174 D. W. JOHNSON AND W G. REED, JR. 



1846 differs in minor points from the more recent charts of the same 

 area, and a comparison of the two might be expected to show changes 

 in the shorehne since 1846. Indeed, such a comparison has been 

 made in connection with a study of chff retreat at Allerton Great 

 Hill and an estimated retreat of about two feet a year has been inferred 

 on the basis of the comparison. A careful study of the two charts in 

 the light of the geological features of the region makes clear the fact 

 that one or both of them are too inaccurate to warrant any conclusions 

 as to changes in shoreline based on such evidence. For example, 

 it appears from the charts that the shoreline along the southeastern 

 corner of iVllerton Great Hill is farther east today than it was in 1846. 

 Now the shoreline at this point is formed by the cliffed face of the 

 hill, and since this hill is a drumlin which could not have been built 

 forward since the glacial epoch, the charts are manifestly not suffi- 

 ciently accurate to be used in determining recent changes in shoreline. 

 On the other hand, it should be noted that the chart of 1846 indicates 

 a shoreline so nearly like the present shoreline as to warrant the con- 

 clusion that the sea has not been materially closer to the County 

 Road in the last sixty years than it is today, except during unusual 

 storms. Indeed, a chart of Boston Harbor published in the fourth 

 part of The English Pilot in 1709, while not accurate in details, seems 

 to show that no pronounced changes in the shoreline of Nantasket 

 Beach have occurred in the last two hundred years. 



The application of the principles of shoreline development to the 

 interpretation of the present form of Nantasket Beach offers the only 

 means of determining the initial form of the beach. We believe that 

 by this means it is possible to determine with a fair degree of certainty 

 the geography of the Nantasket region before the present beach 

 came into existence. The problem involves the restoration of the 

 lost drumlins of this portion of Boston Harbor. 



There is little difficulty in the restoration of those drumlins which 

 retain their initial form to a considerable degree. The existing drum- 

 lins of the Boston district are of the same general type, none of them 

 resembling the greatly elongated type found in some parts of New 

 York. It is possible, therefore, to complete the outlines of Thorn- 

 bush Hill (T) and Nantasket Hill (N) at Hull, Great Hill (G), Straw- 

 berry Hill (St), White Head (W), Sagamore Head (Sa), and Hampton 



