[ 34 ° ] ’ 
Thus is the Sun’s parallax, on the day of the tran- 
fir, concluded to be = 8 r/ , 56, and that from three 
different modes of comparing together a great num- 
ber of observations varioufly combined; the feveral 
results fo nearly coinciding that to me it ieeir.s im- 
potlible, that the mean of them all can err _L. of a 
fecond, and that probably the error does not exceed 
^ 4 -er part of the whole quantity, as the great Dr. 
Halley had, many years fince, confidently prefaged*, 
and thereupon I cannot but congratulate cur age and 
nation, particularly this fociety on being enabled, 
through the roval munificence, to fend fit obfervers 
to the Cape of Good Hope, whole pofition affords 
the largeft bafe, and confequently the laieft founda- 
tion for the truth. 
P. S. M. Pingre, in his aforefaid memoir, feems 
to think that there muff be fome miftake in Mr. Ma- 
fon’s obfervation at the Cape, becaufe by comparing 
the obfervations of Jupiter’s fatellites made by Mr. 
Mafon at the Cape, with thofe made by M. Meffier 
at Paris, he finds the difference of longitude between 
thefe two places lefs by 1 ' of time, than between 
Paris and the obfervatory of M. de la Caiile at the 
Cape, and therefore imagines that Mr. Mafon’s ob- 
fervatory was to the weft of M. de la Cai lie’s. If 
M. Pingre had looked into the map of the Cape by 
M de la Caiile, be would have l'een, that, if Mr. 
Mafon’s obfervatory had been 1 ' of time to the weft 
* Ut junioribus noftris aftronomis, quibus forfan hrec obfer- 
vare, ob minorem aetatem, obtingere potdb, viam praemonftrem, 
qua immenfam fobs diftantiam, intra quingentefimam iui partem, 
rite dimetiri poterint. Ph. Tr. N. cccxlviii. p. 454. 
of 
