266 
MR. LUBBOCK ON THE TIDES. 
The second term agrees approximately with Bernoulli’s theory, as Mr. Whewell 
remarked. I consider that the first term was due to the variation in the interval 
between the moon’s transits, and it has vanished, or nearly so, in the present dis- 
cussion, because we have employed a different transit. I account in the same 
manner for the first term in the moon’s declination correction of the interval, which 
Mr. Whewell deduced empirically from my former discussion, and which has also 
vanished in the present discussion for the same reason. This term perplexed me for- 
merly in comparing the results I obtained from Bernoulli’s theory with those I ob- 
tained from observation*, being far too great to be attributed to errors in the obser- 
vations, or in the mode of their discussion, so that I ventured to express an opinion 
that Bernoulli’s theory was insufficient. I discovered the true origin of this term 
about a year ago'f-. I conceive that the comparisons which accompany this paper 
establish the accuracy of Bernoulli’s theory nearly in as great a degree with respect 
to all the other corrections as with respect to the semimenstrual inequality, so that 
little remains to be gained by treating the problem more rigorously. 
One point at least, however, I think deserves further elucidation. The mass of the 
moon which would result immediately from the constant ( A ), which I have deduced 
from the London and the Liverpool observations, is greater than that which has been 
derived by other methods. Laplace appears to have arrived at a similar conclusion 
from the Brest observations ; but the arguments which he has used in order to remove 
this difficulty do not seem free from obscurity. 
* See Philosophical Transactions, 1834, p. 144. 
t See London and Edinburgh Philosophical Magazine, December 1835. 
ERRATUM. 
Page 224 , for (p — 15° read cp = — 15°. 
