[ r 65 ] 
ing making the proper obfervations, at the conjuncti- 
ons, quartiles, and oppositions, of the Moon with Mars, 
which will be the means of fupplying fuch obferva- 
tions, as may happen to prove abortive before the 
oppofition of Mars , and alfo, in cafe any of the 
obfervations to be made after that opposition ihall 
prove deficient, the obfervations may be carried on for 
a month or competent time afterwards. As a further 
fecurity againft difappointments, as well as cheque, 
it will alfo be advifable to make the proper obferva- 
tions, the night preceeding and fubfequent to thofe in 
which the quartiles, conjunctions, &c. happen j for, 
as the quantities will not differ considerably from thofe 
obtained on the days fpecified, with proper allow- 
ances they may he brought in fupport and confirma- 
tion of the former. 
In like manner, when Venus is moving towards her 
inferior conjunction with the Sun, as will happen next 
year, the fame obfervations may be made withrefpeCt 
to her ; and continued for a neceffary time, to get ob- 
fervations of the place of Venus ; viz. the firft, when 
the Moon is in conjunction or oppofition with Venus: 
a fecond, when the moon is in her quartile with 
Venus : a third, in conjunction or oppofition: a fourth, 
when the moon is in her oppofite quartile to the for- 
mer : and a fifth, agnin in conjunction or oppofition : 
the fame opportunity will alfo offer when Venus is 
moving from her inferior conjunction with the Sun, 
and becomes a morning ftar. 
In regard to the obfervation of Venus, it is remarked 
by aftronomers, that the is to be feen with a good 
tranlit telefcope, when file is within a few degrees of 
the Sun ; but, as fhe is three times nearer the Earth, 
than 
