G.

ON THE RELATIVE HUMIDITY, AND ABSOLUTE AMOUNT OF VAPOUR CONTAINED IN THE ATMOSPHERE AT DIFFERENT ELEVATIONS IN THE SIKKIM HIMALAYA.

My observations for temperature and wet-bulb being for the most part desultory, taken at different dates, and under very different conditions of exposure, etc., it is obvious that those at one station are hardly, if at all, comparative with those of another, and I have therefore selected only such as were taken at the same date and hour with others taken at the Calcutta Observatory, or as can easily be reduced; which thus afford a standard (however defective in many respects) for a comparison. I need hardly remind my reader that the vapour-charged wind of Sikkim is the southerly one, which blows over Calcutta; that in its passage northwards to Sikkim in the summer months, it traverses the heated plains at the foot of the Himalaya, and ascending that range, it discharges the greater part of its moisture (120 to 140 inches annually) over the outer Himalayan ranges, at elevations of 4000 to 8000 feet. The cooling effect of the uniform covering of forest on the Sikkim ranges is particularly favourable to this deposition, but the slope of the mountains being gradual, the ascending currents are not arrested and cooled so suddenly as in the Khasia mountains, where the discharge is consequently much greater. The heating of the atmosphere, too, over the dry plains at the foot of the outer range, increases farther its capacity for the retention of vapour, and also tends to render the rain-fall less sudden and violent than on the Khasia, where the south wind blows over the cool expanse of the Jheels. It will be seen from the following observations, that in Sikkim the relative humidity of the atmosphere remains pretty constantly very high in the summer months, and at all elevations, except in the rearward valleys; and even there a humid atmosphere prevails up to 14,000 feet, everywhere within the influence of the snowy mountains. The uniformly high temperature which prevails throughout the summer, even at elevations of 17,000 and 18,000 feet, is no doubt proximately due to the evolution of heat during the condensation of these vapours. It will be seen by the pages of my journal, that continued sunshine, and the consequent heating of the soil, is almost unknown during the summer, at any elevation on the outer or southward ranges of Dorjiling: but the sunk thermometer proves that in advancing northward into the heart of the mountains and ascending, the sun’s effect is increased, the temperature of the earth becoming in summer considerably higher than that of the air. With regard to the observations themselves, they may be depended upon as comparable with those of Calcutta, the instruments having been carefully compared, and the cases of interpolation being few. The number of observations taken at each station is recorded in a separate column; where only one is thus recorded, it is not to be regarded as a single reading, but the mean, of several taken during an hour or longer period. I have rejected all solitary observations, even when accompanied by others at Calcutta; and sundry that were, for obvious reasons, likely to mislead. Where many observations were taken at one place, I have divided them into sets, corresponding to the hours at which alone the Calcutta temperature and wet-bulb thermometer are recorded,[423] in order that meteorologists may apply them to the solution of other questions relating to the distribution of heat and moisture. The Dorjiling observations, and those in the immediate neighbourhood of that station, appeared to me sufficiently numerous to render it worth while classing them in months, and keeping them in a series by themselves. The tensions of vapour are worked from the wet-bulb readings by Apjohn’s formula and tables, corrected for the height of the barometer at the time. The observations, except where otherwise noted, are taken by myself.

[423] Sunrise; 9.50 a.m.; noon; 2.40 p.m.; 4 p.m., and sunset.

SERIES I. Observations made at or near Dorjiling.

JANUARY, 1849

DORJILING CALCUTTA
No.
of
Obs.		 Place Elev.
(feet)		 Hour Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
15
15
10
  8
  9		 The Dale,[424]
Mr. Muller’s
    …
    …
    …		 6956
…
…
…
…		 9.50 a.m.
Noon
2.40 p.m.
4 p.m.
Sunset		 42·9
45·8
48·3
48·6
46·5		 32·4
33·8
37·4
37·8
37·1		 10·5
12·0
10·9
10·8
  9·4		 ·202
·212
·241
·244
·238		 67·5
72·9
76·1
75·1
71·8		 55·3
55·7
55·1
54·8
54·9		 12·2
17·2
21·0
20·3
16·9		 ·446
·455
·444
·440
·441
57     … … Mean 46·4 35·7 10·7 ·227 72·7 55·2 17·5 ·445
    Dorjiling     Calcutta  
Humidity
Vapour in cubic foot of atmosphere		 0·700
2·63 gr.		 0·562
4·86 gr.

[424] Observations were taken by Mr. Muller.

