DEGREE. 
made from one alone, the difference in the refults would 
hardly have been fenfible. The length of the bafe on 
Mifterton Car was 26,342.7 feet. 
ther. 
whofe furface throughout its whole ex 
tent is quay | Gian with hiily 
‘© This ar sites oni the neceflary confequence whic aaa 
an operation 7 a ied fo circumfance idly 
{pot fixed on fo a place could be fuppofed ee from che 
efteets of oneal attraction in the adjoining matte 
“In fuch a country, therefore, a meafurement upon the 
moft ane ar arc oaut give the moft accurate conclufiun 3 
for the errors arifin from the oo here ecto like 
he difference of latitude between that place and Aber- 
deen, near to which that line cuis its parallel, is 4° 47’ 
nearly, 
‘But, however great the advantages attending fuch a 
length of arc might be, under the genera achepege ol ces of 
accurate obfervations 
ec would be found running, almoft every 
where, through : a country oe with hill-, confiderable 
both in magnitude and number 
* Under this confideration, I determined to meafure a 
portion of the meridian pr 
its extremities, as obfervations made there, 
in con ineiea with others at Greenwich, would enable me 
to make correétions of ade: of places given in our 
Butfer-hill from Dunnofe, 140.580.4 feet. 
former aa if on neceffa By fixing 
I had alfo the me 
nend of my 
okir aod Paris.” 
a the amplitude of the arc, a zenith fector 
was conftru@ed by Ramfden. This was the laft work of 
on which he had exerted all his talents 
o render it the firft of its kind. The radius of the feQor 
was upwards of eight ae ae the object-glafs of the tele- 
{cope four inches in dia 
The greateft part vy ‘the former of 1802 was employed 
by colonel M 
Ie was firlt erected at Greenwich, — at Dunnofe, 
Cliftom and pha tes a and fo ftars were obferved 
at each o , that dee can hardly remain a 
doubt of the ane pees being determined to the neareft 
fecond. It is true, we have me 
courfe of this 2 
{e€tors, which agreed ei aie very well with each other ; 
and yet were affected by fome common error of confiderable 
nag rade from ae ee pofition of the plane of the 
inftrument, either with refpe€ 
ed, both by ies artitt 
ne the ae. to avoid the poflibifity of fuch ana 
obfervatories of Greenwich ard Ble nei 
transferred upon the arc by, means of triangles, euteacd 
in the former {urvey ; and thus the latitudes of five different 
e dire€tions of the meridian 
elongati 
atic hae has euioaly been adopted a es the Englith 
furveys is the moft accurate that can be dev For this 
ind of areata the repeating circle is ak inferior 
. the pai 
The tations were connected by twenty-two tri- 
angles Pi iene (Vid. Plate VIII. jig. 69.) 
Phil. Tranf. for 1795, p. 501. 
7 
: Angles cor- 
No. of ‘ Obferved : Spherical ; IDs 
aisle Names of Stations. Angles. Diff, as Error. sera Diftances 
or w ” " u _ = Feet, 
I. Butfer-hill a é 46 12 22 1.99 76 12 21.5 
Dean-hill - - 48 4 32.25] —1.54 48 4 31.75 
Dunnofe - - 55 43 7 — 1.53 55 43 675 
180 0 1.25 5-0 mae te) ; 
er- hill. - - - T4HO5S0.4 
Dunnofe from es n-hill - - » 183496.2 
A Dean-hill - 1 62 22 48.751 ~1.37 62 22 47 
Butfer-bill - - - | 48 23 41.5 | —1.23 48 28 40 
Highclere - - 69 8 35 —165 69 8 33 
180 0 5.2 4.07 +1.18 
| ; : Butfer-hill - : = 156122.1 
Dean-hill from | Fiighelere - - - 125084.9 
