My observations for temperature and wet-_Himalayan Journals — Complete Or, Notes of a Naturalist in Bengal, the Sikkim and Nepal Himalayas, the Khasia Mountains, etc.

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.

Obs. Place Elev.

(feet) Hour Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 15

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.

Obs. Place Elev.

(feet) Hour Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 3

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.

Obs. Place Elev.

(feet) Hour Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 6

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

44·0

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.

Obs. Place Elev.

(feet) Hour Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 10

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

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.

Obs. Place Elev.

(feet) Hour Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 3

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.

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.

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.

Obs. Place Elev.

(feet) Hour Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 18

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

2·3

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.

Obs. Place Elev.

(feet) Hour Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 23

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

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.

Obs. Place Elev.

(feet) Hour Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 28

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

62·0

57·4

64·9

60·8 59·3

60·3

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

·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.

Obs. Place Elev.

(feet) Hour Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 6

19 Jillapahar

…

Goong.

Ditto

The Dale,[431]

…

… 7430

…

7436

7441

6952

…

… Noon

2.40 p.m.

4 p.m.

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

48·3

50·2

52·7

56·3

54·2 0·6

0·8

0·7

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.

Obs. Place Elev.

(feet) Hour Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 4

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

176

167

185

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

+·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.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 3

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

1388

1457

1596

1672

1840

1850

1864 Dec.

April

May

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.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 2

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.

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.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 5

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.

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.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 3

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

4840

4870

4952

4978 Dec.

May

Oct.

Nov.

Oct.

Nov.

Dec.

May

Dec.

Nov.

Jan.

Oct/Nov.

Dec.

Nov.

May

Jan.

Mar.

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.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 4

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

5277

5375

5485

5505

5554

5564

5608

5619

5677

5625

5946

5368

5976

5976 May

Jan.

May

Aug.

Nov.

Dec.

Nov.

Dec.

May

Jan.

Nov.

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

54·7

51·8 60·8

39·1

54·7

58·9

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

1·1

1·6

4·1

5·6

5·9

4·2

3·3 ·537

·257

·438

·504

·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

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.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 5

4 Runkpo

Leebong

Ditto

Dholeep

Iwa River

Dengha

Kulhait River

Latong

Doobdi

Pemiongchi

Keadom

Hee-hill

Dumpook

Changachelling 6008

6021

6133

6159

6368

6390

6391

6472

6584

6609

6677

6678

6828 Nov.

Feb.

Jan.

May

Dec.

Aug.

Dec.

Oct.

Jan.

Aug.

Jan.

Jan. 57·5

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

0·8

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.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 1

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.

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

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.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 4

1 Sinchul

Sinchul

Ascent of Tonglo

Tambur river

Sakkiazong

Chateng

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

8752

8777

8884

8976

8999

8663 Jan.

Apr.

May

Nov.

Oct.

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

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

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

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

·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.

ELEVATION 9000 TO 10,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 4

1 Yangma Guola

Nanki

Singalelah

Sakkiazong

Zemu river 9279

9320

9295

9322

9828 Nov.

Nov.

Dec.

Nov.

June 37·8

42·3

36·2

53·5

60·0 33·1

38·3

35·7

33·3

47·6 4·7

4·0

0·5

20·2

12·4 ·207

·249

·227

·209

·343 72·7

52·2

70·9

80·0

93·3 61·4

48·3

62·1

57·3

81·9 11·3

3·9

8·8

22·7

11·4 ·549

·352

·560

·478

1·062 18 Mean 46·0 37·6

8·4 ·247 73·8 62·2 11·6 ·600

East Nepal

and Sikkim Calcutta Humidity

Weight of vapour 0·747

2·80 gr. 0·724

6·28 gr.

ELEVATION 10,000 TO 11,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 13

4 Tonglo

Nanki

Yalloong river

Tonglo top

Yeunga

Zemu river

Wallanchoon

Laghep

Thlonok river, 7 a.m.

Thlonok river, 9.50 a.m.

Thlonok river, noon

Thlonok river, 2.40 p.m.

Thlonok river, 4 p.m.

Thlonok river, sunset

Yangma Valley 10,008

10,024

10,058

10,079

10,196

10,247

10,384

10,423

10,486

10,999 May

Nov.

Dec.

May

Oct.

June

Nov.

