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which the reading of this paper has occupied, it is utterly impossible for me 
to follow out all the numerous points which Mr. Reddie has gone into ; 
indeed^ if I were to attempt to do so, I should keep you here until to-morrow 
morning. I will therefore beg your attention to some few remarks which I 
wish to make, and the rest must be left ; premising, however, that whatever 
is omitted to be answered, is not omitted because I think it unanswerable, 
but because it is impossible to take up your time with the answer. In the 
first place, I would beg leave to suggest to Mr. Reddie that scientific con- 
viction and scientific prejudice are two different things. I have the fullest 
conviction of the truth of the astronomical theory and the law of gravitation 
as commonly accepted. My judgment, applied in the best way in which I 
can apply it to the facts that are capable of observation, has been convinced 
that these theories are true ; and I trust that before I have concluded I shall 
have, in some degree, led you to suspect that scientific conviction is on our 
side, and scientific prejudice is monopolized by Mr. Reddie. (Laughter.) I 
dare say, ladies and gentlemen, you have often heard the story of the 
juryman who was never placed upon a jury but he invariably found 
that he had eleven obstinate men to contend with. (Laughter.) With 
regard to some of the preliminary observations of Mr. Reddie, I may 
say that I happened to be at the meeting of the British Association 
to which he alluded — and I have always been rather an active attendant 
at section A — and I beg leave to inform him, with all due deference, that 
his paper in 1862 was not declined because the Newtonian theory was 
attacked, but because it was the opinion of the committee of that section 
that the attack was really not worth defending, and because we did not feel 
disposed to be accessories before the fact to Mr. Reddie’s following the plan 
of the “Derby Ram,” in Punch, running his head against a wall. Now, 
with regard to the problem of the three bodies, Mr. Reddie has alluded to 
the strange assumption — that is the lunar theory — that the calculation is 
based on the supposition of the earth being at rest, and the moon moving 
round the earth, and the apparent motion of the sun round the earth. With 
regard to all such points, it may be said that there are many physical facts, 
amongst others, the actual motion of the moon in space, that are beyond the 
reach of mathematical analysis. In order to reduce the lunar theory to a 
differential equation it is necessary to assume that the earth is at rest (hear 
hear), and that the apparent motion of the sun round the earth is a real 
motion, and. that the apparent motion of the moon is a real motion 
also. And I maintain that that or any other hypothesis is legitimate 
unless it can be shown that the effect of that hypothesis invalidates the 
results which are ultimately arrived at. Because, with regard to the motions 
of the moon, you are first obliged to suppose that the moon is influenced by 
the attractions of the planets, and an immense variety of mechanical circum- 
stances, which you cannot put into the calculations all at once. You are 
obliged to assume that some of them do not exist ; and having attained the 
result which the analysis can bring you to, it is then necessary to ascertain 
the alterations which it is necessary to introduce, in order to take in the 
