Sessional_Paper_1885-1886 — Page 190

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Table XIV exhibits the amount of cloud, which is greatest in the morning and least in the evening. It reached its maximum in February, during which the sky was almost continuously over- cast, and decreased then slowly till December, when it reached its minimum.

Table XV exhibits the sea-disturbance, which was greatest in January and February, when the force of the wind was highest and least in September, together with the wind force.

Table XVI and Table XVII exhibit the extremes of the principal meteorological elements at the Observatory and at the Peak respectively.

Table XVIII exhibits the mean readings of the black bulb thermometers at the Observatory and at the Peak. The readings published in the Observations and Researches for 1884 and in the monthly reports for 1885 were reduced to the standard kept at Kew by applying a constant correction. In 1885 however comparisons were made at different parts of the scale by the intermediary of a black bulb ther- mometer whose corrections were investigated at both Observatories, and it was ascertained, that the readings as published for the Peak should be increased by 2o.0, the correction being sensibly constant, and that the following corrections should be applied to the readings as published for the Observatory :-

At 90°

100°

>>

110°

>>

-

2o.4

0°.8

+ 0°.5

At 120°

130°

140°

+ 1°.5

+ 2°.3

+2°.9

These corrections have been applied to the data published in this, the annual report for 1885, and corrections to readings above 140° have been extrapolated. It should be remembered that these cor- rections do not by any means improve the accuracy of the observations but simply render them comparable with those made at Kew and at Observatories, whose black bulb thermometers have been compared there. A great number of readings of black bulb thermometers have lately been published from Ceylon. These would be comparable with those published elsewhere, if the thermometers were compared. The thermometers distributed among the Imperial Maritime Customs' stations have been compared here and observations were started last year at a great number of stations. But of course records of black bulb thermometers are not very important.

The highest mean of black bulb temperature occurred in September, at both stations. The greatest mean excess above mean maximum air temperature in September, at the Observatory and in October, at the Peak. When the clouds are low this excess is greatest at the Peak, when they are high it is greatest at the Observatory.

The same table shows the mean excess of minimum air temperature above the minimum on grass. In March, the grass minimum at the Peak did not register lower than the minimum owing no doubt to the fog. The greatest difference was registered in November, at both stations.

But those figures do not exhibit a measure of the terrestrial radiation, as the grass minimum gets wet from fog and rain, and it is most probable that its temperature is depressed more from this cause than by radiation. The greatest radiation is registered in November, which coincides with the greatest dryness of the air, as might be expected, but just at that time the least trace of dampness on the ground would lower the readings enormously, and it is remarked that the lowest readings of the grass minimum are obtained when the sky clears with a dry northerly wind just after a slight fall of rain. For these reasons I feel inclined to doubt, whether the grass minimum is of any value at all for registering terrestrial radiation. But it indicates roughly the lowest temperature on the grass.

The same table shows the average weight of aqueous vapour in Troy grains in each cubic foot of air at the Observatory and at the Peak.

The same table exhibits the mean diurnal range of temperature at the Observatory and at the Peak, which is of course greater than the range that follows from the hourly readings.

The same table shows the height to which one must ascend in order to have the mean temperature lowered one degree, the figures having been calculated from the data in Table II. This is greatest when the clouds are low.

From a return furnished by the Registrar General it is seen that the mean monthly death-rate per thousand among the Chinese in Hongkong from Zymotic diseases was 1.067 in 1884 and 1.384 in 1885, and from diseases of the Digestive Organs 0.059 in 1884 and 0.081 in 1885. The maximum monthly death-rate from the former diseases occurred in September, 1884, (1.413) and in July, 1885, (2.966) and the minimum in February, 1884, (0.749) and in January, 1885, (0.670). The maximum monthly death-rate from the latter diseases occurred in October, 1884, (0.099) and in July and October, 1885, (0.112) and the minimum in December, 1884, (0.026) and in February, 1885, (0.046).-The mean monthly death-rate per thousand from diseases of the Skin was 0.065 in 1884 and 0.043 in 1885 and from diseases of the Respiratory Organs 0.213 in 1884 and 0.237 in 1885.

The effects of the increased strength of the S monsoon in 1885 appear thus in the increased death-rate from various diseases.