
for it in his telescope and found it. The result arrived at by our own 
astronomer, Mr. Adams, were unfortunately for a time laid by, and we in 
this country lost the merit of the discovery of the planet Neptune. But it 
was described inductively from assuming the law of gravitation to be correct, 
and finding where the body according to it must and ought to be placed in 
order to produce such disturbances ; and there the body was found. Nothing 
can convey a stronger conviction to my mind than such facts as these that 
the theory of the law of gravitation is substantially true, and that the prin- 
ciples advocated by Newton are also substantially true ; and that some of 
the difficulties which Mr. Reddie has laid hold of are only difficulties which 
have been necessarily introduced into calculations founded on these grand 
principles in order to bring the facts within the scope of exact analysis. 
(Applause.) 
Admiral Fishbourne. — I will detain the meeting only a few minutes 
while I refer to what Mr. Brooke has said about the effect of a breath of 
wind on the direction of a ball fired from a cannon 
Mr. Brooke. — Excuse me ; a man’s breath, not a breath of wind. 
Admiral Fishbourne. — That is only a difference of degree. Now, it has 
been established, by means of a very elegant instrument, that a round ball 
projected with only a limited velocity as compared with the motion of a 
heavenly body, rotates, and, because of its rotating in its progress, one 
side of the ball is receding from the wind and the other is approaching 
it ; and the result of that is that the difference between the action of the 
air on one side and on the other deflects the ball in its course. If that is the 
case even in our atmosphere, though it is not so attenuated as the medium 
the heavenly bodies traverse, there can be no doubt there must be a differ- 
ence in their velocities, when moving in a plenum and a vacuum 
Mr. Brooke. — Of course, every rifleman knows that it is necessary to 
