88 



ILLINOIS ACADEMY OF SCIENCE 



tract 18, when the center of the low occurs over the Gulf 

 coast. The number of observations in each area is sufficient 

 to give a fairly reliable average of the weather conditions in 

 all tracts except 18 and 25. For this reason the averages in 

 these tracts have been checked by a question mark in the ac- 

 companying diagrams. 



The number of observations given in figure 10 also show 

 that the center of the low passes north of Davenport about 



LEGEND 



^^ 12-10 MILES PER UOUR 



^23 10-8 



LZHs-e 



Figure 13. Wind Velocity 



twice as frequently as to the south. It passes east and west of 

 the city with about equal frequency. These results evidently 

 depend upon the location of Davenport with reference to the 

 storm tracks traversed by the cyclones. 



The distribution of the barometric pressures is shown in 

 figure 11. The numbers within the circles give the average 

 pressure in inches for each tract. The heavy concentric lines 

 represent isobars which conform to the pressure values. In 