June

Dec. 51·5

42·8

37·7

49·9

45·9

45·4

37·9

46·0

37·6

48·5

57·6

56·1

54·8

53·4

49·8

31·6 50·2

35·5

29·6

47·9

44·7

44·2

30·2

42·4

37·0

47·2

51·4

50·6

48·9

24·3 1·3

7·3

8·1

2·0

1·2

7·7

3·6

0·6

1·3

6·2

5·5

4·2

2·8

0·9

7·3 ·376

·225

·183

·348

·311

·306

·187

·287

·238

·339

·392

·382

·381

·359

·149 88·8

79·5

77·7

89·4

79·5

84·6

76·5

80·9

75·3

79·0

87·4

90·0

88·5

88·7

85·5

74·4 80·8

65·8

62·1

80·5

77·1

75·1

61·9

68·0

69·4

75·1

78·8

79·3

79·7

78·7

78·0

61·9 8·0

13·7

15·6

8·9

2·4

9·5

14·6

12·9

5·9

3·9

8·6

10·7

8·8

10·0

7·5

12·3 1·030

·633

·560

1·018

·915

·856

·558

·681

·712

·856

·965

·979

·991

·962

·938

·558 123

Mean 46·7 42·8 3·8 ·303 82·8 73·3

9·5 ·826

East Nepal

and Sikkim Calcutta Humidity

Weight of vapour 0·878

3·35 gr. 0·740

8·70 gr.

ELEVATION 11,000 TO 12,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 3

7 Barfonchen

Punying

Kambachen village

Tallum, 7 a.m.

Tallum, 9.50 a.m.

Tallum, noon

Tallum, 2.40 p.m.

Tallum, 4 p.m.

Tallum, sunset

Kambachen Valley

Yeumtong, 7 a.m.

Yeumtong, 9.50 a.m.

Yeumtong, noon

Yeumtong 2.40 p.m.

Yeumtong, 4 p.m.

Yeumtong, sunset

Yeumtong, Miscellaneous 11,233

11,299

11,378

11,482

11,484

11,887

11,887 Nov.

Aug.

Dec.

July

Dec.

| Aug.,

| Sep.,

| and

| Oct.

| |

Oct. 36·8

50·2

43·3

50·4

58·1

57·9

55·7

54·3

48·8

30·4

44·4

53·6

54·5

48·8

48·4

42·0

43·5 31·9

49·5

32·5

47·8

50·5

50·8

50·2

50·1

47·3

26·0

43·8

48·9

48·3

47·4

47·1

35·9

37·1 4·9

0·7

10·8

2·6

7·6

7·1

5·5

4·2

1·5

4·4

0·6

4·7

6·2

1·4

1·3

6·1

6·4 ·198

·367

·203

·347

·380

·384

·377

·375

·340

·161

·302

·360

·353

·342

·338

·229

·239 76·3

84·5

80·0

85·0

88·1

89·7

89·3

90·3

86·6

69·9

83·0

87·5

89·7

87·2

85·2

60·6

83·7 69·6

78·8

61·2

80·3

79·7

81·3

80·6

79·4

80·0

59·5

78·9

78·7

77·2

77·8

58·5

69·7 6·7

5·7

18·8

4·7

8·4

8·7

10·9

6·6

10·4

4·1

8·8

12·5

10·0

7·4

2·1

14·0 ·719

·963

·544

1·010

·993

1·043

1·020

·981

1·001

·515

·967

·959

·917

·915

·934

·497

·720 104 Mean 48·3 43·8

4·5 ·311 83·3 74·6 8·7 ·865

East Nepal

and Sikkim Calcutta Humidity

Weight of vapour 0·860

3·46 gr. 0·760

9·00 gr.

ELEVATION 12,000 TO 13,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 9

6 Zemu river, 7 a.m.

Zemu river, 9.50 a.m.

Zemu river, noon

Zemu river, 2.40 p.m.

Zemu river, 4 p.m.

Zemu river, sunset

Tangma Valley

Zemu river

Chumanako

Tungu, 7 a.m.

Tungu, 9.50 a.m.

Tungu, noon

Tungu, 2.40 p.m.

Tungu, sunset

Tungu, sunrise

Tungu, 9.50 a.m.

Tungu, noon

Tungu, 2.40 p.m.

