49 ASTRONOMICAL Au» 
Thus it appears, that according to the obfervations of this. 
eclinfe made at Greenwich and Cambridge, the difference. of 
meridians between thofe places is 4" 44% 2921/'; fo that the 
time that was aflume for the difference was very near the truth. 
If the difference of meridians, thus deduced, is in any cafe con- 
fiderably different from that which was affumed, this refult is 
to be confidered as only the approximate difference, and is to be 
ufed a$ d new-affumed difference, from which deductions are to 
be made for the true. If the firft refult does not differ more 
thin two or three minutes from the affumed difference of meri- 
dians, the fame parallax in longitude and latitude may be ufed 
in the fecond procefs, which were found and ufed in the firt; 
becaufe the right afcenfion of the mid-heaven will not differ 
more than 6” or 8“ from the firft = the difference in the fun’s 
right afcenfion, which, together with the fmall difference in the 
moon 's longitude and latitude, will make fo trifling a difference Fo 
in her zenith diftance and parallactic angle, that the differei ice of — 
parallaxes will be inconfiderable. All, therefore, that is neceffa- — — 
ry to be done, in the fecond procefs, is to find the fan’slongitude —— 
and the moon's latitude for the approximate or new affumeddif- — 
ference of meridians, from whence, with the parallaxes, we — — 
muft deduce thé difference of longitude between the fun and — — 
moon, whereby the true conjunction will be obtained. 
For illuftration, let us take the foregoing obfervations of the 
folar eclipfe, and aflume 4* 42' 25“ for the difference of meci- 
dians between Greenwich and Cambridge. 
According to this affumption, at 11^ 39" 23^ A. M. when 
the ass: began at Cambridge, - i 
T 
