Page:A Voyage of Discovery and Research in the Southern and Antarctic Regions Vol 2.djvu/98

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, the mean temperature due to the middle of the month of March is 43°·9, and the average range is from 66° to 24°. The first month of Spring in New Zealand has therefore a higher temperature by ten degrees than that of England; and, although, the maximum temperature in both is the same, yet the climate of New Zealand is free from those severe frosts which frequently do so much mischief to advanced vegetation in England.

The mean temperature of the dew point, as derived from observations made four times each day, viz.; at 3$h$ and 9$h$, and 3$h$ and 9$h$ , by Mr. Lyall, assistant-surgeon of the Terror, was found to be 49°·6; the amount of dryness is therefore 4°·3; the degree of moisture of the air is ·862; and the elasticity of vapour is equal to 0·395 inches. The quantity of rain which fell 11·76 inches, and the greatest fall occurred between 2 on the 8th, and 2  on the 9th September, amounting to 5·5 inches; the barometer during the time being below its mean height, and the wind fresh from the northward: so far, therefore, as regards the moisture of the atmosphere, there is very little difference between the first spring month of England and of New Zealand, the degree of dryness in England being 4°·9, the moisture of the air ·831, the elasticity of vapour ·272, but the quantity of rain amounts to only 1·44 inch.

The mean height of the barometer is 30·034, and its range 1·14 inch. The diurnal variations of pressure, commonly called the atmospheric tides,