Report of the Committee for Scientific Inquiries in relation to the cholera-epidemic of 1854.

  • Great Britain. General Board of Health. Medical Council.
Date:
1855
Catalogue details

Licence: Public Domain Mark

Credit: Report of the Committee for Scientific Inquiries in relation to the cholera-epidemic of 1854. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    slightly in defect) every month of the year showed an excess above the average of diurnal range ; March, April, and especially September being most remarkable in this respect; and the total result of this is, that, while for the thirteen years ending 1853 the mean yearly diurnal range was 14° 6, the range for 1854 was 18°' 1, being 3^° above the average. But in comparing the extreme readings of the Greenwich and other outlying stations with those of London proper, Mr. Glaisher discovers the startling fact, that his central stations undergo a much less daily range of temperature; that, because of the dense veil which overhangs them, they, during day-time, cannot get equal heat from the sun, nor during night-time can equally cool themselves into space. Such excesses of night-temperature have amounted in the weekly mean to 7°, 8°, 9°, and 10°; and as between particular stations, to 15° and 20°; a period marked by this extreme difference having extended but for twelve nights' interval, from the 26th of August to the 4th of September. Remembering that, amid the districts which most of all present this high night-temperature, there is spread the vast evaporating surface of the Thames,—a river which (so far at least as London is a drained city) represents the main sewer of our metropolis,—remembering, that from its putrescent banks and waters there arise vapour and miasm in proportion to that level of temperature, we must recognise the full right with which Mr. Glaisher insists upon this feature of our London climate. Almost unin- terruptedly, too, the heat of the water is some degrees greater than that of the superincumbent air; for 28 con- secutive nights, ending September 12th, this excess aver- aged IG^'S; and there was another fortnight, beginning a few days later, during v/hich it averaged 16° 5. At such periods we may (as Mr. Glaisher expresses it) infer the water to have been simmering, and the whole area of the Thames to have been giving off incessant and vast volumes of vapour, which, unsustained by the colder air, hovered over the city, thickened its atmosphere, occa- sioned the frequent prevalence of fog and mist, and explained the less daily range of temperature in stations overshadowed by its influence. (iv.) The vaporosity of the atmosphere is estimated by a twofold standard; first, what quantity of vapour is actually hoi den in the air—how many grains per cubic foot—and what share does its weight contribute to the total of baro-