IOWA ACADEMY OF SCIE^X'ES. 67 



Out of these he fashioued his spear aud arrow points, knives and drills. 



In the beds of those ancient lakes, the geologist has described, the arch- 

 u'ologist looks for the tools and weapons of prehistoric man. Near the 

 close of the great Ice Age in this latitude, especially in Iowa, numerous 

 lakes were formed along the courses of the rivers by occasional barriers of 

 ice across the valleys of the streams. 



The city of Muscatine stands on the bed of one of these lakes. At that 

 time the surface of this lake stood nearly at the top of our highest hills, 

 perhaps one hundred and fifty feet above high water in the great river at 

 our feet. 



The tine grained yellowish brown material, so conspicuous at our brick- 

 yards and in all streets where cuts have been made, was deposited in this 

 lake. It covers the Drift, or at an}' rate the coarser materials of the Drift, 

 and lies over our hills like a great mantle. In places it is from fortj' to 

 fifty feet thick. 



The geologist calls it Loess. It is the last in the series of marked physio- 

 graphical ciianges that have occurred in this region. The border or shore- 

 line of this Loess lake is quite easily found. From this Loess have been 

 taken several species of land and fresh-water shells, the remains of two 

 American reindeer, fragments of wood, the antler of some species of deer, 

 etc. Long ago I was led to believe we ought to obtain evidence that men 

 were here befoi*e this lake had disappeared. Ou Eighth street, near St. 

 Matthias church, Mr. Chas. Freeman was for many years engaged in chang- 

 ing a fine hill of this Loess into brick. I have before me a rather rudely 

 formed spear point of pinkish chert. This, Mr. Freeman says, he took from 

 the Loess at this place at a point about twelve feet from the surface. In 

 answer to my questions he said it could not have possibly dropped from the 

 top, for he was digging under the bank for the purpose of caving it down 

 when the spear point was struck, and he was specially interested in the 

 impress or matrix where it lay. Several of the deeper depressions on this 

 implement are still filled with the characteristic Loess. About the same 

 time in the same bank as the Loess was caved off, Mr. Freeman noticed a 

 stone, as he supposed, projecting from the vertical wall. As such things 

 were rare in this compact homogeneous Loess, he examined it and found it 

 to be an arrow point projecting from the undisturbed earth, at least twenty- 

 live feet below the surface. At a brickyard about two blocks to the north of 

 this, as Mr. Freeman was moulding brick, he took from the clay a well- 

 formed arrow point. This was covered with a blue clay quite different from 

 tiie usual Loess. Inasmuch as this arrow point had passed through the bed 

 where the clay is mixed it seemed as if the story it told was not very clear. 

 At a point in this bank a bed of fine blue clay was uncovered. The top of 

 this blue clay was over eight feet from the surface. On examination of the 

 bank and^inquiry into the circumstances 1 believe, with Mr. Freeman, that 

 the arrow point must have come from the blue clay. About one mile from 

 where itcempties into the Mississippi river. Mad Creek has cut away the 

 l^oint of a hill, the top of which is Loess. This cut forms a bank almost 

 perpendicular, probably forty feet high. About ten feet from the top is a 

 bed of gravel perhaps one foot thick. In this gravel bed Mr. Joe Freeman, 

 a third jear student in our High school, found a considerable fragment of 

 the tooth of an elephant. I examined this gravel bed and found in it 