JANUARY, 1850

DORJILING CALCUTTA
No.
of
Obs.		 Place Elev.
(feet)		 Hour Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
  3
  6
  3
  5
  5
  5
13
  4

  1		 Jillapahar,
Mr. Hodgson’s
    …
    …
    …
    …
    …
Saddle of road
   at Sinchul
Pacheem		 7430
…
…
…
…
…
…
7412

7258		 Sunrise
9.50 a.m.
Noon
2.40 p.m.
4 p.m.
Sunset
Miscel.
   Do.

   Do.		 32·8
39·5
42·4
41·9
41·1
38·7
41·9
41·1

39·8		 30·1
34·7
38·0
37·8
38·5
35·6
39·9
36·4

38·7		 2·7
4·8
4·4
4·1
2·6
3·1
2·0
4·7

1·1		 ·186
·219
·246
·244
·250
·226
·263
·233

·252		 51·5
66·9
74·1
78·3
77·4
72·4
77·9
67·7

71·6		 48·5
55·1
51·7
51·4
59·5
54·7
60·1
57·2

50·5		   3·0
11·8
22·4
26·9
17·9
17·7
17·8
10·5

21·1		 ·354
·444
·395
·391
·514
·438
·525
·476

·379
45     … … Mean 39·9 36·6 3·3 ·235 70·9 54·3 16·6 ·435

 

    Dorjiling     Calcutta  
Humidity
Vapour in cubic foot of atmosphere		 0·890
2·75 gr.		 0·580
4·86 gr.

FEBRUARY, 1850

DORJILING CALCUTTA
No.
of
Obs.		 Place Elev.
(feet)		 Hour Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
  6
18
12
12
17
19
13		 Jillapahar
    …
    …
    …
    …
    …
The Dale[425]		 7430
…
…
…
…
…
6956		 Sunrise
9.50 a.m.
Noon
2.40 p.m.
4 p.m.
Sunset
Misc.		 36·9
42·9
44·8
44·8
44·0
42·4
40·8		 34·7
38·6
41·3
37·4
35·6
35·8
35·1		 2·2
4·3
3·5
7·4
8·4
6·6
5·7		 ·219
·251
·276
·241
·226
·228
·222		 60·0
72·8
79·8
82·4
81·1
76·3
69·9		 54·2
58·8
58·7
57·9
58·1
60·7
59·8		   5·8
14·0
21·1
24·5
23·0
15·6
10·1		 ·431
·503
·501
·487
·492
·536
·518
97     … … Mean 42·4 36·9 5·4 ·238 74·6 58·3 16·3 ·495
    Dorjiling     Calcutta  
Humidity
Vapour in cubic foot of atmosphere		 0·828
2·75 gr.		 0·590
5·40 gr.

[425] Observations were taken by Mr. Muller.


MARCH, 1850

DORJILING CALCUTTA
No.
of
Obs.		 Place Elev.
(feet)		 Hour Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
10
  8
  5
  8
  6
  3		 Jillapahar
    …
    …
    …
    …
Pacheem		 7430
…
…
…
…
7258		 9.50 a.m.
Noon
2.40 p.m.
4 p.m.
Sunset
Miscel.		 44·2
45·5
46·4
45·5
43·1
44·8		 42·7
43·0
44·0
43·4
41·5
44·6		 1·5
2·5
2·4
2·1
1·6
0·2		 ·290
·293
·303
·297
·278
·310		 81·6
88·2
91·3
90·1
82·9
85·0		 64·1
57·0
53·2
52·0
63·7
74·8		 17·5
31·2
38·1
38·1
19·2
10·2		 ·602
·472
·416
·399
·590
·848
40     … … Mean 44·9 43·2 1·7 ·295 86·5 60·8 25·7 ·555
    Dorjiling     Calcutta  
Humidity
Vapour in cubic foot of atmosphere		 0·940
3·42 gr.		 0·438
5·72 gr.

APRIL

DORJILING CALCUTTA
No.
of
Obs.		 Place Elev.
(feet)		 Hour Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
  3
  3
  1
  7
  2
  4
  3		 Jillapahar, 1849
    …
    …
Dr. Campbell’s, 1850
    …
    …
    …		 7430
…
…
6932
…
…
…		 9.50 a.m.
Noon
2.40 p.m.
9.50 a.m.
Noon
4 p.m.		 57·0
59·8
60·2
61·8
65·4
57·5
56·9		 40·2
44·1
44·4
53·3
52·8
53·7
51·4		 16·8
15·7
15·8
  8·5
12·6
  3·8
  5·5		 ·266
·305
·308
·417
·411
·423
·392		 90·3
97·0
97·7
86·7
91·3
88·6
82·8		 71·3
64·5
73·4
66·3
68·8
72·1
73·0		 19·0
32·5
24·3
20·4
22·5
16·5
  9·8		 ·758
·607
·812
·644
·699
·778
·800
23     … … Mean 59·8 48·6 11·3 ·360 90·6 69·9 20·7 ·728
    Dorjiling     Calcutta  
Humidity
Vapour in cubic foot of atmosphere		 0·684
3·98 gr.		 0·523
7·65 gr.

MAY

DORJILING CALCUTTA
No.
of
Obs.		 Place Elev.
(feet)		 Hour Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
  3
45		 Smith’s Hotel, 1848
Colinton,[426] 1849		 6863
7179		 Miscel.
Miscel.		 57·2
60·4		 55·0
57·9		 2·2
1·5		 ·443
·466		 88·6
90·0		 78·4
77·2		 10·2
12·8		 ·951
·917
48   … Mean 58·8 56·5 2·4 ·455 89·3 77·8 11·5 ·934
    Dorjiling     Calcutta  
Humidity
Vapour in cubic foot of atmosphere		 0·926
5·22 gr.		 0·698
9·90 gr.

