l Mr. Pickering’s Eulogy on 
and these have been brought together, and analyzed with vast 
labor, by Dr. Bowditch, from the Transactions of learned Societies, 
the works of individual authors, scientific journals, and every other 
accessible source of information within the range of modern science. 
The result of this laborious investigation, however, is not abso- 
lutely decisive of the question. Dr. Bowditch remarks, that the ob- 
servations, though made with the greatest care, differ so much from 
each other, that we cannot place great confidence in the result of 
any combination of them, unless the number of observations is very 
great; and it is, therefore, desirable to obtain many more than we 
now have, particularly near the equator, where the most remarkable 
variations have been found, But another remark made by him, on 
the result of the observations which we already possess, is singu- 
larly striking and interesting, as a proof of the minute exactness of 
modern science. He observes, that, instead of being dissatisfied 
with this result, we ought to feel some degree of surprise, that by 
means of the very small excess of the polar over the equatorial 
pendulum, which may be considered as a base line of less than a 
quarter of an inch in length, we can determine within a fraction 
of a mile, the difference between the polar and the equatorial radius 
of the earth. Dr. Bowditch adopts, as being very near to the true 
value, the ratio 335, which he has always used, and which was 
proposed by La Lande, in his Astronomy, forty years ago. 
This subject had been discussed by Dr. Bowditch more than 
twenty years previously, in a Memoir communicated to the Acade- 
my, to which I have already referred. The examination of the 
subject at that time was suggested by the republication of Rees’s 
Cyclopedia in this country. In the thirteenth volume of that work, 
containing the article Earth, he found that the editor had published 
the “elegant method” of computing the oblateness of the earth by 
the observed lengths of pendulums in different latitudes, as it was 
