The few actinometer observations which I was enabled to record, were made with two of these instruments constructed by Barrow, and had the bulbs of their thermometers plunged into the fluid of the chamber. They were taken with the greatest care, in conformity with all the rules laid down in the "Admiralty Guide," and may, I think, be depended upon. In the Sikkim Himalaya, a cloudless day, and one admitting of more than a few hours' consecutive observations, never occurs—a day fit for any observation at all is very, rare indeed. I may mention here that a small stock of ammonia-sulphate of copper in crystals should be supplied with this instrument, also a wire and brush for cleaning, and a bottle with liquid ammonia: all of which might be packed in the box.

Active 6.568. Time always mean.

Jillapahar, Dorjiling, Elev. 7430 feet, Lat. 27 degrees 3 minutes N., Long. 88 degrees 13 minutes E.

A.— APRIL 19th, 1850. Watch slow 1 minute 15 seconds mean time.

Tem. Act.
Hour Act. Act. Reduced Barom. Air
—————————————————————————————————
a.m. 8.0 to 8.13 11.1 65.5 0.9900 22.960 53.5
8.15 to 8.28 15.0 69.5 12.2645
9.0 to 9.13 17.7 71.5 14.5140 22.948 56.0
10.0 to 10.13 19.1 72.5 15.4710 22.947 57.0
11.0 to 11.13 19.0 75.0 14.9150 22.946 58.5
p.m. 0.0 to 0.13 18.8 75.0 12.7600 22.944 60.3
1.0 to 1.13 17.2 73.3 13.8976 22.939 59.4
2.0 to 2.13 17.4 74.0 13.8330 22.914 60.3
—————————————————————————————————
Black
Hour D.P. Diff. Sat. Bulb
—————————————————————————————————
a.m. 8.0 to 8.13 33.8 19.7 .505 88.0 Day unexceptional,
8.15 to 8.28 111.5 wind S.W., after
9.0 to 9.13 37.2 18.8 .153 110.0 10 a.m. squally.
10.0 to 10.13 39.7 17.3 .550 121.0
11.0 to 11.13 38.2 20.3 .500 125.0
p.m. 0.0 to 0.13 44.8 15.5 .592 120.0
1.0 to 1.13 40.7 18.7 .546 122.0 Dense haze over
2.0 to 2.13 44.1 16.2 .577 108.0 snowy Mts.
—————————————————————————————————

B.—APRIL 20th Tem. Act. Hour Act. Act. Reduced Barom. Air ————————————————————————————————— a.m. 8.0 to 8.13 11.8 64.0 10.9150 22.969 43.4 9.0 to 9.13 17.8 73.3 14.2750 22.974 36.2 10.0 to 10.13 18.8 65.0 14.7580 22.985 57.0 ————————————————————————————————— Black Hour D.P. Diff. Sat. Bulb ————————————————————————————————— a.m. 8.0 to 8.13 43.4 10.8 .691 74.0 Dense haze, 9.0 to 9.13 44.1 12.1 .662 92.0 S.E. wind, 10.0 to 10.13 42.5 14.5 .609 92.0 cloudless sky. —————————————————————————————————

Superintendent's House, Dorjiling. Elev. 6932 feet. C.—APRIL 21st. Watch slow 1 minute mean time. Tem. Act. Hour Act. Act. Reduced Barom. Air ————————————————————————————————— a.m. 8.35 to 8.48 17.3 65.0 15.7084 56.4 9.07 to 9.20 20.9 72.7 16.8872 23.447 63.8 10.0 to 10.13 23.9 77.3 18.3791 60.8 11.0 to 11.13 24.4 81.0 17.8864 ————————————————————————————————— Black Hour D.P. Diff. Sat. Bulb ————————————————————————————————— a.m. 8.35 to 8.48 47.6 8.8 .741 97.0 Day very fine, 9.07 to 9.20 49.9 13.9 .628 100.0 snowy Mts. in 10.0 to 10.13 49.2 11.6 .677 109.0 dull red haze, 11.0 to 11.13 107.5 wind S.E. faint. —————————————————————————————————

Rampore Bauleah (Ganges). Elev. 130 feet. Lat. 22 degrees 24 minutes N., Long. 88 degrees 40 minutes E.

MAY 17th, 1850.
Watch slow 15 seconds mean time.
Tem. Act.
Hour Act. Act. Reduced Barom. Air
—————————————————————————————————
a.m. 7.51 to 8.13 13.0 88.0 8.8790 29.698 87.5
9.03 to 9.16 19.5 96.0 12.5190 92.0
9.20 to 9.33 21.2 107.0 12.7836 29.615 92.3
11.15 to 11.28 21.1 105.0 12.8499 98.5
11.32 to 11.45 16.5 108.7 9.8770 29.620 98.3
p.m. 1.20 to 1.33 21.6 108.5 12.9348 104.5
1.40 to 1.53 21.4 113.7 12.4976 105.8
—————————————————————————————————
Black
Hour D.P. Diff. Sat. Bulb
—————————————————————————————————
a.m. 7.51 to 8.13 80.1 7.4 .793 91.0 S.E. wind, very
9.03 to 9.16 81.2 10.8 .715 83.8 hazy to west, sky
9.20 to 9.33 80.2 12.1 .687 132.0 pale blue.
11.15 to 11.28 74.8 23.7 .478 98.5 Wind west, rising.
11.32 to 11.45 74.3 24.0 .475 142.0
p.m. 1.20 to 1.33 76.7 27.8 .425 144.0
1.40 to 1.53 72.2 33.6 .355 134.0
—————————————————————————————————

Churra, Khasia Mountains. Elev. 4225 feet, Lat. 25 degrees 15 minutes N., Long. 91 degrees 47 minutes E. A—NOVEMBER 4th, 1850. Watch slow 7 minutes mean time. Tem. Act. Hour Act. Act. Reduced Barom. Air ————————————————————————————————— a.m. 6.20 to 6.30 5.0 63.7 4.6400 25.781 57.8 6.32 to 6.42 7.4 65.4 6.6896 59.0 7.55 to 8.05 20.0 77.5 15.2400 63.5 8.08 to 8.18 21.0 82.0 15.2040 64.4 8.20 to 8.30 24.2 85.8 10.8432 64.8 ————————————————————————————————— Black Hour D.P. Diff. Sat. Bulb ————————————————————————————————— a.m. 6.20 to 6.30 53.1 4.7 .850 75.0 Sky faint blue, 6.32 to 6.42 54.8 4.2 .870 83.0 cloudless, 7.55 to 8.05 56.9 6.6 .806 108.0 wind S.W., 8.08 to 8.18 57.3 7.1 .790 106.5 clouding. 8.20 to 8.30 59.5 5.3 .837 113.5 —————————————————————————————————