[426] Observations were taken by Mr. Muller.

JUNE

DORJILING CALCUTTA
No.
of
Obs.		 Place Elev.
(feet)		 Hour Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
40 Colinton,[427] 7179 Miscel. 60·9 57·6 3·3 ·483 85·5 78·4 7·1 ·952
    Dorjiling     Calcutta  
Humidity
Vapour in cubic foot of atmosphere		 0·895
5·39 gr.		 0·800
10·17 gr.

[427] Observations were taken by Mr. Muller.


JULY, 1848

DORJILING CALCUTTA
No.
of
Obs.		 Place Elev.
(feet)		 Hour Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
18
25
24
16
31
31
31		 Jillapahar
    …
    …
    …
The Dale,[428]
    …
    …		 7430
…
…
…
6952
…
…		 9.50 a.m.
Noon
2.40 p.m.
4 p.m.
6 a.m.
2 p.m.
6 p.m.		 63·2
65·0
64·7
63·8
60·2
66·3
63·0		 61·4
62·6
62·3
61·5
58·7
63·3
60·9		 1·8
2·4
2·4
2·3
1·5
3·0
2·1		 ·548
·570
·565
·550
·537
·621
·575		 87·0
89·0
88·1
87·2
81·3
88·0
84·8		 79·4
80·0
79·4
79·5
79·0
79·6
79·2		 7·6
9·0
8·7
7·7
2·3
8·4
5·6		 ·983
1·001  
·983
·985
·969
·989
·977
176       … … Mean 63·7 61·5 2·2 ·567 86·5 79·4 7·0 ·984
    Dorjiling     Calcutta  
Humidity
Vapour in cubic foot of atmosphere		 0·929
6·06 gr.		 0·800
10·45 gr.

[428] Observations were taken by Mr. Muller.


AUGUST, 1848

DORJILING CALCUTTA
No.
of
Obs.		 Place Elev.
(feet)		 Hour Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
23
21
17
13
31
31
31		 Jillapahar
    …
    …
    …
The Dale,[429]
    …
    …		 7430
…
…
…
6952
…
…		 9.50 a.m.
Noon
2.40 p.m.
4 p.m.
6 a.m.
2 p.m.
6 p.m.		 64·2
64·7
64·7
63·9
60·5
65·3
62·8		 62·4
63·3
62·8
62·5
59·5
63·6
61·8		 1·8
1·4
1·9
1·4
1·0
1·7
1·0		 ·567
·584
·574
·568
·551
·628
·591		 85·8
87·2
87·4
86·5
80·8
87·2
83·7		 79·1
79·2
79·3
79·5
78·8
79·2
78·7		 6·7
8·0
8·1
7·0
2·0
8·0
5·0		 ·973
·976
·979
·984
·962
·976
·959
167       … … Mean 63·7 62·3 1·5 ·580 85·5 79·1 6·4 ·973
    Dorjiling     Calcutta  
Humidity
Vapour in cubic foot of atmosphere		 0·995
6·25 gr.		 0·818
10·35 gr.

[429] Observations were taken by Mr. Muller.

SEPTEMBER, 1848

DORJILING CALCUTTA
No.
of
Obs.		 Place Elev.
(feet)		 Hour Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
28
23
23
21
30
30
30		 Jillapahar
    …
    …
    …
The Dale,[430]
    …
    …		 7430
…
…
…
6952
…
…		 9.50 a.m.
Noon
2.40 p.m.
4 p.m.
6 a.m.
2 p.m.
6 p.m.		 60·8
62·4
62·4
62·0
57·4
64·9
60·8		 59·3
60·3
59·6
59·6
56·2
60·8
59·0		 1·5
2·1
2·8
2·4
1·2
4·1
1·8		 ·511
·528
·516
·516
·495
·573
·543		 87·0
88·5
88·1
86·9
80·9
88·8
84·7		 78·4
78·1
77·4
77·1
78·3
77·4
76·6		   8·6
10·4
10·7
  9·8
  2·6
11·4
  8·1		 ·952
·943
·922
·914
·948
·923
·899
185       … … Mean 61·5 59·3 2·3 ·526 86·4 77·6 8·8 ·929
    Dorjiling     Calcutta  
Humidity
Vapour in cubic foot of atmosphere		 0·932
5·72 gr.		 0·760
9·88 gr.

[430] Observations were taken by Mr. Muller.


