86 
ILLINOIS ACADEMY OF SCIENCE 
four hours; its probable translational velocity; and the distribu- 
tion of the meteorological elements within the highs and lows. 
The purpose of this paper is to describe some of the results 
obtained from a statistical study of the distribution of the 
weather elements for Davenport, Iowa. The present work is 
based upon a method of study devised by Dr. J. A. Udden and 
described by him in a paper entitled, "On the Cyclonic Distri- 
bution of Rainfall."* 
The plan consists in constructing a hypothetical cyclonic area 
Figure 11. Barometric Pressure 
as shown in Fig. 10. Four concentric circles are drawn whose 
radii measure respectively 100, 400, 700 and 1000 miles in 
length. Eight radii 45 degrees apart and extending from the 
outer to the inner circle delimit 25 tracts within the hypothet- 
ical cyclone. These are numbered from 1 to 25 in the figure. 
•Augustana Library Publications, No. 4, Denkman Memorial Library, Rock 
Island, 111. 