Tungu, 4 p.m.

Tungu, sunset

Tungu, Miscellaneous

Tuquoroma 12,070

12,070

12,129

12,422

12,590

12,751

12,994 |

| June

| and

| July

| |

| ||

Nov.

June

Nov.

July

Oct.

July

Nov. 46·6

51·1

51·2

49·7

48·1

34·8

49·0

37·3

45·1

53·1

62·3

60·0

46·4

38·2

46·5

46·1

43·8

42·3

41·0

43·2

51·3

26·0 45·6

49·0

50·2

50·3

48·9

47·6

22·7

46·6

28·3

44·1

48·6

52·7

53·8

45·3

35·0

42·8

42·0

42·1

40·8

38·7

40·8

47·7

23·4 1·0

2·1

0·9

0·8

0·5

12·1

2·4

9·0

1·0

4·5

9·6

6·2

1·1

3·2

3·7

4·1

1·7

1·5

2·3

2·4

3·6

2·6 ·321

·362

·376

·377

·360

·344

·143

·332

·174

·305

·355

·409

·425

·317

·222

·292

·284

·285

·271

·253

·272

·345

·146 80·6

84·5

87·0

86·3

86·5

81·4

70·6

93·2

75·1

80·5

87·1

88·9

85·3

84·7

79·4

85·0

86·4

85·9

83·3

84·5

85·7

75·1 77·7

75·1

82·2

80·0

80·2

77·5

63·7

79·6

73·8

78·3

79·4

77·8

79·5

79·1

77·8

78·6

78·2

78·8

78·5

78·2

78·4

79·0

60·8 2·9

9·4

4·8

6·3

3·9

6·9

13·6

1·3

2·2

7·7

11·1

5·8

5·6

1·6

6·4

6·8

7·6

7·4

5·1

6·1

6·7

14·3 ·931

·972

1·074

1·000

1·006

·926

·592

·989

·822

·949

·982

·935

·985

·974

·932

·957

·944

·963

·956

·947

·950

·971

·537 140

Mean 46·3 42·9 3·4 ·303 83·6 77·1 6·5 ·926

East Nepal

and Sikkim Calcutta Humidity

Weight of vapour 0·890

3·37 gr. 0·815

9·75 gr.

ELEVATION 13,000 TO 14,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 7

3 Mon Lepcha

Mon Lepcha

Tunkra valley

Jongri

Zemu river

Choonjerma

Yangma village

Wallanchoon road

Kambachen, below pass 13,090

13,073

13,111

13,194

13,281

13,288

13,502

13,505

13,600 Jan.

Jan.

Aug.

Jan.

June

Dec.

Nov./Dec.

Nov.

Dec. 27·1

25·6

45·0

22·7

46·7

39·0

33·8

28·0

40·0 18·5

16·4

43·5

10·5

46·7

11·1

18·6

9·5

18·6 8·6

9·2

1·5

12·2

27·9

15·2

18·5

21·4 ·122

·113

·298

·091

·334

·093

·123

·088

·123 70·0

71·7

81·2

70·6

92·9

69·8

78·9

66·4

72·9 50·8

49·4

78·7

53·2

86·6

61·8

62·1

61·8

62·2 19·2

21·8

2·5

17·4

6·2

8·0

16·8

4·6

10·7 ·527

·373

·962

·417

1·230

·555

·561

·555

·563 53

Mean 34·2 21·5 12·6 ·154 74·9 63·0 11·9 ·

636

East Nepal

and Sikkim Calcutta Humidity

Weight of vapour 0·634

1·61 gr. 0·678

6·28 gr.

ELEVATION 15,000 TO 16,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 1

1 Yangma valley

Choonjerma pass

Lachee-pia

Momay, 7 a.m.

Momay, 9.50 a.m.

Momay, noon

Momay, 2.40 p.m.

Momay, 4 p.m.

Momay, sunset

Momay, Miscellaneous

Sittong

Palung

Kambachen pass

Yeumtong 15,186

15,259

15,262

15,372

15,676

15,770

15,985 Dec.

Dec.

Aug.

Sept.

Oct.

Dec.