OCTOBER, 1848

DORJILING CALCUTTA
No.
of
Obs.		 Place Elev.
(feet)		 Hour Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
  6
  6
  6
  4
  8
  8
17
19		 Jillapahar
    …
    …
Goong.
    Ditto
The Dale,[431]
    …
    …		 7430
…
…
7436
7441
6952
…
…		 Noon
2.40 p.m.
4 p.m.
Misc.
Misc.
6 a.m.
2 p.m.
6 p.m.		 55·9
55·7
55·6
48·3
51·2
55·2
61·4
56·9		 55·3
54·9
54·9
48·3
50·2
52·7
56·3
54·2		 0·6
0·8
0·7
0
1·0
2·5
5·1
2·7		 ·446
·440
·441
·352
·376
·439
·497
·463		 84·4
86·0
85·2
81·2
80·7
76·1
87·0
82·8		 75·3
73·3
74·4
73·7
66·9
74·2
71·2
73·9		   9·1
12·7
10·8
  7·5
13·8
  1·9
15·8
  8·9		 ·863
·808
·837
·819
·657
·834
·756
·824
74     … … Mean 55·0 53·4 1·7 ·432 82·9 72·9 10·1 ·800
    Dorjiling     Calcutta  
Humidity
Vapour in cubic foot of atmosphere		 0·950
4·74 gr.		 0·658
8·55 gr.

[431] Observations were taken by Mr. Muller.

NOVEMBER AND DECEMBER, 1848

DORJILING CALCUTTA
No.
of
Obs.		 Place Elev.
(feet)		 Hour Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
  4
  8
  6
  9
19		 The Dale[432]
Nov./Dec.
    …
December
    …		 6952
…
…
…
…		 6 a.m.
2 p.m.
6 p.m.
2 p.m.
6 a.m.		 45·6
60·0
50·6
49·7
44·0		 41·4
48·3
44·7
41·7
40·5		 4·2
11·7  
5·9
8·0
3·5		 ·277
·355
·311
·280
·269		 67·9
83·3
77·3
79·3
75·8		 64·7
65·2
63·1
59·0
62·6		   3·2
18·1
14·2
20·3
13·2		 ·610
·621
·579
·505
·569
46     … … Mean 49·9 43·3 6·7 ·298 76·7 62·9 13·8 ·577
    Dorjiling     Calcutta  
Humidity
Vapour in cubic foot of atmosphere		 0·798
3·40 gr.		 0·640
6·27 gr.

[432] Observations were taken by Mr. Muller.

Comparison of Dorjiling and Calcutta.

    HUMIDITY WEIGHT OF VAPOUR IN
CUBIC FOOT OF AIR
No. of
Obs.		 Month Dorjiling Calcutta Diff.
Dorjiling		 Dorjiling Calcutta Diff.
Calcutta
102
  97
  40
  23
  48
  40
176
167
185
  74
  46		 January
February
March
April
May
June
July
August
September
October
Nov. and Dec.		 –·795  
·828
·940
·684
·926
·895
·929
+·955  
·932
·950
·798		 ·572
·590
–·438  
·523
·698
·800
·800
+·818  
·760
·658
·640		 +·224
+·238
+·502
+·161
+·228
+·095
+·129
+·136
+·172
+·292
+·158		 –2·68  
2·75
3·42
3·98
5·22
5·39
6·06
+6·25  
5·72
4·74
6·27		 –4.80  
5·40
5·72
7·65
9·90
10·17  
10·05  
+10·35    
9·88
8·55
6·27		 +2·12
+2·65
+2·30
+3·67
+4·62
+4·78
+3·99
+4·10
+4·16
+3·81
+2·87
998 Mean 0·876   0·663   +·212 4·51 8·07 +3·55

It is hence evident, from nearly 1000 comparative observations, that the atmosphere is relatively more humid at Dorjiling than at Calcutta, throughout the year. As the southerly current, to which alone is due all the moisture of Sikkim, traverses 200 miles of land, and discharges from sixty to eighty inches of rain before arriving at Dorjiling, it follows that the whole atmospheric column is relatively drier over the Himalaya than over Calcutta; that the absolute amount of vapour, in short, is less than it would otherwise be at the elevation of Dorjiling, though the relative humidity is so great. A glance at the table at the end of this section appears to confirm this; for it is there shown that, at the base of the Himalaya, at an elevation of only 250 feet higher than Calcutta, the absolute amount of vapour is less, and of relative humidity greater, than at Calcutta.

SERIES II. Observations at various Stations and Elevations in the Himalaya of East Nepal and Sikkim.

ELEVATION 735 TO 2000 FEET

EAST NEPAL AND SIKKIM CALCUTTA
No.
of
Obs.		 Locality Elev. Month Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
3
2
1
3
1
6
1
5
5
11  

10  		 Katong Ghat, Teesta river
Great Rungeet, at bridge
   Ditto
Tambur river, E. Nepal
   Ditto
Bhomsong, Teesta river
   Ditto
Little Rungeet
Pemiongchi, Great Rungeet
Punkabaree
   Ditto
Guard house (Gt. Rungeet)		   735
  818
  818
1388
1457
1596
1596
1672
1840
1850
1850
1864		 Dec.
April
May
Nov.
Nov.
Dec.
May
Jan.
Dec.
March
May
April		 60·2
82·8
77·8
60·6
64·2
58·6
68·2
51·0
54·6
70·1
73·5
73·7		 55·3
63·5
60·3
57·0
59·1
52·0
66·4
50·2
53·7
55·6
68·3
63·8		 4·9
19·3  
17·5  
3·6
5·1
6·6
1·8
0·8
0·9
14·5  
5·2
9·9		 ·447
·588
·528
·473
·507
·399
·647
·377
·424
·472
·687
·592		 73·2
95·8
91·7
73·3
77·3
71·6
82·6
58·5
73·5
79·2
83·7
92·4		 56·7
61·9
78·3
62·7
63·4
57·0
77·4
58·0
66·2
62·6
77·9
67·0		 16·5
33·9
13·4
10·6
13·9
14·6
  5·2
  0·5
  7·3
16·6
  5·8
25·4		 ·468
·557
·947
·571
·585
·474
·923
·489
·642
·570
·938
·660
48     Mean 66·3 58·8 7·5 ·512 79·4 65·8 13·6 ·652
  East Nepal
and Sikkim		 Calcutta
Humidity
Weight of vapour		 0·717
5·57 gr.		 0·663
6·88 gr.

