Astronomy.

iog

f Mercury inI Venus ■—

or y Mars —

S

ix

«

2S

*b,

* 6 - The

*4

14

18

7

21

42

25

29

*9

49

ir

00

54

54

54

54

! JupiterI. Saturn

r. °ve (Jet' 2 ^‘stance of the Planets from the Sun 33- n din» th^ t' !ne< ^ Rre reducible so Englijh Miles, by firstj^ont bv f a "h's Distance in that Measure • and this"at j 8 ' 'nding the Quantity of the Sun’s Parallax,^ter’a, "le Angle under which the Earth’s Semidsor\ Si,', EarS at 8un. Thus let S be the Centre^ r bit ^ g an d C the Centre of the Earth D EjF in her»? ^ci no . ’ the Angle D S C is that which we speak of,' ar th ann' at Un ^ er which the Semidiameter C D of theV Tos'" S at T ,e Sun.

"n'ety 0 f this Angle Astronomers have attempted0 {1 deters- ^ et .h°ds, but have as yet found none thata • er Vati 0 j lne !t exa hl!y ■, however, by many repeatediu a *t 12" ns os Dr. Halley it is found to be not greatertv ’') ha ^ ^ than 9". Wherefore 10Q (thejJ r ° ee!1 fixed upon as near the Truth, which/ n us tvi]] 6 contented with till May 26, 1761, whenQ tr ansit the Sun’s Disk, by which means the' eter <Din„j etTla n has shewn the Sun’s Parallax may be

a n.

ined

1 of i t' a g r e a t Nicety, viz. _ .

T 7 ^„ h l r Wh ole. See Phil. Trans. N° 348, abridged

18.' $’ ^ol. iv + .

^ the S??° f !stg therefore the Angle DSC= 10'3c/",

As

'C = 1

.7 to T^.angent ofRadius.

ifii J 1 ". SMe

ofegive,

of

Pl.'LIV.Fig, 2.

to within a 5codth

then fay,

DSC 10" 30'" = 5,706764D C = 1 = 0,000000qoP = 10,000000

ta 6 . -- , 8C - 19657,8 - 4,293236

>0 &• y, ° ^emidiameters of the Earth multipliedthe Sujl Ves 78631200 Englijh Miles for the Distance

Q. jvj

the p) 1 Distances only, but also the Diametersnets are to be investigated, by measuring their^ls in ' Ceth . apparent

‘he s '" a ‘ in 1 A at ® ve was wrote, both the Transits of Venus have passed ;hft "j? Es Pa ta p '’i an ^ t t' e >n 1769 ; but nothing certain relating tor,I1 Gt h av ‘: llas t " 1 " 1 determined as yet; the Observations on Ui«taVin g not been all received,