Sept. 42·2

34·3

42·0

39·4

50·9

51·7

49·7

44·4

41·5

47·6

40·9

38·6

44·6

26·5

44·6 20·7

10·5

41·6

34·7

41·7

43·6

41·9

41·3

38·6

41·4

36·5

29·8

39·8

15·9

43·7 21·5

23·8

0·4

4·7

9·2

8·1

7·8

3·1

2·9

6·2

4·4

8·8

4·8

10·6

0·9 ·133

·091

·279

·219

·280

·299

·283

·276

·252

·277

·234

·184

·262

·111

·300 80·8

77·9

85·5

80·5

87·6

89·5

90·0

88·7

84·2

87·4

83·9

84·0

86·8

78·0

88·8

62·0

60·6

79·4

78·8

79·7

78·3

77·6

78·4

78·6

69·3

77·5

78·5

58·5

80·5 18·8

17·3

6·1

1·7

8·8

9·8

11·7

11·1

5·8

8·8

14·6

6·5

8·3

19·5

8·3 ·559

·534

·982

·966

·963

·990

·949

·928

·952

·956

·710

·926

·954

·498

1·016 87 Mean 42·6 34·8

7·8 ·232 84·9 74·4 10·5 ·859

East Nepal

and Sikkim Calcutta Humidity

Weight of vapour 0·763

2·55 gr. 0·719

8·95 gr.

ELEVATION 16,000 TO 17,000 FEET

EAST NEPAL AND SIKKIM CALCUTTA No.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 1

1 Kanglachem pass

Tunkra pass

Wallanchoon pass

Yeumtso

Cholamoo lake

Donkia mountain 16,038

16,083

16,756

16,808

16,900

16,978 Dec.

Aug.

Nov.

Oct.

Sept. 32·8

39·8

18·0

32·4

31·4

40·2 16·3

38·7

–6·0

25·1

20·2

25·9 16·5

1·1

24·0

7·3

11·2

14·3 ·110

·252

·046

·156

·130

·160 80·7

86·0

79·9

85·0

79·8

87·6 61·1

78·7

57·6

75·7

68·4

78·8 19·6

7·3

22·3

9·3

11·4

8·8 ·543

·959

·483

·872

·690

·963 17

Mean 32·4 20·0 12·4 ·142 83·2 70·1 13·3 ·

752

East Nepal

and Sikkim Calcutta Humidity

Weight of vapour 0·640

1·53 gr. 0·658

7·80 gr.

ELEVATION 17,000 TO 18,500 FEET

EAST NEPAL AND SIKKIM CALCUTTA No.

Obs. Locality Elev. Month Temp. Dew

Point Diff. Tens. Temp. Dew

Point Diff. Tens. 1

2 Kinchinjhow

Sebolah pass

Donkia mountain

Bhomtso

Donkia pass

Donkia pass 17,624

17,585

18,307

18,450

18,466

18,466 Sept.

Sept.

Oct.

Sept.

Oct. 47·5

46·5

38·8

54·0

41·8

40·1 30·9

34·6

35·3

4·4

30·3

25·0 16·6

11·9

3·5

49·6

11·5

15·1 ·191

·218

·224

·072

·188

·155 85·7

88·8

90·7

91·1

84·1

86·5 79·7

80·0

79·3

61·1

78·4

65·5 6·0

8·8

11·4

20·0

5·7

21·0 ·991

1·002

·981

·543

·950

·627 10

Mean 44·8 26·8 18·0 ·175 87·8 74·0 12·2 ·

849

East Nepal

and Sikkim Calcutta Humidity

Weight of vapour 0·532

1·90 gr. 0·648

8·78 gr.

SUMMARY

HUMIDITY WEIGHT OF VAPOUR No. of

Obs. Elevations in

Feet Stations Sikkim Calcutta Diff.

Sikkim Sikkim Calcutta Diff.

