142 Altitudes of Mountains, &c. 
Mean temp. of At the Obs. At Cowper Cross. 
4 obs. at 10‘0 in Dec.1820' 32-0 » 4°8 low" 
26 Jan. 1821 39-4 rs 46 
20 a Feb. 36:9 w 355 
20 a Mar. 44:3 i 4°7 
5 i April 453 3 4:2 
_ The observatory is 851 feet lower than the Cross, and bears 
E. S.E. from it with a distance of 132 miles. The ascent for 
the degree of the thermometer is equal to 198 feet. 
M. temp. of 1821. At the Obs. At Rumbles Moor. 
5 obs. at 11.45 to 13.15 Mar.13 525 6°5 low" 
15 10. 0 to 18. 0 — 30 47-5 7:0 
22 7.30 to 18.30 Apr. 5 45°0 4°6 
6 7.30 to 10.0 — 12 43:8 48 
9 6. Oto 10. 0 — 19 386 (mist & rain) 2: 
The observatory is 67,082 feet E.S.E of Rumbles Moor, and 
926 feet lower. Hence 185 feet for every fall of | ° of temperature. 
Mean temp. of 13 obs. at 10°30 to 12:30, July 30; at Ilkley 
Wells 57:2; at Rumbles Moor 2-8 lower. Rumbles Moor is 637 
feet above the Wells.—Ascent required 224 feet. 
Mean temp. of 4 obs, at 13.15 to 14.0, Oct. 29, near Ilkley, 
58.6; Beamsley Rock, 3.0 lower. 
Difference of altitude 1021 feet. 
Mean temp. of 12 obs. at 12.30 to 15.0, June 14, near Bol- 
ton, 57.5; Beamsley Rock, 1.7 lower. 
Difference of altitude 913 feet. 
Mean temp. of 2 obs. Aug. 20 and Aug. 31, at Kettlewell, 59 ; 
at Great Whernside, 7.5 lower. 
Difference of altitude 1573 feet (by barometer). 
Mean temp. of 4 obs. Sept. 11, 13.22 and 24, at Downham, 
58.53 at Pendle 9.7 lower. 
Difference of altitude 1852 feet (by barometer). 
Comparison of the Angles given by Ramsden’s gr eat Theodolite, 
and the Horizon Sector. 
The angles are reduced to the ground at Rumbles Moor. 
Boulsworth, elev... .. 13.29 Theod. 18.29 Sector. 
Pendle Hill, b". elev. .. 9.16 9.18 
Great Whernside, elev. 25.45 26. 8 
As all the angles by the Sector include its error of 26”, it would 
appear that the Theodolite was affected by a similar defect, or 
that the observations were made during the heat of the day, when 
the variation of refraction was in force. That the elevation of 
Great Whernside was incorrectly observed will be clearly proved 
in its proper place. 
XXXVII, Pro- 
