650 SUPPLEMENT TO THE HONGKONG GOVE GAZETTE OF 25TH JULY, 1885.
At 10 a. on the 19th, the centre was in 15° 19′ N, 118° 40′ E. A moderate ESE gale was reported from Bolinao. A fresh NE gale blew at S. Cape (Formosa), where the sky was overens: Moderate E and NE breezes blew along the Coast of China, and c-cum from S were observed in Hong- kong. Strong NW breezes or moderate gales are reported by ships W and SW of the typhoon.
At 10 a. on the 20th, the centre was in 15° 45′ N, 116° 16′ E, and at 10 a. on the 21st in 14° 52′ N, 114° 10′ E. On the latter day it blew a strong gale 250 miles NE of the centre, and a whole gale 350 miles SW of the centre. Rain fell in squalls, 300 miles NW of the centre.
It rained Within continuously within 100 miles of the centre, and the rain fell in torrents within 50 miles. about 60 miles at the centre the wind blew with typhoon force, and within 10 miles the air was calm. The S.S. Benarty, which was in the central calm at 6 a. on the 20th reports, that many small birds dropped on deck, but makes no mention of the sky clearing at the time. The sea was mountainous and confused. This steamer lost its funnel and sustained other great damage.
The isobars appear, as far as can be judged from the observations, to have been elliptical, the In front the wind made an major axes being situated in about the line of progression of the centre. angle with the gradients of 62° in the right hand quadrant, and 52° in the left hand quadrant, or on an average 57°. In rear the wind made an angle of 29° in the right hand quadrant, and probably abont the same in the left hand quadrant, but here no ships' logs are available. These results are derivel from the observations within 250 miles of the centre. Within 100 miles of the centre in the rear, the angle appears to have had a value more nearly equal to the angle in front. This result, derived prin- cipally from observations made on the open sea, agrees well with the theory. The typhoon was propelled by the NE winds, and proceeded at a very constant rate, keeping the high pressures on its The different results right. The angle on the left side was smaller owing to the lower latitude. obtained in case of typhoons near the coast of China may be explained from the effects of friction near the surface of the earth. If sufficient observations of clouds were available in such cases, they would no doubt throw additional light on the subject.
The data available do not suffice for determining the proportion between the force of the wind and the gradients, but the following figures are approximately correct: It blew a moderate gale (7), when the gradient was 0.02 inches in 15 miles, a fresh gale (8), when the gradient was 0.03, a strong gale (9), when the gradient was 0.04, a whole gale (10), when the gradient was 0.05, a storm (11), when the gradient was 0.06 and with full typhoon force (12), when the gradient exceeded the latter figure. The average temperature in Bolinao, when the typhoon was passing, was nearly 80o. At sea it appears to have been about 72°.
At 10 a. on the 22nd, the centre appears to have been in 13° 15′ N, 112° 34′ E, and at 10 a, on the 23rd in 11° 25′ N, 111° 24′ E. It cannot be traced further than this, but I am informed, that great loss was sustained by steamers carrying bullocks, by high seas in the entrance to the Gulf of Siam. Strong NE winds and rather high seas obtained during the remainder of the month in "the
China Sea.
The Barograph and the Standard Barometer at the Observatory are placed at 110 feet above Mean Sea Level. The bulbs of the Thermograph Thermometers are 111 feet above Mean Sea Level and 6 feet above the ground. They are exposed in an unpainted and double-louvered zinc screen fixed to the north wall of the main building in a shaded position. The Solar Radiation Maximum Thermomne- ter is 109 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 above Mean Sea Level, and the rim, which is 114 inches in diameter, is 21 inches above the ground. The cups of the Anemograph are 45 feet above the ground, and 150 feet above Mean Sea Level.
out.
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 above the floor, except the Maximum Thermometer, which is a few inches higher. The Radiation Thermometers are placed at the same height above the ground as at the Observatory. At Cape d'Aguilar the Thermometers are placed about 170 feet above Sea Level (according to the Governmea Gazette) in a wooden screen 2 feet above the ground, except the Maximum Thermometer, which is a few inches higher.
Table I exhibits the hourly readings of the Barometer reduced to 32°.0 Fahrenheit, but not to Sea Level, as measured (at two minutes to the hour named) from the Barograms. The Mean Height of the Barometer was 29.996, the Highest was 30.205 at 9 a. on the 26th, and the Lowest was 29.860 at 4 p. on the 4th. The Barometric Tide amounted to 0.097.
as measured
Table II exhibits the hourly readings of the Temperature (Dry Bulb Thermometer) as from the Thermograms (at two minutes past the hour named), and also the Extreme Temperatures during the day. The Mean Temperature was 67.8, the Highest was 83.1 at about 3 p. on the 1st.
and the Lowest was 51.3 at about 6 a. on the 23rd.