294 ATMOSPHERE IN RELATION TO HUMAN LIFE AND HEALTH. 



classes to be compared, respectively good and deficient in ventila- 

 tion or space, the results as regards health, vigor, intemperance, and 

 efficiency. 



WIND FORCE AND HEALTH IN A LARGE TOWN. 



In an inquiry made quite recently by the present writer, but hitherto 

 unpublished, concerning the relation between the health of London in 

 winter and the force of the wind, the conclusion was arrived at that on 

 the whole, the mortality is greater in calm than in windy weather, and 

 that there is much less variation in the death rate during the preva- 

 lence of strong winds than during the prevalence of gentle winds and 

 calms. The period examined was from November, 1872, to December, 

 1893. In January, 1890, and in the first quarter of 1892, influenza 

 greatly raised the mortality above the normal, but since this is one of 

 the zymotic diseases, of which the prevalence is increased by calm 

 weather, the figures for these periods have not been omitted. The 

 months of October, November, and December, in 1879 and in 1839, 

 were the least windy periods recorded, and each was followed by a high 

 death rate. Several calm periods coincide with great cold and fog, and 

 it is these in combination which have the worst effect upon health in a 

 smoky town. 



Further investigation is required to ascertain which diseases are 

 most apt to spread in calm weather, and the relation of particular 

 winds to particular diseases. 



The following table represents roughly and approximately the rates 

 oT mortality in the periods mentioned: 



Minima, hourly horizontal movement less than 11 miles. 



Period. 



December, 1873 (22 calm hours, cold and fog) 



February, 1874 (33 hours calm) 



November. 1 874 (34 calm hours) 



February, 1875 (no calms) 



October and November, 1876 (no calms) 



February, 1878 



December, 1878 (36 calm hours) 



October, November, and December, 1879 (131 calm hours) 



January, 1880 



November and December, 1885 



February, 1886 



.January, 1887 



December, 1888 



January, 1889 



November and December, 1889 



December, 1890 



Quarter ending April 2, 1892 



October, November, and December, 1892 



Total 



28.2 



24.6 



27.2 



25.7 



21.4 



25.4 



28.1 



26.6 



31.2 



20.64 



24.9 



21.8 



10.8 



20. 3 



19. 48 



24.7 



28.2 



18.5 



23.1 



23.1 

 31.4 

 23.2 

 22.4 

 24.3 

 26.8 

 31.2 

 31.7 

 22.5 

 26.9 

 19.3 

 23.2 

 18.2 

 28.1 

 28.5 



24.42 



