Himalayan Journals, vol 2 by J. D. Hooker (android pdf ebook reader TXT) 📕

Sunrise 9 a.m. 3 p.m. 9 p.m.

TEMPERATURE

Mean 65.3 81.6 88.1 71.1

Max. 69.0 82.5 90.0 76.0

Min. 57.5 79.5 84.5 68.0

Range 11.5 4.0 5.5 8.0

WET-BULB

Mean 57.7 65.3 63.3 60.3

Max. Depression 8.0 19.0 26.5 13.0

Min. Depression 6.0 14.0 21.5 8.3

Elasticity of Vapour .428 .468 .324 .433

DEW-POINT

Mean 52.0 54.5 43.7 52.3

Max. 55.5 57.9 47.8 56.7

Min. 45.9 49.0 37.9 46.8

Max. Depression 14.1 33.0 46.6 21.9

Min. Depression 11.6 12.9 42.2 13.8

Weight of Vapour in cubic feet 4.710 5.000 3.417 4.707

SATURATION

Mean .647 .421 .240 .542

Max. .741 .479 .295 .643

Min. .648 .344 .214 .491

Number of observations 4 3 3 4

Extreme variations of Temperature 32.5 degrees

Extreme variations of relative humidity .527

Extreme diff. Solar and Nocturnal Radiation 110.5 degrees

NOCTURNAL RADIATION

SUNRISE

Exposed Th. On Earth On Grass

Temperature 59.5 56.0 54.7

Mean Diff. from Air 3.5 1.5 8.2

Max. Diff. from Air 3.5 1.5 8.5

Number of Observations 2 1 2

NINE P.M.

Exposed Th. On Earth On Grass

Temperature 71.5 62.5 61.0

Mean Diff. from Air 3.3 5.5 8.2

Max. Diff. from Air 7.0 5.5 11.0

Number of Observations 3 1 2

The rapid drying of the lower strata of the atmosphere during the

day, as indicated by the great decrease in the tension of the vapour from 9 a.m. to 3 p.m., is the effect of the great violence of the

north-west winds.

From the few days' observations taken on the Kymore hills, the

temperature of their flat tops appeared 5 degrees higher than that of the Soane valley, which is 500 feet below their mean level. I can

account for this anomaly only on the supposition that the thick bed of alluvium, freely exposed to the sun (not clothed with jungle),

absorbs the sun's rays and parts with its heat slowly. This is

indicated by the increase of temperature being due to the night and morning observations, which are 3.1 degrees and 8.5 degrees higher

here than below, whilst the 9 a.m. and 3 p.m. temperatures are half a degree lower.

The variations of temperature too are all much less in amount, as are those of the state of the atmosphere as to moisture, though the

climate is rather damper.

On the subject of terrestrial radiation the paucity of the

observations precludes my dwelling. Between 9 p.m. and sunrise the

following morning I found the earth to have lost but 6.5 degrees of heat, whereas a mean of nine observations at the same hours in the

valley below indicated a loss of 12 degrees.

Though the mean temperature deduced from the few days I spent on this part of the Kymore is so much above that of the upper Soane valley, which it bounds, I do not suppose that the whole hilly range

partakes of this increase. When the alluvium does not cover the rock, as at Rotas and many other places, especially along the southern and eastern ridges of the ghats, the nights are considerably cooler than on the banks of the Soane; and at Rotas itself, which rises almost

perpendicularly from the river, and is exposed to no such radiation of heat from a heated soil as Shahgunj is, I found the temperature

considerably below that of Akbarpore on the Soane, which however is much sheltered by an amphitheatre of rocks.

V. Mirzapore on the Ganges.

During the few days spent at Mirzapore, I was surprised to find the temperature of the day cooler by nearly 4 degrees than that of the

hills above, or of the upper part of the Soane valley, while the

nights on the other hand were decidedly warmer. The dew-point was

even lower in proportion, 7.6 degrees, and the climate consequently drier. The following is an abstract of the observations taken at Mr.

Hamilton's house on the banks of the Ganges (below).

It is remarkable that nocturnal radiation as registered at sunrise is much more powerful at Mirzapore than on the more exposed Kymore

plateau; the depression of the thermometer freely exposed being 3

degrees greater, that laid on bare earth 6 degrees, and that on the grass 1.4 degrees greater, on the banks of the Ganges. During my

passage down the Ganges the rise of the dew-point was very steady,

the maximum occurring at the lowest point on the river, Bhaugulpore, which, as compared with Mirzapore, showed an increase of 8 degrees in temperature, and of 30.6 degrees in the rise of the dew-point.

The saturation-point at Mirzakore was .331, and at the corresponding hours at Bhaugulpore .742.

MIRZAPORE (ELEV. 362 FEET), MARCH 9TH TO 13TH, 1848.

Hour Sunrise 9 a.m. 3 p.m. 9 p.m.

TEMPERATURE

Mean 61.1 76.1 86.0 76.0

Max. 63.0 83.0 ... ...

Min. 58.0 71.0 ... ...

Range 5.0 12.0 ... ...

WET-BULB

Mean 48.8 58.5 61.7 63.5

Max. Difference 51.5 56.5 24.3 12.5

Min. Difference 47.0 51.7 ... ...

Elasticity