﻿OF THE HINDUS. 263 



fcnown, those of the other planets are determined, ac- 

 cording to their periodical revolutions, by proportion. 

 As the sun's revolutions in a Mala Yi>g 4320000 are 

 to the moon's revolutions in the same cvcie S15333^> 

 so is her orbit 324000 Yojan to the sun's orbit 433 1500 

 Yojan-, and in the same manner for the cacshas, or or- 

 bits of the other planets. All true distance and mag- 

 nitude derivable from parallax, is here out of the ques- 

 tion ; but the Hindu hypothesis will be found to an- 

 s.ver their purpose in determining the duration of 

 eclipses, £cc. 



For the diameters of the sun and moon, it is directed 

 to observe the time between the npDearance cf the limb 

 upon the horizon and the instant of the whole disk 

 being risen, when their apparent motion is at a mean 

 rate, or when in three signs of anomaly ; then, by 

 proportion, as that time is to a natural day, so are their 

 orbits to their diameters respectively ; which cf the sun 

 is 6500 Yojan; of the moon, 480 Yojan. These 

 dimensions are increased or di .d as they ap- 



proach the lower or higher ap<is, in proportion as their 

 apparent motion exceeds or falls short of the mean, for 

 the purpose of computing the diameter of the earth's 

 shadow at the moon, on principles which may perhaps 

 be made more inteiiigible by a figure. 



Let the earth's diameter be fa=jrfc=cd j the dis- 

 tance of the moon from the earth AB 5 and her diameter 

 CD. By this system, which supposes all the planets 

 moving at the same rate, the dimensions of the sun's 

 orbit will exceed the moon's, in proportion as his pe- 

 riod in time exceeds hers ; let his distance be AE, and 

 EFG part of his orbit. According to the foregoing 

 computation also, the sun's apparent diameter/ i, at 

 this distance from the earth, is 6500 Yojan ; or rather, 

 the angle his diameter subtends when viewed in 

 three signs of anomaly, would be 6500 parts of the 



S3 



