The preferable climate for phthisis, or, The comparative importance of different climatic attributes in the arrest of chronic pulmonary diseases / by Charles Denison.

Charles Denison

Date:: [1887]

Credit: The preferable climate for phthisis, or, The comparative importance of different climatic attributes in the arrest of chronic pulmonary diseases / by Charles Denison. 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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$/ To illustrate this distribution of cloudiness, the writer has drawn the lines representing all these records of the United States Signal Service Bureau up to January, 1886. (See accompanying chart.) The variations for cloudiness range from above sixty per cent, of the time, over the interior lake region, down to less than thirty per cent, in the southwestern portion (New Mexico and Arizona). Taking so broad a field into calculation, a striking harmony is noted between cloudless- ness or sunshine and the other favorable attributes. They all go together. A preponderance of sunshine should be mentioned as favoring the possibility of much- to-be-desired out-door life, and also of the camping-out idea in summer time. Many excellent illustrations resulting therefrom could be cited if time permitted. V. VARIABILITY VS. EQUABILITY. How uniformly variability goes with dryness and equability with moisture can be illus- trated by the daily and monthly ranges of temperature at places which represent dry and moist climates. Chosen without reference to this particular evidence, twenty-five dry and twenty-five moist prominent stations and health resorts in the United States give the following means :— s TABLE IV. Means of Daily * - Ranges. First—Extreme dryness 36-51° Second—Moderate dryness. 20.63° Third—Moderate moisture 17.09° Fourth—Extreme moisture 13.61° Means of Monthly Ranges. 53-65° 49-38° 45-48° 41-55° Again, taking the fifteen most and the fifteen least variable signal stations in the United States for 1883 (out of the 136 stations), we have the following daily ranges averaged by seasons and for the year :— TABLE V. Fifteen Stations. Spring. Summer. Autumn. Winter. Year. Most variable 30.70 29.1° 28.4° 28.5° 28.7° Least variable 12.10 12.9° 10.8° 12° n.90 The first are extremely dry, and the second fifteen decidedly moist localities.* Seasonal ranges of temperature likewise show the inseparability of equability from atmospheric moisture and of variability from dryness. Compare the winter and summer tem- perature lines on seasonal charts. The sea is the great equalizing influence, and the colder land in winter turns these isotherms to the south for a considerable distance in the United States, viz., about parallel with the Pacific Coast. In the summer, however, when they leave the ocean, these lines are turned nearly as much to the north as the winter ones are to the south. The further we get away from humid influences the greater is the varia- bility of temperature. It is not claimed that extreme variability should always be sought for, nor that of two places with all other advantages the same the more variable one is the better. On the con- trary, the less variable would certainly be preferred in cold weather. It is claimed, however, that variability is quite a uniform constituent of dry, high climates, and that as the dryness predominates, the marked variability is less felt, and is less, if at all, objectionable. On the other hand, marked atmospheric equability, wherever found, is prima facie evidence of excessive humidity. The worst that can be said against combining variability with the favorable attributes of climate for phthisis is that its defense is necessary, because it is a sine qua non of the prefer- able combination. Very well; but there would be no excuse for advocating a false theory of climate, even if this one element were unfavorable. There is a prevalent exaggeration of the effect of temperature changes. The change gets the blame which rightly belongs to the * The highest average variability for the winter of that year was La Mesilla, N. M. (34.6°), and the lowest both San Francisco, Cal., and Key West, Fla. (8.8°). \$