Public Parks. 



71 



mean temperature of 50.2°. The extremes of heat and cold are more 

 marked in the outskirts, than in the city, where, no doubt, the build- 

 ings have some influence in moderating the temperature ; as, by 

 comparison, I find that in May, June, July, and August, it was colder 

 in the heart of the city, but the remainder of the year it is colder on 

 the outskirts. The only way in which this change of climate can 

 be accounted for is, tliat since 1S36, at least two-thirds of the timber 

 that covered the country on which Chicago now stands, and its 

 vicinity, has been destroyed, and that the region directly north of the 

 city approximates nearer to the conditions that obtained, when the 

 observations were made at Fort Dearborn, and that less timber has 

 been destroyed ther^ than in any other direction.* The following 

 table, compiled mainly from the Army Medical Reports, for i860, 

 will give some idea of the relative temperature of the different 

 localities, as compared with Chicago. Many of the observations 

 extend over a long period, and were made before the settlement of 

 the country had any influence upon the climate of the locality. 



Annual Mean and Eange of Thermometer. 



St. Louis 



Detroit 



Mackinac 



Sault St. Marie . . 



Fort Howard 



Prairie du Chien. 



Kock Island 



Port Ripley 



Fort Snelling 



Council Bluffs... 

 Fort Laramie — 



Toledo* 



Milwaukee t 



Chicago 



Chicago $ 



Near Chicago 1| .... 



Chicago 



Lansing § 



MEAN. KANQE. 



Mean of Thermometer hy Seasons. 



SPRITSrG. SUMMER AUTUMN 'WINTER 



54.15 



45.75 

 36.73 

 37.53 

 43.52 

 4S.6fi 

 50.52 

 39.33 

 45.54 

 49.28 

 46.84 

 48.17 

 43.68 

 44.90 

 46.80 

 47.00 

 48.30 

 43.77 



76.36 

 67.60 

 61.95 

 62.21 

 68.51 

 72.28 

 74.12 

 64.94 

 70.61 

 74.76 

 71.94 

 70.86 

 67.44 

 67.. 33 

 71.38 

 75.00 

 73.66 

 68.98 



55.44 

 48.67 

 44.85 

 43.54 

 46.01 

 48.53 

 51.42 

 42.91 

 45.89 

 51.36 

 50.32 

 51.39 

 48.81 

 48.84 

 54.60 

 48.60 

 52.66 

 48.46 



32.27 

 26.84 

 20.04 

 18.32 

 19.91 

 21.25 

 24.88 

 10.01 

 16.05 

 21.73 

 30.54 

 28.91 

 20.47 

 25.90 

 26.13 

 20.40 

 24.30 

 23.87 



12Yrs. 

 13 " 



24 " 



31,:," 



21 " 



19 " 



11/2" 



6 " 

 35 " 



7 " 



6 " 



7 " 



22 " 

 1833-ia36 

 1866-67-68 

 1868 



1866-67. 



* Dr. Trembly. t I. A. Lapham. % Langgnth. 

 T Eange for three years. 



Brooks. § Kedzie. 



* Horticulturists and florists inform me that there is less danger from frost, and that generally 

 speaking, the products of the garden thrive better north of the city than in any other direction. 