ELEVATION 2000 TO 3000 FEET

EAST NEPAL AND SIKKIM CALCUTTA
No.
of
Obs.		 Locality Elev. Month Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
2
8
3
3
2
8
12  
8
3		 Singdong
Mywa Guola, E. Nepal
Pemmi river, E. Nepal
Tambur river, E. Nepal
Blingbong (Teesta)
Lingo (Teesta)
Serriomsa (Teesta)
Lingmo (Teesta)
    Ditto		 2116
2132
2256
2545
2684
2782
2820
2849
2952		 Dec.
Nov.
Nov.
Nov.
May
May
Dec.
May
Dec.		 60·5
66·2
55·6
57·3
72·6
75·8
64·1
68·6
56·4		 53·4
57·5
53·9
51·6
64·0
67·3
56·8
64·6
53·5		 7·1
8·7
1·7
5·7
8·6
8·5
7·3
4·0
2·9		 ·419
·481
·426
·394
·597
·666
·469
·610
·420		 72·1
75·7
62·9
75·0
81·7
90·7
70·8
87·9
69·5		 52·9
68·7
62·3
63·7
73·6
77·7
62·4
74·9
66·5		 19·2
  7·0
  0·6
11·3
  8·1
13·0
  8·4
13·0
  3·0		 ·411
·697
·566
·591
·817
·932
·567
·851
·647
49     Mean 64·1 58·1 6·1 ·498 76·3 67·0 9·3 ·675
  East Nepal
and Sikkim		 Calcutta
Humidity
Weight of vapour		 0·820
5·45 gr.		 0·740
7·13 gr.

ELEVATION 3000 TO 4000 FEET

EAST NEPAL AND SIKKIM CALCUTTA
No.
of
Obs.		 Locality Elev. Month Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
5
9
3
2
2
7
7
1
3
1
1
2
5		 Kulhait river
Ratong river
Tambur river
Chingtam
Tikbotang
Myong Valley
Iwa river
Ratong river
Tukcham
Pacheem village
Yankoong
Mikk
Sunnook		 3159
3171
3201
3404
3763
3782
3783
3790
3849
3855
3867
3912
3986		 Jan.
Jan.
Nov.
Nov.
Dec.
Oct.
Dec.
Jan.
Nov.
Jan.
Dec.
May
Dec.		 49·8
44·2
53·0
54·8
56·5
61·4
47·5
56·2
68·8
54·5
50·0
66·1
47·9		 47·0
43·0
50·0
49·0
53·4
58·4
45·6
41·1
65·4
46·3
43·6
63·9
45·5		 2·8
1·2
3·0
5·8
3·1
3·0
1·9
15·1  
3·4
8·2
6·4
2·2
2·4		 ·337
·294
·373
·360
·419
·496
·321
·275
·625
·329
·299
·595
·320		 65·8
69·9
72·9
74·9
68·0
80·7
73·3
75·8
83·7
73·6
69·1
84·3
69·4		 57·3
56·6
63·2
73·0
61·8
71·2
64·7
53·0
76·8
59·4
63·8
75·1
61·1		 8·5
13·3  
9·7
1·9
6·2
9·5
8·6
22·8  
6·9
14·2  
5·3
9·2
8·3		 ·477
·466
·582
·802
·555
·755
·611
·414
·904
·513
·593
·856
·542
48     Mean 54·7 50·2 4·5 ·388 74·0 64·4 9·6 ·621
  East Nepal
and Sikkim		 Calcutta
Humidity
Weight of vapour		 0·858
4·23 gr.		 0·732
6·60 gr.

