1876.] 55 [Wright. 



South from Windsor to the Massachusetts line, distinct remnants 

 are found every five to ten miles. Mr. Upham thinks it originally- 

 extended all the way south from Lyme, but does not think it was 

 ever continuous above Lyme. A most noticeable point about this 

 Connecticut Valley kame, Mr. Upham writes, is that it has no 

 branches or parallel ridges, but extends in a very direct course in a 

 single ridge along the bottom of the trough-like valley. It has been 

 cut through by the now devious river seven or eight times. It is of 

 sand and gravel, the latter predominating, in which the pebbles are 

 mostly less than one foot in diameter, but sometimes one and one- 

 half to two feet for the largest. No boulders, nor anything resem- 

 bling " till," is seen in, or on the surface of the kame, except at one 

 point, 225 feet above the river, 600 feet above the sea, where two five- 

 foot boulders were found on its top. 



Formations of a similar nature, under the name of " horsebacks," 

 have been described by Professor C. H. Hitchcock, in various places 

 in Maine. 1 Some of these are said to be forty miles long. Professor 

 Agassiz's observations upon these phenomena in Maine, may be 

 found in the Atlantic Monthly for June, 1864, and February and 

 March, 1867. Mr. James Geikie's description of the " kames " in 

 Scotland, 2 and the "asar" in Sweden, 3 applies in the main to the 

 phenomena we are considering. 



A year ago, in a paper read before the Essex Institute, 4 in Salem, 

 and when my observations had only taken in the series passing 

 through Andover, I declined to theorize much until further facts had 

 been gathered, but I stated provisionally what had been my work- 

 ing hypothesis, viz., that I was following up what might prove the 

 remnants of a medial moraine in that portion of the continental gla- 

 cier which took its local direction from the Merrimack Valley. 

 The general direction corresponded with that of the scratches on the 

 rocks, and the line when projected coincided nearly with the axis of 

 the Merrimack Valley north of Manchester; leading up to the White 

 and Franconia Mountains. Mr. Upham and Prof. C. H. Hitchcock 

 have since directed my attention to the probable action of superficial 

 currents of water during the progress of the melting of the glacier. 



i See Maine Agricultural Reports for 1861 and 1862. 



2 See The Great Ice Age, 2d Ed., Chapter xxi, pp. 239 ff. 



3 Ibid., pp. 408 ff. 



« See Bulletin of Essex Institute, Vol. VII, p. 165-168. 



