APPENDIX VI.

Observations of Temperature below and upon the Camaroons Mountains, kept by M. Gustav Mann, Government Botanist, West Africa, and Selim Aga, between the 6th December, 1861, and the 24th February, 1862.

The instruments used were two Bath Thermometers, Negretti and Zambra, London (patent, Nos. 1064 and 1063, graduated to 110° and 180° Fah.), suspended near camp with a south-westerly aspect: one,—the first of the double observation—in the sun; the other, the second, in the shade; both 3½ feet above the ground. The maximum and minimum were Nos. 2697 and 1764 of Messrs. Negretti and Zambra. In the minimum the alcohol was at first red; it presently paled to a dull straw yellow. In the remarks I have used a small pocket thermometer (Fah.) by Messrs. Cary, London.

The correction for No. 1064 (sun therm.) is at 32° − 0·1

„ „ at 42° − 0·1

„ „ at 52° − 0·1

„ „ at 62° + 0·1

„ „ at 72° + 0·1

„ „ at 82° correct.

„ „ at 92° − 0·2

The correction for No. 1063 (shade therm.) is at 32° − 0·1

„ „ at 42° − 0·4

„ „ at 52° − 0·5

„ „ at 62° correct.

„ „ at 72° − 0·4

„ „ at 82° − 0·4

„ „ at 92° − 0·4

The maximum and minimum are correct.

Date. 6 A.M. Noon. 6 P.M. Wind. Max. Self Regist. Min. Self Regist. Remarks.

Dec. 61. ° ′ ° ′ ° ′ ° ′ ° ′

6 { 84 50 75 50 } 84 50 M. Mann landed at Victoria. Base of the mountain. Cloudy day, strong sea-breeze.

96 77

7 { 70 50 85 50 80 } 86 71 50 Do.

72 50 104 80 50

8 { 74 85 80 } 86 73 Do.

74 50 105 81

9 { 71 50 84 74 } 85 25 72 Warm and sunny.

73 85 50 75 50

10 { 67 50 84 82 } 85 75 67 50 Do.

69 95 82

11 { 70 50 83 75 82 } 86 50 70 50 Do. Heavy thunderstorm, without wind, at night

71 50 94 82

12 { 71 85 50 80 50 } 85 25 70 50 First half of day cloudy, then clear.

71 50 98 81

13 { 72 75 72 } 72 At Bosumbo. Warm, clear day.

73 73 75

14 { 67 50 78 25 72 } 79 50 66 50 At ditto. Rain.

69 85 25 73 25

15 { 65 50 65 50 } 65 At Mapanya. Sunny day.

66 50 69

16 { 59 50 76 75 65 50 } 72 50 59 50 At do. Clear and sunny.

60 50 78 50 69

17 { 60 50 } 61 On mountain. Hazy, smoky, and misty.

62

18 Dies non. On ditto. Cloudy as usual. At Victoria fine, clear, and warm.

19 { 77 50 64 75 } Sea-breeze. Began by march up the mountain to Mapanya. Clear and hot.

75 68 75

[152]

20 { 60 75 69 } At Mapanya. Fine clear day.

63 75 71

21 { 62 25 78 } Left Mapanya; reached Ridge Camp. Hot day; cold night.

62 76 25

22 68 50 E. 40 Ascended hill. At 8·30 Therm. 80°. Wet day. Cold wind from E. At 4·45 P.M. Therm. 60°.

23 48 S.W. At 8 A.M. mist from S.W., Ther. 68°. At 10 A.M., in sun, 92°; shade, 85°. At 11 A.M., cloud and wind, 72°. At noon, sun and cloud, 84°. At 1 P.M., misty, in sun 91°. At 4 P.M., in the forest, 66°. Night very pleasant.

24 { 53 63 50 55 66 } N. & N.E. Strong. Cloud at 8 A.M. On Mount Helen, Therm. at 8·30 A.M., 57° 5′-58° 5′, a few feet below. At 11 A.M., in camp, Therm. 66°.

53 25 60 75 55 66

25 { 50 50 61 53 50 } Very fine day.

51 50 60 25 55 50

26 { 50 54 } N.E. & S.W. At 2 P.M. very thick mist from W. like rain. Carried off by N.E. wind.

52 55

27 { 48 66 50 54 } N.E. At 5·30 A.M. Therm. 48°, very little dew. On Mount Isabel at 5 P.M., 40°.

48 50 66 75 54 75

28 { 49 50 61 50 52 } N.E. & S.W. At 3 P.M. few drops of rain. Wet and misty day. At night Venus veiled. Cold night.

49 50 60 50 53 50

29 { 50 50 60 53 } Do. 64 49 Misty morn and day. Threatened rain, none came. Loud thunder at night from W. and S., but below gusts of wind. Cold at times.

50 50 60 54

30 { 50 75 56 50 } N., W. & E. 63 50 49 75 Cold, raw morning, 54° at 8 A.M. Raw and misty till noon, then hot sun. Heavy cloud in W.; kind of Harmattan day. Wind from all quarters. Clouds torn to pieces.

