﻿284 ON THE ASTRONOMICAL COMPUTATIONS 



they should be made in sydereal time. A sy* 

 dereal day contains sixty dandas ; each danda, sixty 

 viculas ; and each v'icula six respirations, in all 2 1 600 

 respirations answering to the minutes of the equator. 

 A nacshatra day is exceeded in length by the savan or 

 solar day by reason of the sun's proper motion in the 

 ecliptic, the former measures time equably, but the 

 latter varies in its length from the inequality of the 

 sun's motion, and the obliquity of the ecliptic. The 

 aun's equated motion for the middle of the eclipse 

 was found 60' 24" ; and the oblique ascension for the 

 eighth sign from the vernal equinox, in which he will 

 be found at that time, is taken from the foregoing 

 table 343 pahs, or 2058 respirations. As the num- 

 ber of minutes contained in one sine 1800, is to the 

 number of respirations, or the arc of trwl equator in 

 minutes answering. to the oblique ascension of the 

 sine,' the sun is in 2058, as above, so is the equated 

 motion 6o' 24", to the excess in respirations of the 

 savan or solar day over the nacshatra or sydereal day 



a ° 58 ' l *£' 24 " = 69' 3''; which added to 21600' gives 

 the length of the solar day by civil account from 

 sunrise to sunrise, sydereal time 21669. 3 respirations. 

 From one-fourth of this deduct the ascensional dif- 

 ference, the sun ajLpg declined towards the south 

 pole, for the semi|P#nal arc; and add it for the 

 seminocturnal arc : the former is 4997' 19", and the 

 latter 5837' 11"; which may be reduced to da&kis or 

 Hindu hours by a division of 360. Hence half the 



d p v r> p v 



day is 13 52 $z, and half the night 16 12 52. 

 The whole day added to half the night shows the hour 

 counted from the preceding sunrise to midnight 



43 58 38, to which add the time at midnight unex- 

 pired of the purnima titlii, for the hour of the civil 

 day corresponding with the middle of the eclipse. 

 The hour from midnight to the end of the ptrmma- 



