DEGREE. 
tions, it is not probable’ a nae ee defletion exifted at 
Dunnofe ; as the deviation o ards the north, from a 
deficiency of matter pe on c} cae: would tend to d?- 
minifh the inequality between the leagths of the two degrees. 
This will be evident, on confideration, am therefore dif 
pofed to believe that the aoe = was drawa towards the 
fouth, from the ation of m t the northern ex- 
Dunnofe and Arbuay il were = from an 
ala caufe, the total arc mu too great, if taken at 
° go! 
.38, by about 8”, eddy oe an to 2” on each 
degree, A deve ion of 8” fro C true vertical is a large 
qua nor can the caufe oF it be affigned, un! lefs 3 it be 
alfo yee ied. that the matter producing t that d 
tends in a fouthern rae beyond Arbury-hill. 
robable, as above gash be fuppofed 
i nore than 10”; and 
aaa too from the effcéts of attraction in a fouthern direlion, 
e the deficiency of matter would lead us to belicve the 
net would happen. 
«Tam perfectly aware that it is poffible to ftate a cafe, in 
_ the plumb-line of a feétor 
vertical by fuch a quantity. Thus, for inftance, ina ky 
nee like the fouthern part of the i eearion if ‘ine inftru- 
ment were fet up adjoining the terminations of two [trata run- 
ning eaft and welt, o chalk, and the ee of much 
aa materials, the ¢ 
ut, unnofe, — argument does not apply; nor is 
there tn to believe, from external appearances, that i 
wiil do fo, with Ber either to ia aes or the nerve 
extremity of the meridiona 
a was t - difcovery oe fee difagreement between the 
fubtenf e heavens, of the whole are, and its corre- 
{po otcer tenciral one, with thofe of its aa which le 
me to apply to his grace a shi of Marlborough, for the 
obfervations made at Blenhe y Draconis, or fome other 
7s com aaah ance meer my requeft is fhewn, 
to be ag aria as the are 
ained he as the obfervatory at Blenh 
ced from his ler s obfervations 
at the ane place, with the meridional ‘Giftanee 446,498 
feet, give 60,890 — for the length of the degree on 
the meridian i latitud 13" 5 which agrees nearly with 
f 
sl 
a 
the length of the toe at ae aaa point between Green- 
wich and Dunnofe. ever, under all contiderations of 
the means by which the rani 51 13’ has b ned, 
L am inclined to believe there is £ 6 
bere in it, 
or 7 saa a o about ocr in latit ude. 
a : eafured {pac ce bet ". obfi vatory 
between ae € 
e thal, from the fame mode of 
proceeding, make it = ee tt, the gee) tenor 
of the wan feems to prove, that the plumb-line of 
fouth at all the fta- 
d an opportunity of throw 
pai on this interciting fubjeCt. But me ridional Aree 
on in infular countries, are not f el 
jutt conclufions with regard to the different hace of the 
. 
would deviate from the true: 
degrees, as the as eeeatioas conduéted in p'aces very 
remote from deep f 
oD aaa of the French academicians it’ 
that the meridional diftance between Dunkirk and 
Barcelona is 275.792.36 modules, the’ metre being 443.296 
lines of the Petu toife = 01259053 7th part of the module, at” 
the temperature of mestin . This mer: ridional dittances 
therefore, converted into Eenglith feet, 18 3.527.921, 
appecrs, 
dittance betweea Danki - and Paris is 133 oo feet, and 
the diftance between Paris and Greenwich is = 963 954 
feet 5 therefore, 850,196 ne is the cdilance between Greea-~ 
wich and Dunkirk. The dit be Leake Greenwich 
and Cuifton 1s 722.6, ect 3 henee, ev 1.958 ees is ce 
meridional diftance between ee oe Barcelon 
latitude of Barcelona is 41° 2:/ 46".8; the eee of 
Greenwich is 51° 28’ 40"; and it to this latitute we add 
¥Y 51”.59, the are between Clifton and Greenwich, 
r the latitude of Clifton: 
= 
rf te) 
otk 
p the . With this 
difference of nti de, andt caborewmentioned diftance, we 
fhall get 60.795 fa thoms, for the mea 
on the earth’s ue in latitude 47 al The latitude 
rile : . "; this, with that of Clifton, gives 
4° 37 16".59 fo a ee between their parallels. ‘lhe 
needed ieee 1,636,595 feet; hence, 60,825 fathoms 
is the length of the degree in eee 51° g’. 
Of the trigenometrical Operations in France, fince 1790. 
While this great work was elie on in England, a fimi- 
ar one was aay in France, and ona larger {cale, as 
n that country nee 1 at "Du nkirk, and e 
ond the a ontiers to Barcelona in Spain. he ol 
obtain a ftandard 
fome permanent quantity afforded by natu Mar ned 
men nat advocates for taking the len - of the aaea 
asa ftan ; but after much deliberation, it was refolved to - 
adopt ae mn millionth part of the quadrant of the meridian - 
for the unit, which was to be called a metre, and from this. 
all other sre wae to be derived. See Measure. 
To obtain this ftand 
feries arene tions, 
earth in a more fatisfaCtory manner than had hitherto 
been aoe and preparations were made for again repeating the - 
whole procefs for the meafurement of an extenfive arc o 
the meridian 
The cok remarkable difference in the mode’ of condu&te - 
e eee one 
shee circle of 
e€ ie all that is 
{urveys, pie ca nee will perm 
riority of the theodolite contifts ini 
of its telcfcope, ~ the ae with nN ‘ll azimuthal 
angles are obferved with it, without any correction 5’ as it 
combines all the peer ure tranfit inftrument, the pole 
ftar can be e brought to the — without ate a 
and its yest e direction 
neal ee in a manner "infty more exact t 
can be done gem are sere circle. Oa 
the ocher ca, ar fae initrument “fupplies the place of a 
zenith 