51 56 50

31 { 49 60 57 50 } E.S. & S.W. 61 49 75 Very cold wind all night.

49 75 60 58 50

Jan. 62.

1 { 49 50 58 25 } N.E. & S.W. 66 50 49 75 Cold morning. Normal day. Misty day.

50 50 58 75

2 { 52 60 75 56 25 } S.W. & N.E. 52 Thunder in morn. Day cool, misty and still. Even. fine, warm, and windless.[153]

52 75 60 75 56 25

3 49 61 54 Do. Hazy morn. Dry hazy noon. At 2 P.M. misty, and a few drops of rain. Warm and clear at 3 P.M. Misty even. This and the next day’s obs. are with 1064 Therm. placed in sun.

1 P.M.

4 48 50 66 55 25 Do. Misty morn. and even. Clear noon.

5 { 47 57 } Do. Cool, clear morn. Day misty. Fine and windless evening. At 3·40 P.M. little rain from W.

47 57

6 { 49 64 55 50 } Do. 72 5 45 Fine, clear day.

49 63 55

7 { 48 70 54 } Do. Day changing. Sun and mist alternately. Clouds heavy in W. From 3 P.M. till night clear and light. Night cold.

51 75 64 75 53 50

8 { 50 83 58 } Do. Fine clear morn. Raw cloudy day. In afternoon hot sun. Beautiful even.

51 68 25 56 50

9 { 50 50 59 25 55 } Do. Clear morn. Heavy mist. At 11 A.M. few drops of rain (2nd time). Raw and cold. Weather seems breaking.

50 58 75 55 50

10 { 49 74 55 25 } Do. 41 At 5·30 A.M. 47°. Heavy thunder and lightning at night almost overhead. Morn. clear. Mist at 10. All night thunder and clouds from S.W. came overhead.

50 68 55 50

5·30 A.M. 6·30 P.M.

11 47 58 52 No wind. Morn. cool and clear. Mist at 10 A.M. Thunder and lightning in S.W. At 4 P.M. mild and pleasant. Cold night. Therm. 1064.

12 { 47 68 55 } Land-breeze N.E. Very fine still morn. Thunder below. Cold mists at 10 A.M. till 3 P.M.; warmer after noon. Cold, clear night.

47 50 61 55 50

13 { 49 57 75 54 } N.E. & S.W. Splendid morning. Cool, clear, and still. Raw mist 11 A.M. to 2 P.M. Still warm even.

47 57 25 54 50

14 { 49 68 54 25 } Do. Morn hazy and still. Mist 10 A.M. to 4 P.M. At noon few drops of rain. Fine clear even. Bright stars.

51 50 65 50 54 75

15 { 48 64 56 50 } N.W. & S.W. N. wind about dawn; W. till 10 A.M., then S.E. sea-breeze. Meridian obs. taken at 1 P.M. Mist condensed by cold. Dull, but still even. Cold night; gusty near morn.

50 61 50 57

16 { 51 50 62 56 } N.E. & S.W. Misty day. Very calm in even. Fine night. Clear moon. Heavy dew.

53 61 56

5 A.M. 1·30 P.M.

17 { 49 59? 50 52 75 } Do. Thunder in morn. Dull, misty day. In even. clouds. Stars obscured. Meridian obs. at 1·30 P.M.

50 58 50 53 75

18 { 49 25 70 50 55 } Do. Morn. Thun., dry and fine. Wind S.W. at 8 A.M. Fine clear view of sea at 5·45 P.M. Leaves falling. Swarms of swifts. Hawks cry at night.

50 65 75 55 50

5 A.M. 1·30 P.M.

19 { 51 50 75 55 50 } all round compass. First heavy storm. See diary. Meridional observation at 1·30 P.M.

52 75 66 50 55 50

20 { 50 67 50 59 50 } S.E. Fine clear morn. Ditto day. Sharp cold S.E. wind till night. At 4 P.M. hot sun. Little mist. Clear moon. Bees swarming from east to west.

51 70 75 58 50

7 A.M.

21 { 51 66 50 53 } N.E. & S.W. Morn. obs. at 7 A.M. Fine, clear. Wind less. Italian weather. At 7 A.M. thunder from N.W. At 10 A.M. very heavy mist. 2 P.M. distant thunder clap from N.W. At 3 P.M. few drops of rain. Clearer in even. Night thunder from W. by N.W. Bees still swarming.

52 65 50 53 50

22 { 50 50 52 50 54 } N.E. etc. Bad thunder storm. See diary. Snow seen from below mountains.

52 52 50 54

5 A.M. 45m. P.M.

23 { 50 50 59 53 50 } N.E. & S.W. Morn. obs. at 5 A.M. Fine, clear, and cold till 10 A.M. Then mist from every direction. Thunder westward, 3 P.M. Therm. on ground near Calvo Crater, in sun, 82°, when mist came over, 74°.

51 50 58 54

4 A.M. 2 P.M.

24 { 50 65 55 } E. strong. Morn. obs. 4 A.M. Noon, 2 P.M. Dull morn. Little Camaroons clearly seen. Heavy mist from below. Cold, and hot sun. Threatened rain, but none fell. Calm even. Heavy thunder at night.

