54 Public Parks. 



WINDS — Their Influence on Health. 



Winds are the result of changes of temperature and the pre- 

 cipitation of moisture, acting as changes of density, and as the 

 movements of bodies would act to produce currents and movements 

 in a mass of vv^ater.* This is the strictly meteorological definition, 

 but in a sanitary point of view, there are none of the atmospheric 

 phenomena that exercise a greater influence for good or evil. The 

 free movement of air in summer, in certain localities, is beneficial in 

 dissipating noxious emanations, and purifying the atmosphere, while 

 in the same locality, in the cold season, it abstracts heat, depending, 

 of course, on its velocity and humidity, and thus acting injuriously 

 upon life. The seeds of disease are frequently wafted by winds 

 over unhealthy localities, and thus causing those who live quite 

 remote from the exciting cause to suffer. Fevers and acute pulmo- 

 nary and inflammatory diseases do not usually manifest themselves 

 under the influence of the same wind, although fever and certain 

 other diseases may occur in connection with any currents which 

 waft the air from the neighboring surfaces, where the elaboration of 

 the morbific cause is going on. 



NORTH WIND. 



The north wind is less frequent than any other. It generally 

 exercises a beneficial influence, and in winter is the mildest, with the 

 exception of the south-east and east, owing to the lake and the trees 

 found north of the city. In summer it is cool and I'efreshing. This 

 wind, like all others, is influenced by locality in its eflects upon 

 health, as in New Orleans, in summer, it always causes sickness. 



NORTH-EAST WIND. 



The north-east is the most common wind in spring and summer. 

 In the months of March, April, and May, it is a cold, moist wind, 

 and continues so until the temperature of the earth is higher than 

 that of the lake, when it becomes cool and pleasant, remaining so 

 until November, or until the temperature of the earth becomes lower 

 than that of the lake. This wind increases pulmonary, rheumatic 

 and inflammatory diseases in spring, and is the main reason why 

 that season of the year is so long-continued and unpleasant ; but 

 during extreme heat and cold it is beneficial. The north-east wind 

 blows malarial fever into portions of Rome. In Batavia this wind 



* Blodgett's Clitiiatology. 



