DECLINATION. 
1806, Sept. r. D) UL. Zen: as ; 38° 48! 32".3 
Error of collimation : F +2, 
Additional corre&tion : .- +1 
38 48 36.2 
Refra&ion ‘ ° . ‘ 45.1 
oo 38 49 21.3 
Parallax in altitude a . 34 36.2 
i 38 14 45.1 
Semidiameter . : : . 15 8.8 
; . 38 29 53.9 
Latitude of Greenwich : : ° 51 28 40 
Declination of the moon : - 12 58 46.1 
Zen. dift. of ) 38° 42' 91” 
Diminished by angle of 
the vertical wih radius 10 3 
38 39 18=9.7956278 Log. fine 
Log. of 55’ 24”"=3324" ==3.5210030 
Part. in in eS a" =3.3172888 
a 30” and fem. diam. 15’ 8".8 
Diminifhed 6” 24=hor. par. He Greeowich, 
55 ela a 39 1 36=par* in 
When a ftar whofe declination j is well ae and nea rly 
on the fame parallel with the moon, has been obferved, it 
will perhaps be soe . deduce the ance — the 
moon from a comparifon with the ftar, as in 
34) 3 
Equatorial parallax 
nt 
Lxample.—ca peeiucl was 38 obterved the fue day, oe its 
zenith gg . 38° 44! 58".9 
Refra - & 44.8 
Conedlion as in the laft cua . 3-9 
Zen. diftance correGted : 38 45 47-4 
Zen. diftance of the moon ‘ ; 38 29 54 
— of declination between ” and ° 
° a ° oO 5 33:4 
Dictation of ; ' ‘ 12 42 57.4 
Declination of the moon ; . ; 
12 58 50.8 
Declination Jan. 1800 912° 43’ 4” 
Preceffion in fix years o 0 18.6 
12 42 42.4 
Prec. Aberr. &c. + 8.8 
Nat. ; - = +0.2 
Declination ‘ » 12 42 57.4 
On the Method of determining the Declinations of the Stars by 
Means of the repeating Circ 
It has been —— under the article aan saa this in- 
firument has not yet been received into fuch general ufe in 
” this cote as on the continent, where i it aa almott f{uper 
eded every other of the kind. it ; Ht is but little 
known, though brought to the Seas povfeion by on 
of our firft artifts. Perhaps we have recei 
e recel nfavourable 
imprefiion of it from the accounts jist Rasen to us 
by the French aftronomers themf{elves, from which we were 
led to fuppofe io it fee aati an ingenious contrivance to 
obviate the errors of & inftrum 
ae etic to any inftrument of its fize now in ufe 
If the of the itis ates be placed in the meridian, 
altitude, azimuth, and tranfit inftruments, and are fo well 
contrived to anfwer thefe feveral purpofes, that no facrifice 
b 
Verification of the repeating Circle. 
- To make the axis of vifion of the telefcope parallel 
the plane of the circ Peparaee to 
C 
what i is marke 
on the micro- 
meter wires, - the other half by the tangent {crew of the 
aaa circ 
. To pare the plane of the circle ina tiue cereal po- 
fition, 
This a ara is very effential when zenith diftances a 
intended to be taken the greateft poffible ecitien, 
u 
its true po This verification ae 
hikewife bs secomplie by Tafponding a plumb line on the 
back o But oe aries method 
he back of the 
lowing manner 
Sele& an oe of confiderable altitude, as a ftee eple o 
neighbouring chimney, obferve fome well-defined part in ity 
oth dire€tly and by refleGtion in a faucer, ofoil or treacle. If 
ae fa e object, be pinay sarin ie 3 the vertical wire 
le will be very exaétly 
pte and the level ae be then auld, and: fhould be 
occafionally — by the fame method. 
o place the horizontal wire in its proper pofition,. fo 
that tit may be parallel to the sca when the circle ig ver= 
tical, adjuft the azimuth circle, and bring the repeating 
circle to its vertical pofition ; bie fome well defined = 
ontal 
A 
