the Trigonometrical Station on Rumbles Moor, &c. 193 
In a third attempt an intermediate accessible station was se- 
lected, and ald the angles reciprocally observed. The mean of 
the several methods, as appears from the subjoined statement, 
is 275°3 feet. 
Sum of the two distances. 
By reciprocal observations (12430 feet).......++, 275°6 
By object No. 1 o% /oG17 922 feet), .. «eisai Shard 
| re Qh eosin) GRGSD Meet) ) «5,5 sesid-e 27950 
Dos.» : 3 pe (15457 feet) vevecine +s 274°8 
Mean i a “, Me ae 275°3 
Canal above basin at Liverpool ait ee 63:0 
Basin above low water ae ee ee 54:0 
Height of observatory above the Irish sea... 392°3 
Difference of altitude of Rumbles Msor 926 feet 
and the Observatory by levelling .. 
Do. by reciprocal observations with the 927 feet 
horizon sector be HA os ; 
As the measurements of the locks do not exactly correspond 
with the statement in Dr. Rees’s Cyclopedia, I must, in candour, 
furnish the comparison. 
Dr. Rees. Measured. 
Feet. Ft. In. 
30 29 5 
279. i ieson VA 
RAL 54 5 
67 68 4 
se at the tunnel near Colne above the 431 432 1 
asin at Liverpool .. as 
Fall to E. Morton aA a 150 142 11 
281 289 2 
Fall to the river Aire as Af ~- 260 269 2 
21 20 
Mr. Priestley, in his plan of the canal, states the altitude at 
22: feet, and that of the basin at Liverpool at 56 feet 13 inch 
‘ above low water, or four feet more than it is given in the Cyclo- 
edia. 
, At Pendle Hill, September 24, 1821 (half an hour after the 
sun had passed the meridian) the sea in the direction of a wind- 
mill east of Lytham (or W.S.W.) was observed to be depressed 
53’ 54”. The instrument was 10 feet high, and the distance 
(by the map, corrected by the trigonometrical station at North 
Meals near the windmill) will be found to be 145,970 feet. 
Hence the ground at Pendle Hill was 1823 feet above the sea, 
to which add the fall to low water (?) for the correct altitude. 
It is stated at 1824 feet in the present list. 
Vol. 59, No. 287. March 1822, Bb In 
