20 BIRDS OF ILUNOIS. 



With regard to this snbject we cannot, in the present work, enter 

 into detail, liiit must be content with presenting a few diita by way 

 of illustration of the above remarks. 



In the "Tables and Results of the Precipitation, in Rain and Snow 

 in the United States," collected and published (in 187"2 and 1K81) 

 by the Smithsonian Institution, Professor Charles A. Schott, the 

 compiler, recognizes (pp. 127 — 183 of first edition, 197-203 of second 

 edition), ten geographical areas, each of which is characterized by 

 marked peculiarities in the distribution and quantity of the rainfall. 

 Illinois comes chiefly if not entirely within "Type IV" pf these 

 regions, including the Ohio Valley, which is characterized as follows : 

 "One principal maximum, and one principal minimum; the former 

 early in June, the latter early in February. Range, moderate." 

 This region is to be compared, in the illustration of our subject, 

 with "Type I. Atlantic seacoast from Porllund to ]Vash'ui<iton," which 

 has "Three nearly equal maxima, about the middle of May, .August 

 and December, and one principal minimum about the beginning of 



February;" "the range between the extreme monthly values 



small," and "the August maximum generally the highest." 



These are, however, mere technical differences, only appreciable 

 to, or recognizable by, the meteorologist. 



With the following data* we shall dismiss this subject : — 



I. Comparath-c viean annual temperature and rainfall. 

 Chicago.— hat. 41^52' alt. G60.92 feet. 



Mean annual temperature (8 years) 49"1. 



Total annual rainfall (8 year8( 8r).27 inches. 



Boston.— hat. 42 21', alt. 142.19 feet. 



Mean annual temperature (9 years) 48''4. 



Total annual rainfall (9 years) 50.82 inches. 



Lidianapolis, Ind.— hat. 89^47', alt. 746.58 feet. 



Mean annual temperature (1 year) - • .53"3. 



Total annual rainfall (8 years) 45.22 inches. 



Philadelphia, Pfl.— Lat. :31' r>7, alt. 52.42 feet. 



Mean annual temperature (9 years) 5;V1. 



Total annual rainfaU (8 year8( 42.93 inches. 



•Compiled from the Annual Reports ot the Chief Signal Offlce. C. S. Army, 1871-1880. 



