ENGELMANN — RAIN AND SNOW TABLES. 77 



Fall of Main (including melted Snoic) in St. Louis, from 

 1839 to 1861. 



By George Engeljiann, M.D. 



The foregoing Tables are the result of my observations 

 continued through a series of 23 years. They exhibit in 

 English inches the monthly quantities of atmospheric water, 

 which is precipitated in the form of Rain or Snow, and their 

 sums and averages. 



My rain gage is placed on the roof of my house, but, unfor- 

 tunately, not entirely free from the influences of currents of 

 winds produced by neighboring chimneys and houses; the 

 results, however, are probably not far from the actual quan- 

 tities. 



The first twelve columns of the first table give the monthly 

 and the thirteenth the annual quantities; the next four exhibit 

 the quantities of the four seasons, taking December, January, 

 and February, for winter; March, April, and May, for spring, 

 etc. The last two columns comprise the rain of the fall and 

 winter months, and that of the spring and summer months. 



The quantity of rain in the different years varies, as the 

 table shows, between near 30 and near 69 inches, the aver- 

 age being nearly 45 inches. 



The monthly amount of rain increases from January, when 

 on an average it is less than 2 inches, to June, when it 

 reaches over 6 inches ; and then varies through the remain- 

 ing six months of the year between 3 and 4 inches, being 

 least in Sejitember. 



The quantity of rain is smallest in December, January, 

 February, and September, reaching only 3 inches or less; unci 

 greatest in May and June, over 5 inches. The quantity in 

 the three summer months is greater than in any other season ; 

 the three spring months come near to it. The average 

 amount of rain in the spring and summer months, over 27 

 inches, is about 62 per cent, of the annual fall; while only 

 17 inches, or 38 per cent., falls to the share of the other six 

 months of the year. The last columns, however, of the table 

 show that this is by no means so in each single year; we 

 find 3 years among the 23, when the fall and winter rains 

 predominated over the spring and summer rains. 



The diagram, Plate 4, exhibits at one glance all these re- 

 sults. The middle line connects the mean quantities of rain 

 for every month; the upper curve indicates the maxima, and 

 the lower one the minima, of the monthly rains observed in 

 the last 23 years. It will be seen that the curve of the mean 

 quantities gradually rises from January to June, and then 

 falls rather abruptly to July, remains almost on the same 



