GLACIAL DRIFT. 
291 
Kingston,—lenticular mass, on south-west z. Two or three seams of sand, in- 
Sidesof Great hil a venaGcaeindocmavasieniawints 5 25 clined 45°, 3-6 inches wide and several 
East Kingston,—lenticular mass, on south- feet long, occur in the lower till, which is 
east side of Great hill................ 3 60 underlain by a stratum of black clayey 
Kensington,—Moulton ridge, lenticular hill, sand 1 foot or more in thickness. 
At LOD avs iecessresasarsinsiaraeoveroinvetonagiaie wean a aire 10 30 o. Upper and lower till separated by 
priile south Of 1460 occu ourwew yp civesaxs 17 5 a layer of sand 4 inches thick. 
Top of lenticular hill, south of Muddy i 
PONG sa vacscerais-viorarerscenersienste aeieienein Sees 5 15 p-. Upper and lower till separated by 
North-west slope of same hill........... 13 15 | %. | 6 inches of waterworn gravel. 
South Hampton,—north-west village......... 6 10 
The average thickness of the upper till, obtained by taking the mean 
of these observations, is three feet and nine inches. If we subtract one 
tenth of this, due allowance will probably be made for areas that are 
» 
Fig. 61.—SECTION OF GLACIAL DRIFT, TWO MILES EAST OF ASHLAND, 
illustrating the usual mode of occurrence of the upper and lower till 
throughout the state. 
Thickness of the upper till, 4 feet; of the lower till, 25 feet. The most 
abundant boulders in the former were porphyritic gneiss; in the latter, 
Montalban. 
destitute of this deposit, leaving three and one third feet, which would 
thus appear to be approximately the mean depth of the upper till, if it 
were spread in a sheet of uniform thickness over the entire state. 
The lower till, however, does not appear to have any development 
upon half of this territory, being accumulated in patches, sheets, and 
lenticular masses, while over adjoining areas of equal extent the ledges 
are exposed or covered only by the upper till. Very few of these sec- 
tions show the whole thickness of the lower till; and its depth in the 
lenticular hills affords no basis from which to judge of its other deposits. 
It is impossible, therefore, to arrive at an estimate, as before, from this 
table. If we still wish to form some conclusion respecting the entire 
mass of the ground-moraine, it will be well first to consider the lenticu- 
lar hills and slopes, of which about eight hundred and sixty have been 
