Dress, with reference to heat : being a lecture written for, and published by the Australian Health Society / by Walter Balls-Headley.

  • Balls-Headley, Walter.
Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: Dress, with reference to heat : being a lecture written for, and published by the Australian Health Society / by Walter Balls-Headley. 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.

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    the calico ; and even after three hours of cooling, it was 3 deg. in excess. From such and many other experiments it is evident, that -wool is a much better non-conductor than calico, and that, from wool not being liable to be saturated, it is far less likely to cliill the surface. It therefore becomes desirable, that woollen materials should always be worn next the skin in a climate, where the temperature is subject to ra])id and frequent changes ; or where the body is, by the nature of the em[)loyment or otherwise, so exposed. A modification of a material composed entirely of wool, is merino, which is made of a mixture of cotton and wool. Soakag e of the cotton fibre is much less liable to occur when so mixed with wool, than when it is all cotton ; for the effect of juxta-posit ion is not so decided. Merino being made in various thicknesses is particularly suitable to those, whose habits of life do not induce so muchmoisture of skin; or who cannot bear the sensation of wool touching and tickling them ; or who, wearing other clothes, do not find it necessary to work only in their shirts. Macintosh and other waterproof materials, being impermeable to- moisture, prevent evaporation of the moisture of the skin; which, being thus retained, collects in the clothes ; and, on removal of the coat, is evaporated at loss of great heat to the body, when it can perhaps ill sj^are it. The colour of the external garment has a strong bearing upon the effect produced by the sun. Thus in the sun at a temperature of 8.3 degrees, while in a quarter of an hour the heat under white flannel was 87 degrees; under red it was 92 degi-ees? and under black 97 degrees; that is, 10 degrees hotter than under white flannel. Similarly with calico; an unglazed surface of black calico was 9 degrees hotter than that of glazed white calico* Again an unglazed material, as unbleached calico, absorbs much more heat than a glazed ; so that in an experiment I found the dif- ference to be 7 degrees : and on exposure to the sun of the same piece of black calico, of which in the one case the glazed side was outside, and in the other the unglazed, the former registered only 84i degrees, in comparison with 89 degrees of the latter. On.