Hygiene, or, Health as depending upon the conditions of the atmosphere, foods and drinks, motion and rest, sleep and wakefulness, secretions, excretions, and retentions, mental emotions, clothing, bathing, &c. / by James H. Pickford.

Pickford, James H.

Date:: 1858

Credit: Hygiene, or, Health as depending upon the conditions of the atmosphere, foods and drinks, motion and rest, sleep and wakefulness, secretions, excretions, and retentions, mental emotions, clothing, bathing, &c. / by James H. Pickford. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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$78. The thermometer in Captain Parry's ship at Melville Island was often observed as low as — 50°; and, at a distance from the ship, even as low as 55° below zero. 79. Isothermal lines, or lines of equal temperature.—Hum- boldt has shewn that the earth is encircled by many lines, each of different temperatures, but that the temperature of each line is identical throughout. To these lines the name of Isothermal has been applied. These lines for the most part do not run parallel to each other, but approximate to and diverge from each other in a peculiar and capricious manner, their course being especially influenced by the relations of extent and con- figuration between the opaque continental and the fluid oceanic masses. 80. The Isotherm of 32°, commencing at the Great Slave Lake in North America, 61° 30', pursues an eastward course, crosses the lower part of Hudson's Bay, 52° \5', passes about four degrees south of Nain, on the coast of Labrador, 52° 20', ascends to one degree north of Umea in Sweden, 66°, and is next found at North Cape in Norway, 71° 10', whence it makes an abrupt descent, and attains its lowest limit in the eastern part of Siberia, beyond which its course has not been traced. 81. The Isotherms within the torrid zones run nearly pa- rallel to the equator and to each other. 82. Mean temperature.—By mean temperature is understood that temperature which is equidistant from the extremes. That of the day is found by adding together the results of all the observations, and by dividing the sum by the number of ob- servations. In the same manner are obtained the mean tem- peratures of the week, month, season, and year. 83. In mid-Europe, between the parallels of 38° and 71°, the temperature increases in a constant proportion with lessen- ing latitudes, and diminishes in the same proportion with 78. Journal of a Voyage for the Discovery of a North West Passage, ] 821, p. 145. 79. Kosmos, vol. i. p, 345. 83. Ibid. p. 359.$