TRANSACTIONS OF SECTION C. 1019 
Its form and position were until lately accepted as proving it to be of artificial 
origin, and speculation dealt only with hypotheses of the reason of its being erected. 
Some of these, being of a superstitious character, increased the unwillingness to 
have the mound dug into which veneration for its antiquity and its traditional 
history occasioned. The character of the great mound was discovered by accident 
in 1883, when a burying ground was being prepared around its base. 
The Bass has a prolongation half the height called the Little Bass. In laying 
out the graveyard a walk was made round the conical portion, so as to complete 
the outline of the cone. A way had to be excavated between the Bass and Little 
Bass. The work showed for a day or two a vertical section, which, being observed, 
was examined by a geological expert and pronounced to be clear evidence that the 
hill was produced by successive deposits of sand laid down in the valleys of the 
Don and Ury, until a sand bed lay there whose surface was of the height of the top 
of the Bass. Upon that level, 40 feet higher than the present level of the Don and 
Ury, these streams flowed before the Bass began to be formed ; and in course of time 
it was gradually formed by denudation, something accidentally protecting a spot of 
surface while the streams washed away the soil around. ‘The river beds were 
gradually deepened, while the Bass, once begun to stand up out of the flood, got 
broader and broader, turning the two converging streams aside. 
The alluvial origin of the Bass infers the existence of a breadth of flowing 
water over the whole range covered by the sand bed, which can be traced five 
miles back from the Bass in the line of both rivers. The existence of that lake 
infers the existence of others between it and the sea. Ordnance levels and existing 
rocky narrows in the line of the Don point out the outlines of those lakes. 
The continuing preservation of the form of the Bass, notwithstanding that the 
Ury impinges upon it at right angles, is due to the circumstances that a bed of 
boulder clay 30 feet wide underlies the Ury and the centre of the Bass. The 
boulder clay was discovered in building a wall for the graveyard, and the bed has 
since been found a mile south in digging a well at the Inverurie paper mills. It is 
there 46 feet thick. 
6. Thirteenth Report on the Erratic Blocks of England, Wales, and Ireland. 
See Reports, p. 322. 
7. The Direction of Glaciation as ascertained by the Form of the Strie. 
By Professor H. Carvitt Lewis. 
As there seemed to be a disagreement between certain Scotch geologists and 
the Irish geologists regarding the inferences as to the direction of glaciation to be 
deduced from the form of glacial striz, the author was led to bring forward some 
observations of his own, made in America and in Great Britain, which threw light 
upon the disputed point. 
Well-preserved strise are frequently blunt at one end and tapering at the 
other, the shorter ones.sometimes resembling the characters used in the cuneiform 
inscriptions. This form may be seen in strize of all sizes—from those several yards. 
in length, when the blunt end may be an inch or more in breadth, to the finest 
scratches, where a microscope is necessary to detect any ditference between the 
two ends. 
As shown in the Reports of the Boulder Committee of the Royal Society of 
Edinburgh! and elsewhere, certain Scotch geologists regard the blunt end as the 
point of impact of the striating agent, and as therefore pointing to the direction 
from which the motion came. On the other hand, the Irish geologists? interpret 
the shape of the strize as indicating motion in the opposite direction, believing the 
tapering end to point to the direction from which glaciation proceeded. The point 
1 Fifth Report, pp. 18-20, 29, 58 ; and Seventh Report, p. 18. 
2 Memoirs Geolog. Surv. of Ireland, Explanation to sheets 86, 87, 88, p. 55 
Explanation to sheet 193, p. 18, &c. 