ELEVATION 4000 TO 5000 FEET

EAST NEPAL AND SIKKIM CALCUTTA
No.
of
Obs.		 Locality Elev. Month Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
3
4
2
3
7
3
6
7
10  
5
5
2
16  
6
4
4
2
4
7
6
3
6
11  
9		 Yangyading
Gorh
Namgah
Taptiatok (Tambur)
Myong Valley
Jummanoo
Nampok
Chakoong
Singtam
Namten
Purmiokshong
Rungniok
Singtam
Cheadam
Sablakoo
Bheti
Temi
Lingtam
Khersiong
    Ditto
Tassiding
Lingcham
Dikkeeling
Tchonpong		 4111
4128
4229
4283
4345
4362
4377
4407
4426
4483
4521
4565
4575
4653
4676
4683
4771
4805
4813
4813
4840
4870
4952
4978		 Dec.
May
Oct.
Nov.
Oct.
Nov.
Dec.
May
May
Dec.
Nov.
Jan.
Oct/Nov.
Dec.
Dec.
Nov.
May
May
Jan.
Mar.
Dec.
Dec.
Dec.
Jan.
 52·0
66·4
57·2
51·3
59·1
60·4
49·6
57·8
62·4
44·7
60·5
54·7
63·8
51·4
50·1
59·0
59·8
60·4
51·0
53·6
52·0
48·5
62·0
49·4
 43·6
59·0
54·1
45·8
57·8
50·0
49·1
57·6
61·7
44·3
56·5
44·3
60·1
46·6
44·9
52·3
50·1
56·6
45·2
45·5
46·6
46·1
55·3
34·7		 8·4
7·4
3·1
5·5
1·3
10·4  
0·5
0·2
0·7
0·4
4·0
10·4  
3·7
4·8
5·2
6·7
9·7
3·8
5·8
8·1
5·4
2·4
6·7
14·7  		 ·300
·506
·429
·323
·487
·374
·362
·483
·553
·307
·466
·307
·525
·332
·314
·405
·374
·467
·316
·320
·333
·327
·447
·219		 71·1
85·5
80·8
73·3
81·7
77·4
64·1
83·9
88·6
64·8
79·2
66·5
82·5
70·2
72·9
78·3
81·2
80·0
67·0
77·1
79·7
78·5
80·8
71·0		 67·2
74·2
73·7
64·8
72·9
70·2
56·3
76·2
79·0
58·3
69·5
59·7
76·7
55·0
65·7
66·1
74·1
73·8
49·8
70·5
60·8
71·8
62·0
54·7		 3·9
11·3  
7·1
8·5
8·8
7·2
7·8
7·7
9·6
6·5
9·7
6·8
5·8
15·2  
7·2
12·2  
7·1
6·2
17·2  
6·6
18·9  
6·7
18·8  
16·3  		 ·663
·834
·819
·614
·797
·731
·462
·889
·969
·495
·715
·517
·901
·442
·632
·639
·834
·820
·370
·738
·538
·771
·559
·439
137         Mean 55·7 50·4 5·4 ·387 76·5 66·8 9·7 ·675
  East Nepal
and Sikkim		 Calcutta
Humidity
Weight of vapour		 0·837
4·33 gr.		 0·730
7·12 gr.

ELEVATION 5000 TO 6000 FEET

EAST NEPAL AND SIKKIM CALCUTTA
No.
of
Obs.		 Locality Elev. Month Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
4
4
2
7
5
3
4
6
8
8
7
6
8
5
6
3
8
6
3
4
6
16  
2
4
3
3
3
3
2
3
3
22  
21  
20  
21  
21  		 Nampok
Tengling
Choongtam, sunrise
Choongtam, 9.50 a.m.
Choongtam, noon
Choongtam, 2.45 p.m.
Choongtam, 4 p.m.
Choongtam, sunset
Choongtam, 9.50 a.m.
Choongtam, noon
Choongtam, 2.40 p.m.
Choongtam, 4 p.m.
Choongtam, sunset
Sulloobong
Lingdam
Makaroumbi
Khabang
Lingdam
Yankutamg
Namtchi
Yoksun
    Ditto
Loongtoon
Sakkiazong
Phadong, 8 a.m.
Phadong, 9.50 a.m.
Phadong, noon
Phadong, 2.40 p.m.
Phadong, 4 p.m.
Phadong, sunset
Tumloong
Tumloong, 9. 50 a.m.
Tumloong, noon
Tumloong, 2.40 p.m.
Tumloong, 4 p.m.
Tumloong, sunset		 5075
5257
5368
5368
5368
5368
5368
5368
5368
5368
5368
5368
5368
5277
5375
5485
5505
5554
5564
5608
5619
5619
5677
5625
5946
5946
5946
5946
5946
5946
5368
5976
5976
5976
5976
5976		 May
Jan.
May
May
May
May
May
May
Aug.
Aug.
Aug.
Aug.
Aug.
Nov.
Dec.
Nov.
Dec.
Dec.
Dec.
May
Jan.
Jan.
Nov.
Nov.
Nov.
Nov.
Nov.
Nov.
Nov.
Nov.
Nov.
Nov/Dec.
Nov/Dec.
Nov/Dec.
Nov/Dec.
Nov/Dec.		 65·8
44·7
54·9
71·5
71·0
66·4
63·5
61·4
76·3
78·8
72·9
69·5
66·9
57·6
44·3
52·1
55·1
45·0
43·6
67·1
42·7
43·0
45·3
54·1
51·9
55·9
60·7
57·4
55·5
53·7
64·2
54·1
57·3
57·3
54·7
51·8		 60·8
39·1
54·7
58·9
59·4
59·4
59·2
60·5
66·1
67·8
66·5
66·8
65·4
51·2
43·0
48·1
47·3
43·7
41·7
61·2
34·0
33·9
42·8
50·9
50·8
53·0
56·5
54·7
52·8
52·6
62·6
50·0
51·7
51·4
50·5
48·5		 5·0
5·6
0·2
12·6  
11·6  
7·0
4·3
0·9
10·2  
11·0  
6·4
2·7
1·5
6·4
1·3
4·0
7·8
1·3
1·9
5·9
8·7
9·1
2·5
3·2
1·1
2·9
4·2
2·7
2·7
1·1
1·6
4·1
5·6
5·9
4·2
3·3		 ·537
·257
·438
·504
·513
·513
·510
·532
·640
·677
·649
·655
·627
·390
·293
·350
·340
·301
·280
·544
·214
·213
·292
·358
·383
·413
·465
·438
·410
·408
·570
·375
·396
·391
·380
·355		 83·1
65·4
78·2
89·8
92·7
95·4
93·6
89·1
85·3
86·6
86·4
85·3
83·6
79·4
68·8
72·5
75·0
71·0
69·5
87·7
68·2
66·2
72·1
78·3
75·0
80·9
85·6
86·6
85·5
80·6
83·8
75·1
79·7
81·3
80·2
76·7		 74·7
38·1
73·9
80·0
79·9
78·7
79·0
77·1
78·9
78·8
78·8
79·3
78·5
65·8
59·9
60·5
64·7
56·5
63·1
74·9
58·1
51·9
63·8
66·1
67·5
67·9
64·8
62·2
61·9
67·4
77·5
61·9
60·1
58·0
58·6
61·2		   8·4
27·3
  4·3
  9·8
12·8
16·7
14·6
12·0
  6·4
  7·8
  7·6
  6·0
  5·1
13·6
  8·9
12·0
10·3
14·5
  6·4
12·8
10·1
14·3
  8·3
12·2
  7·5
13·0
20·8
24·4
23·6
13·2
  6·3
13·2
19·6
23·3
21·6
15·5		 ·845
·247
·826
1·000  
·999
·959
·971
·915
·967
·965
·963
·980
·956
·634
·521
·532
·611
·466
·579
·850
·492
·399
·595
·639
·670
·678
·613
·562
·557
·667
·924
·557
·524
·489
·499
·545
260         Mean 57·7 53·3 4·5 ·438 77·6 67·8 9·8 ·700
  East Nepal
and Sikkim		 Calcutta
Humidity
Weight of vapour		 0·865
4·70 gr.		 0·730
7·34 gr.