50 50 62 25 54 75

30 P.M.

25 { 48 72 53 75 } N.E. & S.W. Clear morn. Misty day and even. Thunder and lightning below. Fine cool night.

49 69 50 54

5·30 A.M.

26 { 49 65 53 50 } W. & S.E. Thunder all morn. Day misty and fine by turns. Clear even. Thunder and lightning at night.

49 62 50 54

2·30 P.M.

27 { 48 50 80 50 43 } Do. Slept on Mount Isabel. Morn. cold, dear. Mists at 10 A.M. Heavy clouds from E. At 4 P.M. therm. 45°. Rain-drops at 2 P.M. Heavy dew. At 5·50 P.M. 45° and 44°.

49 50 78 43

11 A.M.

28 { 39 75 51 50 41 50 } Do. Morn. and even. obs. in Isabel and Saker’s Camp. Noon on mountain. Dull red morn. Cold, and few clouds at sunrise. Slept at Saker’s Camp.

40 51 50 41 50

29 { 39 80 42 } Do. Hoar frost in morn. At 2 A.M. 37°. Grey and cold. Sun not visible till high up. Slept at Saker’s Camp.

39 60 42

30 { 36 } Do. Hoar frost on clothes. At 2 A.M. 32° 50′. Bad thunder from S.W. A vile day, with rain and hail. Descended to Mann’s Spring. See diary. New moon, bad omen. M. Mann’s maximum on summit of Albert Crater, 55°., minimum 27°. At time of inspection 35°.

36

31 { 52 75 57 } Do. Left Mann’s Spring, and began the descent. At sunrise next morning, therm. 46°.

53 67 58

I then left the mountain, and soon found myself in an atmosphere of 80° F.

M. Mann.

Feb. 62.

1 { 49 56 50 } N.E. Clear in morn. and noon. Even. very strong wind. Max. 71°. Min. 50°.

50 5 57 50

2 { 48 56 } Do. Morn. clear and still. 8 A.M. wind rose. Thunder. Clear afternoon. Max. 71°. Min. 48°.

49 75 57

3 { 51 50 55 } Do. Cloudy and warm. Max. 71°. Min. 50°.

53 56 25

4 { 50 52 } Do. Wind light. Sunny and cloudy by turns. Max. 69°. Min. 49°.

52 54

5 { 51 53 } Do. Calm. Morn. and even. clear. Cloudy at midday. Max. 66°. Min. 48°.

52 54

6 { 52 68 54 } Do. 68 50 48 Wind light. Distant thunder from sea. Cloudy and sunny day by turns.

53 65 54 50

7 { 49 84 52 50 } Do. 63 50 49 Wind light. Sunny and cloudy by turns.

50 72 75 54 25

1 P.M.

8 { 50 50 61 50 51 50 } Do. 63 50 49 Morn. clear and calm. Day and even. cloudy.

52 50 60 53

9 { 52 69 58 25 } Do. 68 48 Strong wind. Cloudy.

52 50 68 50 59 25

10 { 50 50 73 50 59 } Do. 72 50 51 Sunny and warm. Very pleasant. Even. clear. Thunderstorm and rain at night.

52 50 85 58 50

11 { 51 59 50 54 50 } N.E. 67 75 49 Foggy till 3·0 P.M. Then two hours sun. After 5 P.M. sky covered.

52 25 60 55 50

12 { 52 62 52 50 } Do. 64 90 Rain and calm in morn. Clear and calm day.

52 50 62 53 50

13 { 51 } Do. 48 50 Clear morn. Calm and covered sky in day.

52 50

14 { 64 60 } all round. 69 M. Mann travelled to Ridge Camp this day. At 5 A.M. heavy tornado. Cloudy and rainy day.

64 50 60 50

15 { 63 25 67 65 50 } Do. 69 60 Cloudy day. Dry at Ridge Camp.

64 67 50 66 50

16 { 64 66 62 50 } Do. 67 50 63 50 Ridge Camp. Rain all day.

64 50 66 75 63

17 { 63 67 67 } Do. 71 50 61 Day warm and sunny.

63 69 50 67 50

18 { 64 80 } Sea-breeze. 63 Descended to Victoria, where even. obs. taken. Day sunny and warm.

64 81 50 R.C.

19 { 73 50 75 73 } Sea-breeze (strong.) 78 50 70 50 Rainy day.

74 25 75 50 74 50

20 { 66 88 50 78 50 } Do. 87 67 Day sunny and cloudy. Warm and dry.

67 50 87 80

30m. P.M.

21 { 69 100 81 } Sea-breeze strong. 90 69 50 Sunny and warm.

70 90 82

22 { 73 95 79 } Do. 88 50 72 Morn. sunny. Afternoon cloudy.

73 85 25 79 50

23 { 70 75 100 80 } Do. 90 71 Day warm and sunny. Thunder in the mountains at noon. Cloudy for 1h. 30m.

71 75 86 50 81

24 74 50 73 M. Mann left Victoria on his way to Camaroons.