Sikkim 48

137

260

1023

193

123

104

140

10 735 to 2000

2000 to 3000

3000 to 4000

4000 to 5000

5000 to 6000

6000 to 7000

7000 to 8000

8000 to 9000

9000 to 10,000

10,000 to 11,000

11,000 to 12,000

12,000 to 13,000

13,000 to 14,000

15,000 to 16,000

16,000 to 17,000

17,000 to 18,000 9

5 ·717

·820

·858

·837

·865

·845

·826

·858

·747

·878

·860

·890

·634

·763

·640

·532 ·663

·740

·732

·730

·701

·668

·730

·724

·740

·760

·815

·678

·719

·658

·648 +·054

·080

·116

·107

·135

·144

·158

·128

·023

·138

·100

·075

–·044

+·044

·018

–·116 5·57

5·45

4·23

4·33

4·70

3·60

3·85

4·23

2·80

3·35

3·46

3·37

1·61

2·55

1·53

1·90 6·88

7·13

6·60

7·12

7·34

6·71

7·28

8·75

6·28

8·70

9·00

9·75

6·28

8·95

7·80

8·78 –1·31

1·68

2·37

2·79

2·64

3·11

3·43

4·52

3·48

4·35

5·54

6·38

4·67

6·40

6·27

6·88 2386 154

Considering how desultory the observations in Sikkim are, and how much

affected by local circumstances, the above results must be considered

highly satisfactory: they prove that the relative humidity of the

atmospheric column remains pretty constant throughout all elevations,

except when these are in a Tibetan climate; and when above 18,000 feet,

elevations which I attained in fine weather only. Up to 12,000 feet

this constant humidity is very marked; the observations made at greater

elevations were almost invariably to the north, or leeward of the great

snowy peaks, and consequently in a drier climate; and there it will be

seen that these proportions are occasionally inverted; and in Tibet

itself a degree of relative dryness is encountered, such as is never

equalled on the plains of Eastern Bengal or the Gangetic delta. Whether

an isolated peak rising near Calcutta, to the elevation of 19,000 feet,

would present similar results to the above, is not proven by these

observations, but as the relative humidity is the same at all

elevations on the outermost ranges of Sikkim, which attain 10,000 feet,

and as these rise from the plains like steep islands out of the ocean,

it may be presumed that the effects of elevation would be the same in

both cases.

The first effect of this humid wind is to clothe Sikkim with forests,

that make it moister still; and however difficult it is to separate

cause from effect in such cases as those of the reciprocal action of

humidity on vegetation, and vegetation on humidity, it is necessary for

the observer to consider the one as the effect of the other. There is

no doubt that but for the humidity of the region, the Sikkim Himalaya

would not present the uniform clothing of forest that it does; and, on

the other hand, that but for this vegetation, the relative humidity

would not be so great.[433]

[433] Balloon ascents and observations on small mountainous islands,

therefore, offer the best means of solving such questions: of these,

the results of ballooning, under Mr. Welsh’s intrepid and skilful

pioneering (see Phil. Trans. for 1853), have proved most satisfactory;

though, from the time for observation being short, and from the

interference of belts of vapour, some anomalies have not been

eliminated. Islands again are still more exposed to local influences,

which may be easily eliminated in a long series of observations. I

think that were two islands, as different in their physical characters

as St. Helena and Ascension, selected for comparative observations, at

various elevations, the laws that regulate the distribution of

humidity in the upper regions might be deduced without difficulty.

They are advantageous sites, from differing remarkably in their

humidity. Owing partly to the indestructible nature of its component

rock (a glassy basalt), the lower parts of Ascension have never

yielded to the corroding effects of the moist sea air which surrounds

it; which has decomposed the upper part into a deep bed of clay. Hence

Ascension does not support a native tree, or even shrub, two feet

high. St. Helena, on the other hand, which can hardly be considered

more favourably situated for humidity, was clothed with a redundant

vegetation when discovered, and trees and tree-ferns (types of

humidity) still spread over its loftiest summits. Here the humidity,

vegetation, and mineral and mechanical composition reciprocate their

influences.

The great amount of relative humidity registered at 6000 to 8000 feet,

arises from most of the observations having been made on the outer

range, where the atmosphere is surcharged. The majority of those at

10,000 to 12,000 feet, which also give a disproportionate amount of

humidity, were registered at the Zemu and Thlonok rivers, where the

narrowness of the valleys, the proximity of great snowy peaks, and the

rank luxuriance of the vegetation, all favour a humid atmosphere.

I would have added the relative rain-fall to the above, but this is so

very local a phenomenon, and my observations were so repeatedly

deranged by having to camp in forests, and by local obstacles of all

kinds, that I have suppressed them; their general results I have given

in Appendix F.

I here add a few observations, taken on the plains at the foot of the

Sikkim Himalaya during the spring months.

