75
The Barometer is a standard one of the Meteorological Institute with a vernier to read to tenth parts of millimeters, and the thermometer reads to tenth parts of centigrade degrees.
No fire is ever placed in the room in which the instrument is fixed, and the direct sunlight has no access to it.
All barometrical numbers in these tables are corrected to the freezing point (32 degrees Fahrenheit) and the level of the sea. Correction for capacity and capillarity has been made by the placing and division of the scale.
The thermometers were all examined in snow on the 13th December 1870. All numbers of temperature are corrected. The psychrometer hangs on the N. N. W. side of the institution in the open air, but perfectly protected against direct sunlight.
Brightness of the sky.—In these tables we have adopted the old style, that is 0 represents a very cloudy dark sky; and 10 a wholly cloudless atmosphere.
Rainmeter. This instrument stands at 46 meters above the level of the sea on the platform, which is erected on the roof of the School. At the same place the weather-cock with wind-guage is attached. The quantity of rain is measured every 24 hours.
Results.
Direction and force of wind.
The experience and journals of many seamen have long since shewn that, in the China sea, from the island of Formosa, along the China coast up to the Japanese Archipelago, two monsoons of different duration prevail during the year. These are the S.W. monsoon from June till September, and the N.E. monsoon from October till May.
Nagasaki is decidedly situated within the regions of these monsoons, but there is a slight variation in the direction of the north-east monsoon at that place. During June, July and August the S.W. monsoon prevails at Nagasaki perfectly in the same direction as in the China sea; the N.E. monsoon, however, turns more towards the N. and N.N.W., a fact chiefly caused by the geographical
