136 REMJRKS on the 



their love of fcience : Hulagu reftored Aftronomy in Perfia, 

 and Ulugh-beigh, by an effort ftill more fingular, eftabliflied 

 it in Tartary. In the mean time, having pafled with the Arabs 

 into Spain, it likewife found, in Alphonso of Caftile, both a 

 difciple and a patron. It was carried, foon after, into the north 

 of Europe, where, after exercifing the genius of Copernicus, 

 of Kepler, and of Newton, it has become the moft perfedl 

 of all the faiences. 



2. In the progrefs which Aftronomy has thus made, through 

 almoft all the nations, from the Indus to the Atlantic, there is 

 fcarce a ftep which cannot be accurately traced ; and it is never 

 difficult to determine what each age, or nation received from 

 another, or what it added to the general ftock of aftronomical 

 knowledge. The various fyftems, that have prevailed in all 

 thefe countries, are vifibly conneded with one another ; they 

 are all derived from one original, and would incline us to be- 

 lieve, that the manner in which men begin to obferve the hea- 

 vens, and to reafon about them, is an experiment on the human 

 race, which has been made but once. 



It is, therefore, matter of extreme curiofity to find, beyond 

 the Indus, a fyftem of aftronomical knowledge that appears to 

 make no part of the great body of fcience, which has traverfed, 

 and enlightened the other countries of the earth ; a fyftem that 

 is in the hands of men, who follow its rules without underftand- 

 ing its principles, and who can give no account of its origin, 

 except that it lays claim to an antiquity far beyond the period, 

 to which, with us, the hiftory of the heroic ages is fuppofed to 



extend. 



3. We owe our firft knowledge of this aftronomy to M. la 



LnuBERE, who, returning, in 1687, from an embafty to Siam, 

 brought with him an extradl from a Siamefe manufcript, which 

 contained tables, and rules, for calculating the places of the fun 

 and moon *. The manner in which thefe rules were laid 



down 



* Mem. de I'Acad. des Sciences, torn- 8. p. 28 1. &c. 