_Comparison between Temperature and Humidity of the Sikkim Terai and

Calcutta, in March and April, 1849._

No.

Obs. Locality Elev.

above

sea.

Feet TEMPERATURE DEW POINT TENSION SAT.

C. T. C. T. C. T. C. T. 4

8 Rummai

Belakoba

Rangamally

Bhojepore

Thakyagunj

Bhatgong

Sahibgunj

Titalya 293

368

275

404

284

225

231

362 82·2

92·8

84·2

90·1

84·9

87·4

80·2

85·5 70·6

85·5

75·0

81·2

77·1

74·9

68·0

80·0 61·7

62·6

68·7

54·1

61·3

64·7

66·2

55·4 60·5

63·0

62·5

44·3

60·8

54·6

53·1

56·1 ·553

·570

·695

·429

·547

·611

·642

·448 ·532

·578

·568

·308

·537

·436

·414

·459 ·517

·382

·605

·313

·466

·480

·635

·376 ·717

·485

·665

·295

·588

·512

·409

·459 31

Means 305 85·9 79·0 61·8 56·9 ·562 ·479 ·

472 ·516 May, 1850

Kishengunj 131 89·7 K 78·6 76·7 K 71·4

·904 K ·759 ·665 K ·793

Vapour in a cubic foot Kishengunj

Calcutta 8·20

9·52 Terai

Calcutta 5·08

5·90

Mean difference of temperature between Terai and Calcutta,

from 31 observations in March, as above, excluding mimima,

Terai

Mean difference from 26 observations in March, including mimima, Terai

Mean difference of temperature at Siligoree on May 1, 1850

Mean difference of temperature at Kishengunj on May 1, 1850 6·9

9·7

10·9

11·1

From the above, it appears that during the spring months, and before

the rains commence, the belt of sandy and grassy land along the

Himalaya, though only 3·5° north of Calcutta, is at least 6° or 7°

colder, and always more humid relatively, though there is absolutely

less moisture suspended in the air. After the rains commence; I believe

that this is in a great measure inverted, the plains becoming

excessively heated, and the temperature being higher than at Calcutta.

This indeed follows from the well known fact that the summer heat

increases greatly in advancing north-west from the Bay of Bengal to the

trans-Sutledge regions; it is admirably expressed in the maps of Dove’s

great work “On the Distribution of Heat on the Surface of the Globe.”

ON THE TEMPERATURE OF THE SOIL AT VARIOUS ELEVATIONS.

These observations were taken by burying a brass tube two feet six

inches to three feet deep, in exposed soil, and sinking in it, by a

string or tied to a slip of wood, a thermometer whose bulb was well

padded with wool: this, after a few hours’ rest, indicates the

temperature of the soil. Such a tube and thermometer I usually caused

to be sunk wherever I halted, if even for one night, except during the

height of the rains, which are so heavy that they communicate to the

earth a temperature considerably above that of the air.

The results proved that the temperature of the soil at Dorjiling varies

with that of the month, from 46° to 62·2°, but is hardly affected by

the diurnal variation, except in extreme cases. In summer, throughout

the rains, May to October, the temperature is that of the month, which

is imparted by the rain to the depth of eleven feet during heavy

continued falls (of six to twelve inches a day), on which occasions I

have seen the buried thermometer indicating a temperature above the

mean of the month. Again, in the winter months, December and January,

it stands 5° above the monthly mean; in November and February 4° to 5°;

in March a few degrees below the mean temperature of the month, and in

October above it; April and May being sunny, it stands above their

mean; June to September a little below the mean temperature of each

respectively.

The temperature of the soil is affected by:—1. The exposure of the

surface; 2. The nature of the soil; 3. Its permeability by rain, and

the presence of underground springs; 4. The sun’s declination; 5. The

elevation above the sea, and consequently the heating power of the

sun’s rays: and 6, The amount of cloud and sunshine. far from being

sufficient to supply data for the exact estimation of the effects of

the sun on the soil at any elevation or locality; they, however,

indicate with tolerable certainty the main features of this phenomenon,

and these are in entire conformity with more ample series obtained

elsewhere. The result, which at first sight appears the most anomalous,

is, that the mean temperature of the soil, at two or three feet depth,

is almost throughout the year in India above that of the surrounding

atmosphere. This has been also ascertained to be the case in England by

several observers, and the carefully conducted observations of Mr.

