12 



ANTIQUITIES OF WISCONSIN. 



The relative iDOsition and extent of the earthworks in the vicinity of Milwaukee, 

 will appear on reference to the map, Plate III. They extend from Kinnickinnic 

 Creek, near the place known as the Indian Fields, to a point six miles above the 

 city. It Avill be observed that they occupy the high grounds along the margin of 

 the river and streams, but not on the immediate shore of the lake. Although the 

 mound-builders often occupied the margin of the smaller lakes in the interior, they 

 seldom or never selected the immediate shore of Lake Michigan for the site of 

 their works. 



representations of the Massasauga rattle-snake. My attention was first called to them by Mr. M. 

 Spears, who detected them. They vary from a few inches to two feet in height, above the otherwise 

 uniformly level surface of the marshy ground ; and in length they vary from ten or fifteen to one 

 hundred and forty feet. Many of them are obtuse at one end, and tapering and acute at the other," 

 as if intended to represent the head and tail of a snake ; others are acute at both extremities. (See 

 rig. 4.) The accompanying figures show their appearance and relative situation. Some are so 



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Serpent-form ridges, Brookfieltl. 



arranged that, were they larger and differently situated, we might suppose them portions of a fort, with 

 a guarded entrance. They are composed of the same black mucky earth that constitutes the surface 

 soil of the marsh. They have all the same general direction, being parallel, or nearly so, with that 

 of the marsh. There are great numbers of these ridges, not less, perhaps, than one hundred on this 

 marsh. 



To understand how these ridges were probably formed, we must take into account the soft nature of 

 the surface soil ; and the fact that, except in the driest jDortion of the year, it is completely saturated 

 or covered with water. The ice formed on the surface in winter must therefore include a considerable 

 portion of the soil. During very cold weather, this covering of ice contracts, leaving in the middle of 

 the marsh numerous irregular cracks, probably assuming the arrangement and directions of these ridges. 

 As the temperature moderates, the ice expands, closing up the cracks, but moving towards them a 

 portion of the soil, and leaving a slight elevation. The next winter, the same thing is repeated ; but 

 the ice being thinner on these slight ridges, it would natura'ly separate where they occur: and thus the 

 same ridges are enlarged from year to year, until they assume the size and shape now so much resembling 

 serpents. We afterwards saw similar ridges in several other marshes. 



