30 RURAL MICHIGAN 



able timber. A similar performance was observed 

 over Houghton a few miles to the northeast on July 

 31, 1913, but at most places did not descend to the 

 point of destructive contact with the earth. That 

 these were not the first such visitations to the Upper 

 Peninsula is evident from the large tracts of "down" 

 timber observed by Pumpelly and other early ex- 

 plorers of the interior of the region. In the Lower 

 Peninsula, the record of tornadoes associates them 

 with the south central counties, where a few very 

 violent storms have occurred, such as that in Oak- 

 land County, May 25, 189G; at Owosso, Nov. 11, 

 1911; near Charlotte, 1915; in Jackson, Calhoun 

 and Ingham counties, 1917; between Ann Arbor and 

 Dexter, 1917; and a series of tornadoes at several 

 points simultaneously, including Fenton and St. 

 Johns, March 28, 1920.^ Normally, however, winds 

 of high velocity are unusual in Michigan. The 

 maximum average hourly velocity is twelve and 

 one-half miles in March and April, and the minimum 

 velocity nine miles an hour in August and Sep- 

 tember.^ Pare, too, are those intensely hot dry 

 winds that blight growing crops and parch the earth 

 with their torrid breath. Yet these also do occur, 

 even if seldom, entering the State from its unpro- 

 tected southwestern angle in both peninsulas, or 

 arising from areas of superheated air within the 

 State itself. Then, if the wind is off shore, the 

 presence of one of the Great Lakes is of no avail, 



' Seeley, 22-23. 



' Schneider in "Surface Geology of Michigan," 17, 38, 



