PREFACE.
The subject of the present essay was undertaken many years ago; but owing to a variety of causes, which could not be foreseen, its publication has been delayed much beyond the time that was originally intended. The first was, that I found it difficult to obtain any correct information respecting the ancient astronomy of the Hindus, by reason of all the. ancient works having been purposely destroyed or concealed, since the introduction of the systems now in use. I was therefore induced, by way of saving time, to lay before the Asiatic Society in A. D. 1799, a paper "On the antiquity of the Surya Siddhanta, and the formation of the Astronomical Cycles therein contained," intending to follow it up with the present essay, as soon as the necessary facts and data that I was in search of could be obtained. My paper on the antiquity of the Suiya Siddhanta was published in the sixth volume of the Asiatic Researches; and I was in great hopes that
