10

In February, the last month of the winter quarter, the mean temperature at Malvern was of a degree higher than the mean temperature in London. The mean maximum at Malvern was 48.", the mean minimum, 37.4°; in London the mean maximum, 47.7°, the mean minimum, 37.1. The greatest height of the thermometer during the month, in London was 53.2°, in Malvern, 525°; the minimum in London, 27.9°, in Malvern, 28.5°. The maximum range in the former place, 25.3°, in the latter, 24.°

From the foregoing statement we perceive that the generally clouded state of the atmosphere, and the less altitude of the sun during the winter, prevent that accumulation of temperature which occurs in London, during the summer quarter especially, from the copious and varied reflections of heat from the sun's rays acting upon the pavements, buildings, &c. of a large city; while, doubtless, the numerous gas-lights, and the columns of heated air issuing from a vast accumulation of chimnies during the night, arrest the depression of temperature which would otherwise ensue from radiation. The former circumstance tends to equalise the condition of the two places during the day; and we find that, for the quarter under consideration, the mean maximum for each month in either place varies but little; the latter observation would tend to increase the mean minimum, and also the absolute minimum for each month-i. e. to prevent the depression of the thermometer during the night in London. Nevertheless, we see that, for the winter quarter, the mean temperature of Malvern is as high as the mean temperature of London.

In March, the first month of the spring quarter, the mean temperature at Malvern was of a degree lower than the mean temperature in London. The mean maximum at Malvern was 47.9°, the mean minimum, 37.o; in London the mean maximum was 48.3°, the mean minimum, 37 2°.

The maximum height of the thermometer during the month in London, 54.2°, in Malvern, 58°; the minimum in London, 32.7°, in Malvern, 31.°. The greatest range in London, 21.5°, in Malvern, 27..

In April, the mean temperature at Malvern was 1.4° lower than the mean temperature in London. The mean maximum at Malvern was 52.9°, the mean minimum, 41.6°; in London the mean maximum 55.8°, the mean minimum,42.4°. The maximum of the thermometer during the month, in London, 66.2°, the minimum, 30.°; the maximum in Malvern, 62.o, the minimum, 28.°. The greatest range, in London, 36.2°; in Malvern 34.

In May, the mean temperature at Malvern was 4.° lower than the mean temperature in London. The mean maximum at Malvern was 58.2°, the mean minimum 45.°; in London, the mean maximum, 62.5°, the mean minimum, 48°: The maximum of the thermometer during the month, in London, was 72.8°, the minimum, 41.7°, the maximum in Malvern was 66.°, and the minimum 37. The greatest range, in London, 31°; in Malvern, 29.° Hence we have for the spring quarter

In the month of April, the effect of the sun's rays begin sensibly to operate, the mean temperature in London being 1.4° higher than in Malvern, and this continues to increase throughout the month of May.

ATMOSPHERIC PRESSURE.

In December, the maximum of the barometer in London, (corrected as before) was 30.576, the minimum 29.215; the mean 30.265, and the range 1.361. In Malvern, the maximum 30.043, the minimum 28.611; the mean 29.700, and the range 1.432.

In January, the maximum in London, 30.759, the minimum 29.031; the mean 30.048, and the range 1.728. In Malvern, the maximum was 30.158, the minimum 28.359; the mean 29.445, and the range 1.799.

In February, the last month of the winter quarter, the maximum of the barometer in London was 30.417, the minimum 29.178; the mean 29.797, and the range 1.239. In Malvern, the maximum 29.876, the minimum 28.526; the mean 29.159, and the range 1.350.

Having paid much attention to the barometer, both in Malvern and at London, we may remark that on the MORNING of the 26th of January both instruments had fallen to the minimum of the month; but the barometer at Malvern was, for about two or three hours, unusually depressed, being in. below that in London, very heavy rain falling at the time: whilst at the same hours in London the weather was overcast, light rain, and light clouds. In the AFTERNOON, the barometer at Malvern had risen .250 in., and that in London .106: thus both, again, resuming their very nearly coincident indications. We may, also, observe that the dew-point, at the same period, was 4° higher in Malvern than in London : temperature the same.

In March, the first month of the spring quarter, the maximum of the barometer in London was 30.513, the minimum 28.797; and the mean 29.903, and the range 1.716. In Malvern, the maximum was 29.913, the minimum 28.192; the mean 29.274, and the range 1.721.

In April, the maximum of the barometer in London was 30.429, the minimum 29.475; the mean 30.077, and the greatest range for the month, .954. In Malvern, the maximum 29.873, the minimum 28.965; the mean 29.526, and the range .908.

In May, the last month of the spring quarter, the maxi

mum of the barometer in London was 30.123, the minimum 29.427; the mean 29.813, and the range .696. In Malvern, the maximum was 29.590, the minimum 28.850; the mean 29.243, and the range .740.

In March, (on the 7th) the minimum occurred at Malvern at 9 a. m.; in London, not until 3 p. m. At the former place were very heavy showers, with light wind; at the latter, lightly overcast, brisk wind. On the morning of the 8th they both again coincided. From this it would appear that the great atmospheric oscillations sometimes take five or six hours in their movement across the space dividing Malvern and London.

DEW POINT.

In December, the maximum dew-point was, in London, 53°, in Malvern also 53°; the minimum in London 33°, in Malvern, 32°; the mean in London 41.3, in Malvern 40°.

In January, the maximum in London 48°, in Malvern 48.5; the minimum in London 17°, in Malvern 21°; the mean in the former place 35.6°, in the latter 36.1°.

In February, the maximum dew-point in London was 45°, in Malvern 49°; the minimum in London 22°, in Malvern 30°; the mean in London 36.3°, in Malvern 38.6°.

In March, the first month of the spring quarter, the maxi

mum dew-point in London was 42°, in Malvern 50°; the minimum in London 29°, in Malvern 30°; the mean in London 36.5°, in Malvern 38.6°.

In April, the maximum dew-point in London was 51o, in Malvern 54°; the mininum in London 26°, in Malvern 25° ; the mean in London 41.3°, in Malvern 41.5.

In May, the maximum Dew-point in London was 56°, in Malvern 54; the minimum in London 40, in Malvern 39°; the mean in the former place 48.3°, in the latter 46.2°.

*These, and the tables of the wind previously detailed, we offer only as approximations: for, with westerly winds especially, the difficulty of determining, at Malvern, whether it is a little to the north or south of the due west point is almost insurmountable. In the former case, according to the sub-division before indicated (p. 223, vol. ii, of "The Analyst,") the current would be classed in the Dry, in the latter, in the Vapour column.