Page:Madras Journal of Literature and Science, series 1, volume 6 (1837).djvu/347

1837.] a little quicker in its motions, which occasioned it being found a degree or a degree and a half higher in summer and as much lower in winter, than the quicksilver in the larger thermometer. The difference between the heat of the air warmed by the direct rays of the tun, and that within doors was on an average 18 degrees; whenever it was remarkably greater, notice will be taken of it. The observations were made at 7, 2 and 7  The highest degree of heat generally occurred at 2 , soon after which period, the sea breeze had fully set in at Perth, and the thermometer commenced to descend. The height of the thermometer at a medium is calculated from its average height at these different hours. The barometer was included in the same case with the thermometer, the whole made by Cary of London. It was occasionally heard that the barometer rose a little before wet weather, but this was an exception to the general rule. I regret the want of an hygrometer prevented upon me from ascertaining the exact dryness or humidity of the atmosphere; but this deficiency is in some measure supplied by the number of rainy days being noted, as well as by extracts from the register of the pluviameter kept by my friend A. Colin, Esq. Colonial Surgeon at Garden Island and Perth—for which see Table at the end.

1830, March.— Was fine for the most part, a little rain fell on the 11th, also on the 24th, at new moon; heavy rains on the 18th, lightning and thunder on 31st; prevalent winds E.— N. and N. E.

April.—Early part cloudy and showery, middle fine, latter end cloudy; showers fell on 1st, 4th, 5th, 6th, 7th, 16th, 24th, 27th and 30th; lightning and thunder on 16th, 22d, 24th and 27th; winds N. W.— S. W. and N. E.

May.—Fine till 13th, when some rain fell in the evening, preceded by thunder and lightning; on the 14th very loud thunder and lightning with much rain; on 15th (last quarter moon) 20th and 21st heavy rains; a gale of wind on 21st from the south-west, which did much mischief