Robert Thompson at the Horticultural Society’s Gardens at Chiswick,

show that the temperature of the soil at that place is, on the mean of

six years, at the depth of one foot, 1° above that of the air, and at

two feet 1·5°. During the winter months the soil is considerably (l° to

3°) warmer than the air, and during summer the soil is a fraction of a

degree cooler than the air.

In India, the sun’s declination being greater, these effects are much

exaggerated, the soil on the plains being in winter sometimes 9° hotter

than the air; and at considerable elevations in the Himalaya very much

more than that; in summer also, the temperature of the soil seldom

falls below that of the air, except where copious rain-falls

communicate a low temperature, or where forests interfere with the

sun’s rays.

At considerable elevations these effects are so greatly increased, that

it is extremely probable that at certain localities the mean

temperature of the soil may be even 10° warmer than that of the air;

thus, at Jongri, elevation 13,194 feet, the soil in January was 34·5°,

or 19·2° above the mean temperature of the month, immediately before

the ground became covered with snow for the remainder of the winter;

during the three succeeding months, therefore, the temperature of the

soil probably does not fall below that of the snow, whilst the mean

temperature of the air in January may be estimated at about 20°,

February 22°, March 30°, and April 35°. If, again, we assume the

temperature of the soil of Jongri to be that of other Sikkim localities

between 10,000 and 14,000 feet, we may assume the soil to be warmer by

10° in July (see Tungu observations), by 8° or 9° in September (see

Yeumtong); by l0° in October (see Tungu); and by 7° to l0° in November

(see Wallanchoon and Nanki). These temperatures, however, vary

extremely according to exposure and amount of sunshine; and I should

expect that the greatest differences would be found in the sunny

climate of Tibet, where the sun’s heat is most powerful. Were nocturnal

or terrestrial radiation as constant and powerful as solar, the effects

of the latter would be neutralised; but such is not the case at any

elevation in Sikkim.

This accumulated heat in the upper strata of soil must have a very

powerful effect upon vegetation, preventing the delicate rootlets of

shrubs from becoming frozen, and preserving vitality in the more

fleshy, roots, such as those of the large rhubarbs and small orchids,

whose spongy cellular tissues would no doubt be ruptured by severe

frosts. To the burrowing rodents, the hares, marmots, and rats, which

abound at 15,000 to 17,000 feet in Tibet, this phenomenon is even more

conspicuously important; for were the soil in winter to acquire the

mean temperature of the air, it would take very long to heat after the

melting of the snow, and indeed the latter phenomenon would be greatly

retarded. The rapid development of vegetation after the disappearance

of the snow, is no doubt also proximately due to the heat of the soil,

quite as much as to the increased strength of the sun’s direct rays in

lofty regions.

I have given in the column following that containing the temperature of

the sunk thermometer, first the extreme temperatures of the air

recorded during the time the instrument was sunk; and in the next

following, the mean temperature of the air during the same period, so

far as I could ascertain it from my own observations.

SERIES I. _Soane Valley_

Locality Date Eleva-

tion

(feet) Depth

(ft. in.) Temperature

of sunk

Thermometer Extreme

Temperature

of Air

observed Approx.

Mean

Temp.

of Air

deduced Diff.

between

Air and

sunk

Therm. Muddunpore

Nourunga

Baroon

Tilotho

Akbarpore Feb. 11 to 12

Feb. 12 to 13

Feb. 13 to 14

Feb. 15 to 16

Feb. 17 to 19 440

340

345

395

400 3 4

3 8

2 4

4 6

(2 ther.)

4 6

5 6 71·5

71·7

68·5

76·5

76·0 62·0 to 77·5

57·0 to 71·0

53·5 to 76·0

58·5 to 80·0

56·9 to 79·5 67·0

67·3

67·6

67·8

68·0 +4·5

3·4

1·9

8·7

8·0

SERIES II. _Himalaya of East Nepal and Sikkim_

Locality Date Eleva-

tion

(feet) Depth

(ft. in.) Temperature

of sunk

Thermometer Extreme

Temperature

of Air

observed Approx.

