C 330 J 
App. time. 
h 
/ 
// 
Firft external contadl, June 3, 
7 
12 
56 
Total ingrefs ■ ■■ ■■■ ■■- 
“ 7 
31 
52 
Middle 
■ 10 
23 
04 
Beginning of egrefs — — 
14 
16 
Laft contadl ■ 
13 
33 
1 1 
Hitherto we have had no regard to parallax, and 
the above times are fuch as would be obferved from 
the earth’s center. To the Britifh ifles, and to the 
neighbouring parts of the continent, the effedl of 
parallax is nearly at a maximum, and will confider- 
ably accelerate the times of external contact and in- 
grefs. If we fuppofe the fun’s parallax on the day of 
thetranfit =8^', 7, the horizontal parallax of Venus 
from the fun will be 21", 87; and the times of the 
external and internal contadts vifible in England will 
be accelerated by the joint clfedts of parallax, both in 
the diredtion of the planet’s path and perpendicular 
to it j the former by 7'. 09" ; the latter by 7'. 12'^ 
And therefore Venus will be feen to touch the fun’s 
limb at 7^. 5'. 47", more than an hour before the 
time of fun-fet ; when the apparent altitude of the 
planet above the horizon will be about 8 degrees : 
and the total ingrefs will happen at 7*'. 24'. 40''', 
when the planet’s altitude will exceed 5 degrees. 
If the fun’s parallax fhould be one fecond larger than 
we have fuppofed, or 9'', 7, the time of ingrefs will 
happen at 7^. 23'. 51". 
Thefe times are not here given with any great de- 
gree of confidence : but as the errors in the planet’s 
orbit will, in June 1769, be nearly the fame with 
thofe 
