Nat the Navigator. A Life of Nathaniel Bowditch. For Young Persons

by Henry I. Bowditch

Commentary continued; second volume.—Discussion between the English and French mathematicians; Dr. Bowditch’s criticisms.—Errors in La Place in regard to the earth, &c.—Third volume; motions of the moon.—Fourth volume; many errors discovered in it.—Halley’s Comet.—Curious phenomena of capillary attraction.

CRITIC OF IVORY AND POISSON.

“I HAVE GOT IT!”

In the second volume of the Commentary, Dr. Bowditch makes very copious notes, in which he shows a perfect knowledge of the works of the chief mathematicians of Europe. He stands as critic between two of the eminent men of science of that day—Messrs. Ivory and Poisson, the former an Englishman, the latter a Frenchman; and in reference, likewise, to a difficult subject, namely, the revolution or the turning of a fluid mass upon its own axis, as our earth does. He not merely agrees with Mr. Poisson, but, by a very simple illustration, proves the total inaccuracy of Mr. Ivory’s views. I well remember the earnestness with which he studied this subject. Day after day, he returned to the task of finding out some “simple case,” with which to prove to the satisfaction of others the truth of his own view. At length, when he did discover it, he jumped up in ecstasy, and, rubbing his hands and forehead with delight, walked about the library-room, crying out, “I have got it!”

Dr. Bowditch in this volume points out five errors or omissions made by La Place, some of which are very important. One refers to the form of our earth, and had been previously communicated to the Academy. There is another of some moment, relative to the time occupied in the revolution of one of Saturn’s rings, La Place having made it longer than was true.

Finally, on the subject of the motion of the earth about its centre of gravity, he points out an error, in which La Place gives to two numbers only one third of their true value.

OLBERS AND GAUSS.

In the third volume, occupied as it is with the motions of the planets and of the moon, and with all the phenomena accompanying these, Dr. Bowditch shows much learning, and his power of bringing modern science to the thorough study of any topic. As in the previous volume, he labors without fear upon subjects treated of with much earnestness by La Place, Poisson, and Pontecoulant, in France, and Plana in Italy.

On the theory of the motions of the moon,—a very difficult and interesting subject,—Dr. Bowditch makes very copious notes; and the volume terminates with an appendix of more than two hundred and fifty pages, in which he gives the history of modern astronomy, in reference to the calculations of the movements of planets and comets. In this he speaks of Olbers and Gauss. The former, from having discovered three planets since the beginning of this century, was called “The fortunate Columbus of the Heavens.” The latter was one of the most remarkable men in the world for the rapidity with which he was able to perform the most tedious and troublesome calculations.[13]