Mean

Temp.

of Air

deduced Diff.

between

Air and

sunk

Therm. Base of Tonglo

Simsibong

Tonglo saddle

Tonglo summit

Simonbong

Nanki

Sakkiazong

Mywa guola

Banks of Tambur

higher up river

Wallanchoon

Yangma village

Yangma river

Bhomsong

Tchonpong

Jongri

Buckeem

Choongtam

Junction of

Thlonok and Zemu

Tungu

Lamteng

Choongtam

Lachoong

Yeumtong

Momay

Yeumtso

Lachoong

Great Rungeet

Leebong

Kursiong

Leebong

Punkabaree

Jillapahar

(Mr. Hodgson’s)

Superintendent’s house May 19

May 20

May 21 to 22

May 23

May 24

Nov. 4 to 5

Nov. 9 to 10

Nov. 17 to 18

Nov. 18 to 19

Nov. 19 to 20

Nov. 23 to 25

Nov. 30 to Dec. 3

Dec. 2 to 3

Dec. 24 to 25

Jan. 4

Jan. 10 to 11

Jan.12

May 19 to 25

June 13 to 16

July 26 to 30

Oct. 10 to 15

Aug. 1 to 3

Aug. 13 to 15

Aug. 17 to 19

Sept. 2 to 8

Sept. 10 to 14

Oct. 16 to 18

Oct. 24 to 25

Feb. 11 to 13

Feb. 14 to 15

Apr. 16

Apr. 22

May 1

| Aug. 15 to 16

| Aug. 20 to 22

| Sept. 9

| Oct. 6

| Oct. 20

| Feb. 18 to 28

| Mar. 1 to 13

| Apr. 18 to 20

| Apr. 30

Apr. 21 to 30 3,000

7,000

10,008

10,079

5,000

9,300

8,353

2,132

2,545

3,201

10,386

13,502

10,999

1,596

4,978

13,194

8,665

5,268

10,846

12,751

8,884

5,268

8,712

11,919

15,362

16,808

8,712

818

6,000

4,813

6,000

1,850

7,430

6,932 2 0

2 0

2 6

3 0

2 0

2 7

2 5

2 7

5 0

7 7

5 0

7 7

5 0

7 7

2 7

2 7 78

61·7

50·7[434]

49·7

69·7

51·5

53·2

73·0

71·0

64·5

43·5 to 45·0

37·3 to 38·0

41·4 to 42·0

64·5 to 65·0

55·0

34·5

43·2

62·5 to 62·7

51·2

59·0 to 56·5

50·8 to 52·5

62·2 to 62·5

72·1

66·3 to 66·0

55·5 to 56·1

52·5 to 51·5

43·5 to 43·0

60·2

65·0

50·8 to 52·0

64·5

61·8 to 62·0

80·0

62·0 to 62·8

61·5 to 62·3

61·6 to 61·7

60·7

60·2

60·5

60·0

58·5

46·0 to 46·7

46·3 to 48·3

55·3 to 56·0

57·4

58·8 to 60·2 67·5 to 67·0

59·0 to 59·5

47·5 to 57·5

47·5 to 53·2

51·2 to 55·5

33·0 to 50·5

37·8 to 55·0

41·0 to 85·0

48·0 to 65·0

44·3 to 60·0

25·0 to 49·7

20·0 to 46·0

23·0 to 40·0

42·8 to 71·3

33·0 to 54·8

3·7 to 34·0

40·0 to 29·8

48·0 to 78·3

38·2 to 57·2

38·0 to 62·3

34·5 to 53·3

47·5 to 78·2

54·8 to 82·0

43·5 to 68·7

39·5 to 59·5

31·0 to 62·5

4·0 to 52·0

39·0 to 62·6

56·0 to 71·0

41·5 to 56·0

63·0 to 60·0

54·0 to 67·8

68·2 to 78·0

58·0 to 66·0

58·7 to 67·8

56·2 to 65·0

52·0 to 61·0

49·7 to 55·2

36·0 to 52·8

34·5 to 53·3

46·0 to 61·3

48·5 to 65·8

Himalayan Journals — Complete Or, Notes of a Naturalist in Bengal, the Sikkim and Nepal Himalayas, the Khasia Mountains, etc. · 第 31 / 32 章

My observations for temperature and wet-bulb being for the most part