Ocean rainfall : with charts and tables, 1864-1875 / by W.G. Black.

  • Black, William George, 1857-1932.
Date:
[1878]
Catalogue details

Licence: Public Domain Mark

Credit: Ocean rainfall : with charts and tables, 1864-1875 / by W.G. Black. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    9/28
    OCEAN 11A INF 1864-1875. Read before the Royal Meteorological Society, Lone with Charts. iiese remarks on Rainfall at Sea have been deduced from Sets of Observations taken by Rain Gauges on board several vessels of the Royal Navy and Mercantile Marine, within the period of about five years, on both long and short voyages in various seas. The results were tabulated into sections, belonging to the Northern Hemisphere and to the Southern Hemisphere, and both again were divided into columns for each month of the year and summed up into total amounts of Rain, Wet Days, Rate of Rainfall per Wet Day and per Total Days, and also per Degree and per 1000 Nautical Miles. Diagrams have also been constructed showing the curves of rainfall and wet days for the year, and the rain belts or regions in a chart of the world where rain is more prevalent than in other intervening spaces of latitude. But these are offered for consideration merely as preliminary sketches of what may in future be made out, and are only applicable for a temporary purpose to the present observations. In the Northern Hemisphere the total rainfall came to 94' 16 inches, total wet days to 169, total dry days to 501. Rates per wet day of rain- fall, 566 inch. Total wet and dry days, 670. Rate per total days, T41 inch. Rate per annum, 51‘29 inches. Wet days per annum, 92; including observations at Foochow. In the Southern Hemisphere the total rainfall came to 94 70 inches, the total wet days to 253, and the total dry days to 918. Rate per wet day of rainfall, '330 inch. The total wet and dry days were 1171, and the rate per total days of rainfall was T10 inch. Rate of rain per annum, 29'43 inches. Wet days per annum, 80; including observations at Fiji Islands. These figures show that there was heavier rainfall in the Northern Hemisphere than in the Southern Hemisphere, but fewer days on which it fell; that the rate per wet day is greater also in the Northern Hemi- sphere than in the Southern Hemisphere, as is also the rate per annum ; and that there were more wet days in the Southern Hemisphere than in the Northern Hemisphere at sea, showing the greater preponderance of drizzly weather in the Southern Hemisphere, and the absence of the equatorial rain belt. The month of September (North Autumn) had the heaviest rainfall (26'05 inches) and the greatest number of wet days (33), in the Northern Hemisphere.