ELEVATION 6000 TO 7000 FEET

EAST NEPAL AND SIKKIM CALCUTTA
No.
of
Obs.		 Locality Elev. Month Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
5
11  
11  
4
2
4
4
3
1
10  
4
6
7
4		 Runkpo
Leebong
    Ditto
Dholeep
Iwa River
Dengha
Kulhait River
Latong
Doobdi
Pemiongchi
Keadom
Hee-hill
Dumpook
Changachelling		 6008
6021
6021
6133
6159
6368
6390
6391
6472
6584
6609
6677
6678
6828		 Nov.
Feb.
Jan.
May
Dec.
Aug.
Dec.
Oct.
Jan.
Jan.
Aug.
Jan.
Jan.
Jan.		 57·5
47·8
47·8
60·5
41·2
66·7
41·9
54·0
46·6
40·7
63·5
40·8
40·2
50·6		 54·8
43·7
43·4
59·9
40·5
64·0
41·9
53·2
36·2
35·8
60·0
34·1
31·8
31·8		 2·7
4·1
4·4
0·6
0·7
2·7
0
0·8
10·4  
4·9
3·5
6·7
8·4
18·8  		 ·440
·300
·297
·520
·269
·597
·283
·416
·231
·228
·523
·215
·198
·198		 79·5
74·9
66·9
89·4
69·6
86·1
71·3
55·5
78·7
66·3
79·7
64·0
68·5
68·3		 73·4
59·7
56·2
81·4
60·2
78·8
60·9
44·1
58·0
54·4
77·5
58·0
53·8
53·6		   6·1
15·2
10·7
  8·0
  9·4
  7·3
10·4
11·4
20·7
11·9
  2·2
  6·0
14·7
14·8		 ·810
·517
·460
·046
·527
·962
·539
·305
·490
·434
·925
·489
·426
·423
76     Mean 50·0 45·1 4·9 ·337 72·8 62·1 10·6 ·597
  East Nepal
and Sikkim		 Calcutta
Humidity
Weight of vapour		 0·845
3·60 gr.		 0·701
6·11 gr.

