PHYSICAL AyD CLIMATIC SETTING 19 



much of the west Michigan coast-line enjoys, the 

 predominantly fruit-producing section of the State. 

 Indeed, many varieties of fruit do very well along 

 the "sleak"' Lake Superior shore, where defects of 

 soil rather than of climate hmit the productivity. 

 The manner in which this influence of the Great 

 Lakes is applied is directly related to the normal 

 westerly direction of the winds. Grand Haven 

 on the western shore of the Lower Peninsula has a 

 temperature in winter averaging higher than that 

 of Milwaukee on the opposite shore of Lake Mich- 

 igan, while its summer temperature runs several 

 points lower. Its coldest days in winter and its 

 warmest days in summer are never so extreme in 

 their range.^ This explains the presence of a "fruit- 

 belt" in western IMiehigan and its absence in the 

 eastern or Lake Huron-Lake Erie coast-line, al- 

 though these lakes are normally of about the same 

 temperature. The trend of the northern peninsula 

 is west to east, so this influence of winds and lakes 

 works out differently. ]\Iarquette's hottest summer 

 days occur when the wind is southwesterly, deriving 

 its torridity thus from the superheated land sur- 

 face over which it is moving. Yet a shift to the 

 northwest will, in a few minutes, cause one to seek 

 protection from the frigidity of the outer air.^ Such 

 hot blasts as occasionally afflict dwellers by this great 



'Seeley: "The Climate of Michigan and its Relation to 

 Agriculture." 



^ July 14, 1920, in ten minutes the U. S. Weather Bureau 

 thermometer fell 27 degrees. 



