Dr. Bowditch, President of the American Academy. hi 
given by La Place in his Mécanique Céleste, but had allowed the 
application of the formulas to numbers to remain nearly as in the 
original work, —in which there was a material error, — and that 
additional mistakes had been committed by the author of the article 
itself. Dr. Bowditch justly observed, that as the Cyclopedia had 
an extensive circulation in this country, he thought it proper to 
notice these errors, in order that “currency might not be given to 
incorrect ideas on the subject” ; and, as an additional reason, that by 
making the correction in question, we obtain from the observations 
of the pendulum a result much more conformable to those deduced 
from other methods. He then, in the same paper, points out the 
errors in the results, and their sources; to which I have already 
directed your attention. 
The third volume of La Place’s work contains, as before stated, 
the particular theories of the motions of the heavenly bodies ; first 
giving the theory of the primary planets, and then that of their 
respective satellites ; beginning with our own, the Moon, which 
occupies a large space. Dr. Bowditch’s annotations on this volume 
are of the same important and useful character with those on the 
preceding parts of the work; but time will not permit me to refer 
to the different topics discussed by him. I may, however, be 
allowed to mention, that one interesting and important subject, 
which had previously come under his notice, is here more particu- 
larly considered; I mean, the effect produced upon the motions of 
the planets and their satellites by the resistance of an extremely 
rare ethereal fluid; to which I have before directed your attention, 
when noticing this part of the original work. Dr. Bowditch has also 
made a most valuable addition to this volume, — an Appendix con- 
taining a full view of the different modern improvements made in 
the modes of computing the orbit of a planet, or comet, moving in 
an ellipsis, parabola, or hyperbola; with the methods of computing 
