Abstract
LONDON. Royal Meteorological Society, Jannamy 16.-Dr. W. Marcet, F.R.S., President, in the chair.—The Report of the Conucil showed that a large amount of work had been done during the past year, and that considerable progress had been made in the investigation of one of the most interesting and hitherto neglected branches of meteorology, viz. thunderstorms. Forty-nine new Fellows were elected last yeam, the total number on the books now being 525.—After the Report had been adopted, the President delivered an address on “Fogs,” which he illustrated by a number of interesting lantern slides. Fogs and clouds are one and the same thing. A cloud is a fog when entered into, and a fog seen from a distance, suspended in the air, becomes a cloud. After describing the various kinds of fog—e.g. river, sea, Newfoundland, radiation, town, &c., fogs— Dr. Marcet referred to London fogs. Dr. Tyndall has accounted for them by assuming each particle of condensed vapour to be covered by coal smoke. These fogs usually accompany a high barometer, and are frequently dry in their character. It is a well-known fact that cold air on the tops of hills, being heavier than the air below, slides down the slopes, so that the lower parts of the hill-sides are actually colder than the plains at some distance from the hills. Now, London, in the Thames Valley, is surrounded by hills—to the north, Highgate, Hampstead, and Harrow; in a westerly direction, Putney and Wimbledon; and in a more southerly direction, Clapham and Sydenham. The air is colder on these hills than in London with its millions of inhabitants, its coal-fires and factories, hence it is heavier, and will have a great tendency to slide down the hills towards the town and the river. Should the air in town be on the point of saturation, and the cold air from above saturated with vapour, it is obvious that the increased cold from above will produce a precipitation of moisture, and it will come to pass that a fog is produced. If the hill-tops be not only colder than the air below, but enveloped in a fog, it stands to reason that the fog below will be all the denser, and especially in the neighbourhood of water, such as the River Thames and the ornamental waters in the parks.—The following gentlemen were elected the officers and Council for the ensuing year:—President: Dr. Wm. Marcet, F.R.S. Vice Presidents: Francis Campbell Bayard, Henry Francis Blanford, F.R.S.,William Ellis, Richard Inwards. Treasurer: Henry Perigal. Trustees: Hon. Francis Albert Rollo Russell, Stephen William Silver. Secretaries: George James Symons, F.R.S., Dr. John William Tripe. Foreign Secretary: Robert Henry Scott, F.R.S. Council: Edmund Douglas Archibald, William Morris Beaufort, Arthur Brewin, George Chatterton, William Henry Dines, Frederic Bernard Edmonds, Charles Harding. Baldwin Latham, Capt. John Pearse Maclear, R.N., Edward Mawley, Henry Southall, Dr. Charles Theodore Williams.
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Societies and Academis . Nature 39, 310–312 (1889). https://doi.org/10.1038/039310c0
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DOI: https://doi.org/10.1038/039310c0