(5S IOWA ACADEMY OF SCIENCES 



Mr. J. W. Merrill, editor of the Mediapolis New Em, vouches 

 for this story: A large circular windmill tank, with nearly 

 straight sides, stood removed from bui dings upon level ground. 

 It had never been used as a tank and was dry Monday night. 

 It had a semi-circular cover, which was open, exposing one- 

 half the tank to the rain. The water ia the tank measured 

 twelve inches in depth on Tuesday morning. We will grant 

 that some of the water in the tank ran in from the half which 

 was covered. Yet. had it all run in — and it could not — there 

 would have been a rainfall of twelve inches. If the tank had 

 been perfectly level, would more than one-half the water which 

 fell on the cover have entered the tank? 



In Dry Branch valley, below Latty, six miles south, lives a 

 member of the county drainage board, a man whose judgment 

 can be relied upon. He states that on Monday night an empty, 

 straight-sided tin can which was used for mixing spray fluids 

 for fruit trees, was left in open ground. The can was about 

 fifteen inches in diameter and sixteen inches high. At 5 o'clock 

 the can was full and running over. North of West Burlington 

 lives a truck gardener, who left standing in the garden several 

 sprinkling pots, whose open tops are half covered with tin in 

 the usual manner. These ought to have shed one-half the 

 water, yet daylight found them all with eight or nine inches of 

 rainwater in them. 



Other less reliable cases have come to my notice, where the 

 hole of a barrel becomes the outlet for overflow, etc. The 

 instances given suflice to show the character of the informa- 

 tion which leads me to firmly believe that over an area of fifty 

 square miles at least sixteen inches of water fell in three 

 hours. 



The instances of incredibly rapid rise in streams, even when 

 already in the flood plains, seem to corroborate the estimates 

 given above, while the records at the Mississippi bridge at 6 

 p. M., August 16th, show a stage of four feet five inches, a rise 

 of three feet two inches. When we remember that local rain 

 seldom affects the stage of water noticeably, and take into 

 account the limited area of the storm, we must readily see that 

 something extraordinary must have happened. The rain 

 extended some distance up the river, it is true, Clinton report- 

 ing 8.01, Davenport 2.20. 



The erosion was well in keeping with the figures given for 

 rainfall. Little idea can be conveyed of ihe force of the water. 



