Directory_and_Chronicle_1841 — Page 370

THE

CHINESE REPOSITORY.

VOL. X.-JULY, 1841.- No. 7.

ART. I. Meteorological observations made at the island of Chusan

from the month of September, 1840, to February, 1841. THE barometer employed was one of Newman's mountain barometers; the difference between which and the standard barometer at the observatory, Cape of Good Hope, was + 0.014 inches. The elevation of the cistern above the level of the sea during the month of September was 72 feet, during which time the observations were made on a point at the western extreme of the har- bor, opposite to a small island called Guardhouse island in Thornton's chart, and Seaou-chuk san by the Chinese. The subsequent months the observa- tions were made in a house at the western extreme of the suburbs, where the level of the cistern was 21 feet above the mean tidal level. The temperature of the air in the shade was ascertained by a box-wood thermometer (Fah- renheit's scale), close to which was placed a similar one, with a piece of cotton attached to the bulb, which was kept moist and registered at the same period to show the degree of dryness in the atmosphere. The observations for radia- tion were made with similar thermometers, the bulbs of which were ex- posed to the sun's rays, one of them blackened by indian ink. A self-regis- tering thermometer was placed near to the shade thermometer, and the maximum and minimum temperature registered every morning. The rain guage during the month of September was a copper cube of 6 inches, which was surrounded with straw to check the evaporation. Upon the removal of the instruments to the suburbs, one of the rain guages supplied by H. E. the Governor-general was obtained. The register in the table indicates the actual measurement daily, (the rain guage never being emptied.) The observations during the month of September were made by Mr. W. H. Symonds mate of H. M. S. Blenheim, and subsequent to that period by Mr. A. Roger of H. M. S. Blenheim. The hourly register on the 21st of each month was taken in accordance with the directions of the committee for the antarctic expedition and magnetical observatories.

VOL. X. NO. VII.

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