﻿2£2. ON THE ASTRONOMICAL COMPUTATIONS 



sixth, or in the perigee, in sama ; in the ninth 

 sign, in vlshama ; anr* in the twelfth, or the apogee, 

 in sama. The ' ... utgrees, or circumference of 

 the epicy ' soma are, of the sun 14 ; mvishama 15° 

 40'; ul che moon in sama 3 2°; in vlj/tama, 3i°4o ,- ' 

 the difference assigned -tcy^h between sama and imh- 

 ama, 20 . 



To illustrate these matters by examples, let it be 

 required to find the equation of the sun's mean to 

 his true place in the first degree of anomaly. The 

 sine of i° is considered as equal to its arc, or 60. — 

 The wrcumference of the epicycle in sama, or the apo- 

 gee, is 14% but diminishing in this case towards vish- 

 ama, in inverse proportion to the sine of anomaly. — 

 Therefore, as radius 3438 is to the differenr e between 

 sama and vishama 20', so is the sine of anomaly 60' to 

 the diminution of the epicycle in the point of anomaly 



propofed, zc" (= °'^ ) which, subtracted from 

 1 4°, leaves 13 59' 40". Then, as the circumference 

 of the great circle q6o° is to the circumference of the 

 epicycle 13 59' 40", so is the sine of anomaly 60' 

 to its correspondent sine in the epicycle h c ; which, 

 as was observed, is considered as equal to Im, or 

 true sine of the angle of equation 2' 19" 56'" 



(== * 3 5 l. o ), which, in the Hindu canon of sines, 

 lis the same'as its arc, and is therefore the equation of ^ 

 the mean ro the true place in \\ of anomaly, to be ad- 

 ded in the first six sines and subtracted in the last six. V 



For the equation of the mean to the true place in 

 C 14' of anomaly. The sine qj^ 5 14' is 31.3' 36' > 



8" and ^iili^^^^^ , = i>9}tobeded^ted * 

 from the faruVhi degrees in sama. — 14° 1 49"= 13 58' 



- — I2 9 59 me 

 %f the angtefSD^equariorv which is equal 10 its arc. 



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