result of a retrospective calculation. Whoever undertakes to investigate farther the chronology of the Hindoos, will derive great assistance from a Memoir of Mr. Marsden on that subject, in which he has explained the nature of their year and the several eras in use among them, with much ingenuity and precision. Philos. Transact. vol. lxxx. part ii. p. 560. NOTE LXVIII. p. 258. In the public buildings of India, we find proofs and monuments of the proficiency of the Brahmins in science, particularly of their attention to astronomical observation. Their religion enjoins, that the four sides of a pagoda should face the four cardinal points. In order to execute this with accuracy, they take a method described by M. le Gentil, which discovers a considerable degree of science. He carefully examined the position of one of their pagodas, and found it to be perfectly exact. Voy. tom. i. p. 133. As some of their pagodas are very ancient, they must have early attained such a portion of knowledge as was requisite for placing them properly. On the ceilings of choultrys, and other ancient edifices, the twelve signs of the zodiac are often delineated; and from their resemblance to those which are now universally used, it is highly probable that the knowledge of these arbitrary symbols was derived from the East. Colonel Call has published a drawing of the signs of the zodiac, which he found on the ceiling of a choultry at Verdapettah, in the Madura country. Phil. Transact. vol lxii. p. 353. I have a drawing of them in my possession, differing from his in some of the figures, but I cannot say in what particular place it was found. Sir Robert Baker describes an observatory at Benares, which he visited A. D. 1772. In it he found instruments for astronomical observation, of very large dimensions, and constructed with great skill and ingenuity. Of all these he has published drawings. Phil. Transact. vol. lxvii. p. 598. According to traditionary account, this observatory was built by the emperor Akber. The view which sir Robert took of it was an hasty one. It merits a more attentive inspection, in order to determine whether it was constructed by Akber or erected in some more early period. Sir Robert intimates, that none but Brahmins who understood the Sanskreet, and could consult the astronomical tables written in that language, were capable of calculating eclipses. P. Tiessenthaler describes, in a very cursory manner, two observatories furnished with instruments of extraordinary magnitude, at Jepour and Ougein, in the country of Malwa. Bernouilli, tom. i. p. 316. 347. But these are modern structures. Since the first edition of the Historical Disquisition was published, the Souriak Seddantam, or, according to a more correct orthography, the Súrya Siddhánta, on the principles of which I had observed that all the Indian astronomy is founded, has been discovered at Benares by sir Robert Chambers. He immediately communicated this valuable work to Samuel Davis, esq. who has favoured the world with a translation of several considerable extracts from it. The Súrya Siddhánta is composed in the Sanskreet language, and professes to be a divine revelation, (as Abul Fazel had related, Ayeen Akbery, III. p. 8.) communicated to mankind more than two millions of years ago, towards the close of the Sutty or Satya jogue, the first of the four fabulous ages into which the Hindoo mythologists divide the period during which they suppose the world to have existed. But when this accompanimentof fiction and extravagance is removed, there is left behind a very rational and elaborate system of astronomical calculation. From this Mr. Davis, has selected what relates to the calculation of eclipses, and has illustrated it with great ingenuity. The manner in which that subject is treated has so close an affinity to the methods formerly brought from India, and of which I have given some account, as to confirm strongly the opinion that the Súrya Siddhánta is the source from which all the others are derived. How far the real date of this work may be ascertained from the rules and tables which it contains, will be more clearly established when a translation of the whole is published. In the mean time it is evident, that what is already known with respect to these rules and tables, is extremely favourable to the hypothesis which ascribes a very high antiquity to the astronomy of the Brahmins. The circumstance, perhaps, most worthy of attention, in the extracts now referred to, is the system of trigonometry included in the astronomical rules of the Súrya Siddhánta. Asiat. Research. ii. p. 245. 249. It may be shewn that this system is founded on certain geometrical theorems, which, though, modern mathematicians be well acquainted with, were certainly unknown to Ptolemy and the Greek geometricians. It is with pleasure, too, we observe, that Mr. Davis has in his possession several other ancient books of Hindoo astronomy, and that there is reason to expect from him a translation of the whole Súrya Siddhánta. It must be added, that we also learn from the second volume of the Asiatic Researches, that some vestiges of algebraical calculation have been discovered among the Brahmins; particularly rules for the solution of certain arithmetical questions, with which it would seem that nothing but algebra could have furnished them. Asiat. Research. ii. p. 468. note, 487. 495. My friend, Mr. Professor Playfair, has examined that extract from the Súrya Siddhánta, which gives an account of the ancient Hindoo System of trigonometry, and has discovered the principles on which it is founded. It is with pleasure I announce, that the result of this examination will be communicated soon to the public, and will afford an additional proof of the extraordinary progress which the natives of India had early made in the most abstruse sciences. INDEX. Α ABUL FAZEL, minister to Akber, sovereign of Indostan, Agathemerus, his account of the island of Taprobana, 83. Agathodamon, illustrates the geography of Ptolemy, by maps, 321. Akber, sovereign of Indostan, his character, 214. 369. Albuquerque, Alphonso, the Portuguese admiral, seizes the |