670915-1885-Weather-Report-December-1884- — Page 1

SUPPLEMENT

To the HONGKONG GOVERNMENT GAZETTE of 1st August, 1885.

GOVERNMENT NOTIFICATION.-No. 307.

The following report from the Government Astronomer, for the month of December, 1884, is published for general information.

By Command,

Colonial Secretary's Office, Hongkong, 1st August, 1885.

HONGKONG OBSERVATORY.

Weather Report for December, 1884.

FREDERICK STEWART,

Acting Colonial Secretary.

In the China Coast Meteorological Register, based on information transmitted by the Great Northern and the Eastern Extension Telegraph Companies-which I have published daily, is given a summary of the atmospheric circumstances in Manila and along the Coast of China between Haiphong and Shanghai. It also contains information concerning the weather in Nagasaki and Wladivostock, and the first appearance and progress of Typhoons.

At the end of November and in the beginning of December strong NE gales blew over the China Sea. The barometer reached a maximum 30.01 at 10 a. on the 7th in Manila. On the morning of the same day it blew a fresh NE gale with drizzling rain at S. Cape (Formosa). At 10 a. on the 8th, the barometer had fallen to 29.98 at Manila and a light NNW breeze was reported from Bolinao. At this time the centre of typhoon XIX may have been about 13° N, and 123°-124° E. The barometer was falling along the Coast of China. Gradients indicated fresh N winds. The temperature had risen in the south, and the air was very dry. At 8 p. the height of the barometer was 29.78 and a gentle or moderate N breeze blew at Bolinao.

At 5h. 30m. a. on the 9th, the height of the barometer was 29.86, and the breeze had veered to NE at Bolinao. The fall in the barometer continued along the coast, particularly in the SE. Fine and dry weather accompanied by NE gales prevailed over the China Sea. At 10 a. the height of the barometer was 29.91 at Manila. The centre of the typhoon may have been in 12°-13° N, and about 121° E.

At 5 a. on the 10th it blew a moderate N gale at Bolinao, the clouds came from NE and the barometer was rising. It was steady along the coast. Gradients indicated more moderate NE winds. The centre of the typhoon was probably in about 11° N, 118-119° E at 10 a. A moderate NNE gale was reported from Bolinao at 4 p. The South Cone was hoisted at 12h. 40m. P., and was taken down next day at 12h. 30m. p.

At 10 a. on the 11th the typhoon had disappeared. Most likely it was moving SWestward. Gentle NE winds and fine weather with blue sky were reported from all stations between Tonquin,

Luzon and Wladivostock.

The increased speed of the progressive motion of typhoons with increasing geographical latitude, et forth in my report of the 16th July, 1885, (Appendix M), is probably connected with the corres- ponding increase of barometrical depression. In a typhoon in the China Sea the pressure falls seldom much below 29.00 inches, and it falls frequently much more after reaching a higher latitude. The consequently steeper gradients in a higher latitude apparently increase the progressive speed although the corresponding maximum force of the wind is at least near the surface of the earth, considerably

s than within the tropics.

The Barograph and the Standard Barometer at the Observatory are placed 110 feet above Mean Level. The bulbs of the Thermograph Thermometers are 111 feet above Mean Sea Level and 6 bet above the ground. They are exposed in an unpainted and double-louvered zinc screen fixed to the th wall of the main building in a shaded position. The Solar Radiation Maximum Thermometer is feet above Mean Sea Level and 4 feet above the ground, and the Terrestrial Radiation Minimum Thermometer is about one inch above the ground. The self-recording Rain-gauge is placed 106 feet ve Mean Sea Level, and the rim, which is 114 inches in diameter, is 21 inches above the ground. of the Anemograph are 45. feet above the ground, and 150 feet above Mean Sea Level. At Victoria Peak the Instruments, except the Radiation Thermometers, are placed in the Look- The Barometer is 1821 feet above Sea Level. The bulbs of the Thermometers are about 4 feet ve the floor, except the Maximum Thermometer, which is a few inches higher. The Radiation mometers are placed at the same height above the ground as at the Observatory. At Cape Aguilar the Thermometers are placed about 170 feet above Sea Level (according to the Government e) in a wooden screen 2 feet above the ground, except the Maximum Thermometer, which is a inches higher.

cups

Table I exhibits the hourly readings of the Barometer reduced to 32°.0 Fahrenheit, but not to Level, as measured (at two minutes to the hour named) from the Barograms. The Mean Height