670645-1885-Weather-Report-September-1884- — Page 2

566 SUPPLEMENT TO THE HONGKONG GOVT GAZETTE OF 27 JUNE. 1885,

barometer all over the Far East from Manila to Wladivostock. On the 4th and the 5th gentle E breezes are reported by ships in the China Sea between 12° and 17° N. On the 6th the wind backed to NE in those latitudes, the fall in the barometer continued and is particularly noticeable at S. Cape. where it at 10 a. had fallen 0.08 inches since previous day. A gentic NNE breeze on the 5th increased to a strong breeze at midnight on the 7th and on the morning of the 8th. The weather had been fine and warm but on that day mist and rain set in.

On the 6th I remarked in the China Coast Meteorological Register, that the harometer was falling especially in the SE. The center of Typhoon XII was then East of Manila. At 10 a. on the 7th it may have been in 17° N, 1254° E. At the latter hour gentle NE breezes began to prevail along the SE coast of China and c-cum from N were observed the same day in Hongkong.

At 10 a. on the 8th the center appears to have been near the NE point of Luzon, in about 18° N, 123° E. A strong NNE breeze with misty weather blew at S. Cape, Formosa, a light W breeze with rain in Manila. Fresh northerly breezes with a swell in the sea from NE are reported by ships in the China Sea. Moderate N breezes with detached clouds prevailed in the Formosa Straits. Along the southern coast of China the sky was blue and the barometer had fallen about 0.05 inches. At S. Cape it had fallen 0.20 inches.

At 10 a. on the 9th the center appears to have been in 18° 30′ N, 120° 15′ E. It had apparently taken some time to cross the northern part of Luzon. A moderate NE gale with gloomy weather, mist and rain is reported from S. Cape. A moderate SSW breeze with mist from Manila, where the barometer had fallen to 29.65. Moderate NNW gales and rain with a high sea are reported by ships between Manila and Hongkong. Fresh NE breezes blew along the SE coast of China, where the barometer had fallen over a tenth of an inch and the sky had become overcast. A fresh NE gale is reported from the northern entrance of the Formosa Straits. The German Bark Johanna, at noon in 17° 41′ N, 115° 37′ E registered the barometer at 29.49 (reduced). By stearing towards SSW, Captain BANNAU avoided the Typhoon.

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At 10 a. on the 10th the center appears to have been in 19° 23′ N, 116° 0' E. A gentle SE breeze with rising barometer, but gloomy and misty weather is reported from S. Cape. A gentle SSW breeze from Manila, where the barometer had risen to 29.80. Strong NE brezes blew in the Formosa Straits, a fresh N gale in Hongkong. Moderate NW breezes with blue sky in Tonquin. At noon the Johanna in 16° 48′ N, 116° 48′ E experienced a moderate SSW gale with very high sea and squally weather and barometer 29.61 (reduced). The American ship C. F. Sargent, nearer Hongkong, encountered the full violence of the hurricane, blowing steadily from WNW between 6 p. and midnight. The barometer rose subsequently and the wind blew from SW with moderate force.

At 4 p. on the 10th the center was in 20° 5′ N, 114° 57′ E, moving N-Westward. At about 2 a. next morning it appears to have been within 47 miles SW of Hongkong and to have shortly afterwards passed within about 16 miles SW of Macao. The French Transport Drac at anchor north of St. John's Island was within 38 miles of the center, which passed in the NE, about 5 a., but did not experience above a moderate gale in this sheltered position. While passing between these places the center appears to have been moving N 33° W at a rate of 344 miles an hour. The isobars appear to have been elongated in the direction of the track of the center; gradients were evidently much stronger NE of the center, particularly in the part that crossed this Colony. Here some damage was done, particularly on shore, by the heavy rain, notwithstanding the warnings issued.

Those issued in connection with Typhoon XII are set forth in my report of the 24th September- (Appendix G). The table appended to that report exhibits the great fall of temperature, which, although principally due to the dense layer of clouds and to the rain, may have been partly effected by the sudden diminution of pressure and consequent expansion of the air, as suggested by HANN in his now famous paper on the change of temperature in ascending currents of air. It is noteworthy, that the relative humidity never rose to saturation in spite of the uninterrupted deluge of rain. The velocity of the wind was tabulated from the anemogram as explained in my Annual Report. It was found impossible to record the hourly direction of the clouds, and unfortunately the upper clouds cannot be observed near the center, owing to the presence and density of the lower clouds which surrounded the center and stretched out to a distance of 350 miles to the W and N of it. The area of heavy rain appears to have reached 160 miles in front of the center, and the fall to have been greatest where the wind was strongest, but not to have extended so far towards SW. In Macao 2.48 inches of rain were measured on the 10th, 6.41 on the 11th and 1.27 on the 12th.

The angle of the wind with the gradient or rather with the straight line between the observer and the center was 32° in the advancing semicircle and 57° in the rear. The mean of all the observa- tions discussed was 44°. This agrees with the result obtained from the typhoon of the 22nd August, but could in this instance not be so accurately determined as in case of that typhoon. The angle being so much smaller in front than in the rear would at first sight seem abnormal, but it should b remembered, that the winds in front were on the whole off-shore winds, and therefore subject t› greater friction than the winds behind the center,.which on the whole had passed over a great expan of ocean and were subject to less friction. The off-shore winds may also have been to some extent influenced by the Canton River.