Page:Mécanique céleste Vol 1.djvu/13

Rh attraction of spheroids, and make other alterations, on account of the improvements in the calculation of the attraction of an ellipsoid, first pointed out by Mr. Ivory.

The notes are adapted in some respects to the state of the elementary publications on scientific subjects in this country, and a greater number have been given, than would have been necessary, if the elementary principles of some of the methods, used by the author, had been in common use in our schools and colleges. They might in some cases have been abridged, by small alterations in the original work, but it was thought best to adhere strictly to the method of the author.

It may be advisable for a young person, in reading this volume for the first time, to pass over the eighth chapter of the first book, which treats of the motion of fluids, being rather more difficult than the rest of this volume; he may also pass over the fourth and sixth chapters of the same book. After reading the second book, which contains all the most interesting principles of the motions of the heavenly bodies, he can return with additional force, to these chapters, before entering on the calculation of the figures of the heavenly bodies in the second volume.

Since this work was prepared for publication, there have been printed in England, two translations of the first book, with notes, by Mr. Toplis and Dr. Young, which were seen before this volume was printed, and occasional use has been made of them. It is understood that Mr. Harte is now printing a translation, but no copy of it has yet been received in this part of the country.

The second volume of this translation is now in the press, and will be published in the course of the next year. These two volumes will finish the first part of the work, which may be considered as forming a complete treatise in itself. If it should be found expedient, the whole work will be printed, in five or six volumes, as soon as it can be done with convenience, taking sufficient time to ensure typographical accuracy, in the execution, and the whole will probably be completed in four or five years. This time has been considered necessary on account of the laborious occupation of the translator, which affords him but little leisure to attend to the revision and publication of the work.