164 
a hitherto non-defcript kind of ftone, 
which is a mixture of feld{path and {chil- 
Jerfpath, at an elevation of nearly 4500 
feet above the level of the fea. This kind 
of ftone is fo powerfully magnetical, that 
it changed the direction of the needle at 
the diftance of four feet. It will take a 
very fine polifh, and, with refpecé to co- 
Jour, fomewhat refembles the Labrador 
ftone. The boundary of vegetation in 
Norway differs in different places, as do 
likewife the kinds of trees and. plants, 
which are capable of bearing a greater 
or lefs degree of cold. At the height of 
x006 feet, fome of the better forts of 
- fruit-trees thrive, and are productive. 
The pitch-pine (pizus picea LiN.) bears 
a greater degree of cold in Norway than 
- 
Proceedings of Learned Societies. 
[ March I, 
the fir (pinus abies Lrn.)}, the latter 
thriving only at the height of 2000 feet, 
which the former is found at an elevation 
of 3000 feet above the level of the fea; 
the birch likewife thrives at that height : 
but, at a greater height, Mr. Efnaark met 
with no other vegetable productions, ex- 
cept the betula nana, fome falices, and the 
juniper bufh, which, however, do not 
thrive at a greater elevation than 3200 
feet above the level of the fea. Barley 
and oats will indeed grow at the eleva- 
tion of from 1500 to 1800 feet, but only 
in fheltered valleys. At an elevation of 
from 1200 to 1300 feet, the night-frof 
does frequently great injury to the young 
Crops. 
PROCEEDINGS OF LEARNED SOCIETIES. - 
ROYAL SOCIETY or LONDON. 
NE of the moft important papers 
prefented to this learned body dur- 
ing the year 1803, was Major Mudge’s 
account of the meafurement of an arch 
of the meridian, extending from Dun- 
mofe, in the ifle of Wight, latitude 50° 
37/ 8” to Clifton in Yorkfhire, latitude 
53° 27' 31” carried on in the years 1800, 
1801, and 1802. Mr. Mudge was led 
to feleé&t Dunmofe for one of the extre- 
mities of his line, as obferyations made 
there, in conjunction with otheis at 
Greenwich, would enable him to make 
corrections of the latitudes of places given 
in papers formerly printed in the Tranf- 
actions of this Society. Befides, by this, 
he had the means of afcertaining the 
diftance of the Royal Obfervatory from 
the northern to the fouthern end of the 
line, and confequeatly, of conneéting it 
with the parallels of Dunkirk and Pa- 
ris. 
Dunmofe being fixed on, his object was 
to carry on the triangles, as nearly as 
poflible, in the direélion of its meridian, 
feleCting the itations, fo that their fides 
might be properly inclined to it, and 
of fufficient length. The northern ftation 
was to be brought as near the meridian 
of the fouthern one as pofiibte, and like- 
wile in the neighbourhood of fome open 
fpot of ground, proper for the meafure- 
ment of a bafe of verification. A ftation 
having thefe advantages was found near’ 
Clifton, a {mall viliage im the vicinity of 
Doncafter, and a level of fufficient ex- 
tent for a bafe, on Miiterton Carr, in the 
northern part of Lincolnfhire. At Clif- 
ton the direction of the meridian was ob- 
tained from numerous obfervations on 
the pole ftar, ar the times of its greateft 
eaftern and weitern elongations from the 
meridian. 
Having premifed thefe circumftances, 
Major Mudge gives a very accurate de- 
{cription of the Zenith Sector with which 
he made his obfervations ; with the man- 
ner of adjulting the infrument previoufly 
to ufe. The feétor and obfervatory made 
for its reception, were firlt erected in the 
Tower, and afterwards in the garden of 
the Aftronomer Royal at Greenwich, with 
a view of obferving the zenith. diftance 
of certain ftars, which were afterwards 
to be obferved at Dunmofe, to afcertain 
the latitude of that ftation. 
In cur account of this paper we can- 
not follow the worthy Major in his opera- 
tions, but we may obferve that he made 
ufe of every precaution to prevent the 
pofibility of error, and to obtain refults 
which, in future, might be depended on 
in all calculations. 
As the meridional line fixed on by 
Mr. Mudge was not far eaftward from 
the Duke of Marlborough’s obfervatory, 
he obtained from his Grace leave to make 
ufe of the obfervations he might have 
made at Blenheim, by which he had the 
means of afcertaining the lengths of the 
degrees on the meridian, at the middle 
points between Blenheim, and the two 
extremities of his arc. The mean zenith 
diftance of y Draconis at Blenheim, on 
the 1ft of January 1802, was o®% 19 23" 06 
F fouthe 
