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88 Mr. lvory on the Theory of the Figure of the Planets. 
In a paper printed in the Philosophical Transactions for 
1824 I have investigated the conditions of the equilibrium of 
a homogeneous mass of fluid, and have applied them to de- 
termine the figure which it will assume when it is urged by 
the attraction of its particles and a centrifugal force caused by 
a retation about an axis passing through the centre of gravity. 
This is the first general solution of the problem that has been 
deduced from the principles of hydrostatics, without having 
recourse to approximations, and without introducing arbitrary 
suppositions. It must be allowed, however, that the investiga- 
tion is in some respects not so simple as it might be made. 
But I propose to return to this subject, and in a particular 
work to treat the theory of the figure of the planets from its 
fundamental principles. 
Feb. 3, 1826. JAMES Ivory. 
N. B. In the Conn. des Tems. for 1828, M. Puissant, in a 
note at p. 220, notices a mistake in naming an angle I fell into 
in the solution of a geodetical problem inserted in the Philo- 
sophical Magazine for July 1824, and which is corrected in 
the same Journal for April 1825. The least attention to the 
solution would have shown M. Puissant that the import of the 
angle, which I have inadvertently called the true latitude, is 
fixed by the assumed values of the co-ordinates. Hence it 
cannot possibly be what I have said it is; it is the reduced 
latitude, and can be nothing else. There certainly is a mis- 
nomer; but the accuracy of the solution is not affected by it, 
because the meaning of the angle is determined independently 
of the name given to it. M. Puissant uses these words, “ J/ est 
aisé de voir que le calcul n’est pas fondé sur des considérations 
analytiques assez rigoureuses, puisque le theoréme qui en découle 
nv est pas parfaitement exact.” Now here M. Puissant is passing 
sentence without having examined the case. My solution is 
perfectly exact: it is deduced from the most rigorous princi- 
ples of analysis; although, in enunciating the theorem in ques- 
tion, I have inadvertently given the name of the true latitude 
to-an angle, which in the analysis stands for the reduced lati- 
tude, and can possibly stand for nothing else. In the pages of 
the same Journal I have made many observations relating to 
subjects treated of in the Conn. des Tems; and although it would 
excite no surprise to find all these discussions passed by in 
silence in that work, yet it is rather remarkable that an inad- 
vertence alone, substantially of no moment, and which has 
been corrected so long ago, is held up to public notice and 
carelessly misrepresented. Be 
mL. Further 
