1892.] NATURAL SCIENCES OF PHILADELPHIA. 473 



emphasis which was at first placed upon the terminal moraine as 

 marking the southern limit of the area occupied by ice during 

 glacial times. Into this error Professor Lewis and I fell at first 

 equally with others, though I believe my experience led me to free 

 nayself from it sooner than most others. The fact is that in Eastern 

 Pennsylvania, and in portions, certainly, of New Jersey, the 

 "fringe" does extend a considerable distance beyond the terminal 

 moraine. In the Susquehanna, the southern limit of the ice was 

 several miles below Berwick. While the Delaware Valley was 

 occupied by a lobe of the glacier, which extended in the axis of the 

 valley to the Musconetcong range, five or six miles southeast of 

 Easton, and about fifteen miles south of Belvidere, which has here- 

 tofore stood as the limit. The supposed evidences of a farther 

 extension of the ice southward are readily explained, in a manner 

 which I will presently detail. The evidence upon which these con- 

 elusions are based is as follows : 



1st, as to the Susquehanna terraces : I began my investigations at 

 Harrisburg. Here I had the advantage of the minute local knowl- 

 edge of Dr. Harvey B. Bashore, of West Fairview, who had been 

 in correspondence with me concerning the terraces of the vicinity 

 for more than two years. The terraces are for the most part situa- 

 ted in the city of Harrisburg, and Dr. Bashore has scoured the 

 country far and near, and speaks with no ordinary authority upon 

 the subject. I visited the principal points with him, and am pre- 

 pared to endorse his concise statement of the case which he has 

 written out for me at my request. 



" The first terrace at Harrisburg is 28 feet above low water (290 

 A. T.) upon which Front street is mainly built, and is composed of 

 clay suitable for brick-making, and contains many boulders of large 

 size (4 to 5 feet in diameter), composed of conglomerate and sand- 

 stone from the mountain, through which the river has cut a gap a 

 few miles above. This deposit is distinctly marked on both sides of 

 the river. 



" The second terrace is 46 feet above the river, but it is not plainly 

 marked. Third street, however, is in a great measure built upon it. 

 This bed is composed of gravel, which has in it some granite and 

 gneiss, and contains large and small boulders all rounded, and is 

 capped by two to three feet of fine loam. 



"The third terrace is 90 feet above the river, and forms the plane 

 of Sixth street and part of Fifth. This deposit, which gives a good 

 perpendicular exposure of 15 feet, is composed of fine gravel, some 

 portions of which are granite and gneiss. A few boulders appear in 

 it, from two to three feet in diameter. All are well rounded, and 



