1804.] Proceedings of Learned Societies. 165 
fouth, And the zenith diftance of Between Arbury Hill and gos acy 
this (tar, at the fame period, at the fta- Greenwich......-. of 44! 48".19 
tion Dinnofe, was 0° 53! 56.6 63 north. Between ear and Blen- ; 
Therefore the ‘difference of latit tude be we Mieis ee ee pee Ti Eg, 29509 
tween Dunnofe and Blenheim was 1° 13! Hons Pah Sacell  gieigge ON 69 
The. latitude of Dennofe is 
that oF Greenwich being 
28’ 40", as difference 1s 
OF5 1, 9a". 80) Hence 50° 37! 8.25 + 
Po he 8G y0G, = kin 5o; 2744.0, IMUMADe 
the latitude of Blenheim, within a {mall 
part of a fecond of the truth. 
Mr. Mudge found the fubtenfes in the “ 
heavens, of. the. different parts of his 
terreftrial, arc as follows; 
19".69. 
50° 37! 8N.ar 5 
taken at BS 
Between Dunnofe and Clifton 2° 50’ 23.30 
Between Dunnofeand Arbury . 
Taking the diftance of Blenheim Ob- 
fervatory from the perpendicular to the 
meridian of Dunnofe at 446458 feet 
(fee Philofophical Tran{ actions 1800); 
and the parallel to the perpendicular at 
‘Dunnofe from that obfe:vatory, where it 
cuts ne meridian of the former, being 
about 34 of a fecond in latitude north a3 
the latter, therefore Mr. Mudge takes 
the difiance of Blenheim north ‘of Dun- 
nofe to be 446498 feet ; hence he obtains 
the following terrefirial arcs, from which 
Sh MOE ys “Ngee 3° ae he computes the lengths of the fever cal 
MS og tlds Saleen! 1,14 3.40 degrees; for by dividing the ares by 
Between Dunnoie and Green- _ their correfponding - celettial ones, and 
8 eRe Ciel ee ee © §t 37.39 afterwards multiplying the quotients by 
Between Greenwich and Clif- 3600", we get the lengths of the dee 
ROR es ences cL r 58 $1.59 grees. 
Ares. \ Feet. Fathoms. 
s. Dunnofe and Clifton 1046337 ae 223 7 60820 
2. Dunnofe and Arbury Hill 586320 Shey dome, 60864. 
3. Arcbury-Hill and Clifton 450017 | is i | 60766 
4. Dunnofe and Greenwich 913696... ; 3 oe eS age 60884. 
5. Greenwich and Clifton 7226410 = vo ™ = c 60794. 
6. Arbury-Hill and Greenwich 272624 & NPE 2 | 60849 
7. Dunnole and Blenheim 44.498 Sa 2.2 60890 
8. Blenheim and Clifton 589839 pes BNBE So |. Ge7iag 
Taking the latitude of Greenwich at 
given, the latitudes of their middle points 
the feveral arcs nove 
and, with the lengths 
51° 28/ go” from 
are readily found 5 
of the degrees, when properly- arranged, will ftand as follows: : 
Arbury Hill and Clifton 
Blenheim and Clifton 
Greenwich and Clifton 
Dunnofe and Clifton 
Arbury- Hill and Greenwich 
Donnofe and Arbury-Hill 
Blenheim and Dunnole 
Dunnote and Greenwich 
PrEEREEI 
From this meafurement it appears, that 
' the length of a degree on the meridian in 
latitude 52° 2’ 20” is 60820 fathoms, 
fuppofing the mlisle are fubtending an 
angle of 2° 50’ 23.38 in the heavens, 
and a diftance of 1036337 feet on the 
furface of the earth. 
The length of the degree at the middle 
point (51° 35’ 18”) between the fouthern 
extremity of the arc and Arbury-Hill is 
60864. fathoms, which exceeds the above 
by 44 fathoms. But this degree, ad- 
mitting the earth to be an ellipfoid, with 
the ratio of its axes as 229 to 230, fhould 
be about 10 fathoms lefs. 
‘ MontTuHiy Maa, No. 112, 
Latitude of imid- 
We points. Fathoms. 
G2 56 2D 8 | | COTO 
52 38 56.1 — 60769 
2.20 Sag. eee, COTO 
52 2 19.8 — 60820 
St 5t 4c “— 60849 
§r 95 18.2 — 603864° 
Gi 13, 10.2 — 60850 
Bi 2) 54.2 — 60884. 
Mr. Mudge is, however, perfectly con-. 
vinced of the general accuracy of his 
whele undertaking; and after carefully 
re-examining his books, he thinks it 
highly probable, that an error in the 
whole diftance of 197 miles, does not 
amount to more than 100 feet corre!pond- 
ing to 1” in the amplitude! of the whole 
arc, or even to half that quantity. 
From the Jate operations of the French 
Academicians it appears that the merido. 
nal diftance between Dunkirk and Barce. 
lona is 3527921 feet 5 the diftance between 
Dunkirk and Paris is 133758 feet; and 
the diftance between Paris ard :Green- 
ze wich 