ELEVATION 7000 TO 8000 FEET

EAST NEPAL AND SIKKIM CALCUTTA
No.
of
Obs.		 Locality Elev. Month Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
1
2
8
1
1
4
8		 Pemiongchi
Goong
Kampo-Samdong
Hee-hill
Ratong river
Source of Balasun
Goong ridge		 7083
7216
7329
7289
7143
7436
7441		 Jan.
Nov.
May/Aug.
Jan.
Jan.
Oct.
Oct.		 46·2
49·0
59·1
51·3
36·5
48·3
51·2		 33·5
48·5
58·2
26·4
25·3
48·3
50·2		 12·7
  0·5
  0·9
24·9
11·2
0
  1·0		 ·210
·355
·493
·163
·157
·352
·376		 76·8
79·7
83·6
72·8
60·0
81·2
80·7		 51·8
69·1
77·4
56·6
52·9
73·7
66·9		 25·0
10·6
  6·2
16·2
  7·1
  7·5
13·8		 ·396
·705
·922
·466
·412
·819
·657
35 Dorjiling   Mean 48·8 41·5   7·3 ·301 76·4 64·1 12·8 ·625
  From mean of
above and Dorjiling		 Calcutta
Humidity
Weight of vapour		 0·826
3·85 gr.		 0·668
7·28 gr.

ELEVATION 8000 TO 9000 FEET

EAST NEPAL AND SIKKIM CALCUTTA
No.
of
Obs.		 Locality Elev. Month Temp. Dew
Point		 Diff. Tens. Temp. Dew
Point		 Diff. Tens.
  4
  2
  1
  2
  3
  4
  6
  9
  1
11
12
  7
  4
  7
10
12
10
10
  4
  5
  6
  8
11
11
  7
  6
  8
10
  1
  1		 Sinchul
Sinchul
Ascent of Tonglo
Tambur river
Sakkiazong
Chateng
Buckim
Buckim
Chateng
Lachoong, 7 a.m.
Lachoong, 9.50 a.m.
Lachoong, noon
Lachoong, 2.40 p.m.
Lachoong, 4 p.m.
Lachoong, sunset
Lachoong, Miscellaneous
Lamteng, 6 a.m.
Lamteng, 9.50 a.m.
Lamteng, noon
Lamteng, 2.40 p.m.
Lamteng, 4 p.m.
Lamteng, sunset
Zemu Samdong, 7 a.m.
Zemu Samdong, 9.50 a.m.
Zemu Samdong, noon
Zemu Samdong, 2.40 p.m.
Zemu Samdong, sunset
Zemu Samdong, 4 p.m.
Goong
Tendong (top)		 8607
8607
8148
8081
8353
8418
8659
8659
8752
8777
8777
8777
8777
8777
8777
8777
8884
8884
8884
8884
8884
8884
8976
8976
8976
8976
8976
8976
8999
8663		 Jan.
Apr.
May
Nov.
Nov.
Oct.
Jan.
Jan.
May
|
|
| Aug.
| and
| Oct.
|
|
| May,
| June,
| July
| and
| Aug.
|
|
| June
| and
| July
|
|
Nov.
May		 41·7
66·8
56·2
38·0
49·7
43·8
30·2
33·9
67·2
53·3
60·2
61·6
58·1
58·6
55·5
55·9
53·9
62·8
62·8
58·3
56·2
53·3
55·7
59·7
63·1
61·0
57·9
53·8
49·0
55·5		 34·3
44·6
54·4
33·9
37·4
43·2
22·8
33·1
60·7
51·1
55·3
57·1
56·4
53·8
54·3
49·6
52·0
56·2
56·2
54·4
54·7
52·5
55·3
52·8
57·1
58·6
56·1
52·6
48·5
50·0		 7·4
22·2  
1·8
4·1
12·3  
0·6
7·4
0·8
6·5
2·2
4·9
4·5
1·7
4·8
1·2
6·3
1·9
6·6
6·6
3·9
1·5
0·8
0·4
6·9
6·0
2·4
1·8
1·2
0·5
5·5		 ·216
·310
·434
·213
·241
·299
·143
·207
·536
·388
·447
·475
·464
·424
·432
·368
·400
·461
·461
·435
·438
·407
·448
·412
·473
·500
·459
·407
·355
·373		 66·3
96·9
86·8
71·7
74·0
79·2
68·6
69·8
89·7
83·0
87·1
90·1
88·0
87·5
84·5
85·9
59·5
88·3
92·0
92·2
92·3
88·1
80·4
86·3
88·0
89·6
89·3
82·7
79·7
88·6		 56·9
75·4
78·9
64·1
62·4
77·5
49·4
52·2
76·8
78·9
79·9
79·4
80·0
79·4
78·7
75·2
56·4
78·7
78·0
78·4
77·1
77·4
79·8
79·0
79·8
78·2
79·0
77·3
69·1
78·1		   9·4
21·5
  7·9
  7·6
11·6
  1·7
19·2
17·6
12·9
  4·1
  7·2
10·7
  8·0
  8·1
  5·8
10·7
  3·1
  9·6
14·0
13·8
15·2
10·7
  0·6
  7·3
  8·2
11·4
10·3
  5·4
10·6
10·5		 ·472
·866
·967
·599
·566
·926
·366
·403
·904
·967
·999
·983
1·007  
·981
·959
·858
·464
·959
·939
·950
·914
·922
·997
·969
·994
·944
·970
·920
·705
·943
193       Mean 54·5 50·0   4·5 ·388 83·7 73·7   9·8 ·847
  East Nepal
and Sikkim		 Calcutta
Humidity
Weight of vapour		 0·858
4·23 gr.		 0·730
8·75 gr.