A Treatise on Plane and Spherical Trigonometry

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THE SECOND EDITION.

BEFORE the time of the first publication of the present performance, no work of a similar kind had appeared, in this country, which could be considered as partaking, in any degree, of the great discoveries and improvements which had been made, in the subject here treated of, within the last fifty years.

The author was therefore induced to lay before the public an additional treatise on this useful and interesting branch of knowledge, that should be more conformable, both in matter and method, to the present state of the science; and from the favourable reception it has met with, he flatters himself, that the undertaking has not been regarded as either useless or unnecessary.

A careful revision, however, of the several parts of the work, appeared to the author to be still wanting; and he has accordingly made such alterations and improvements in the present Edition of it, without materially departing from his original plan, as he trusts will render it still more deserving the public favour.

Among other things, of this kind, that might be

mentioned, nearly all the practical questions before given, many of which had passed, in the same state, from one work to another, for more than a century past, are here reproposed with new data; and in every case, where it was judged necessary, both the examples and the rules upon which they depend, have been carefully attended to, and reduced to their most commodious and approved forms.

The analytical part of the work, also, where the author first introduced to the notice of the English student, the many elegant theorems and formulæ, with which Euler, Delambre, Legendre, and other eminent mathematicians have enriched the science, is here considerably improved; and, though comprised within a short compass, will, it is conceived, be found to contain all the most useful and essential principles of this extensive and important branch of analysis.

Royal Military Academy,

Oct. 17th, 1812.

J. BONNYCASTLE.