of the Scratched Rock Surfaces. ne 
in Finland, at the White Sea, and on the northern glacial 
ocean, the striation radiates outwards. 
If, then, there was a stream, it was not moving in any one 
direction alone, but must have had, in addition, an outward 
lateral motion along the axis of its general course; and the 
question arose whether the motion was from one centre or 
from several. The utmost attention was now directed to the 
striations in various localities, and hundreds of observations 
were collected ; blocks were carefully tracked back to their 
original site, the weather or exposed, and the lee side of 
rocks were attentively noted, and the materials accumulated 
became enormous. These were tabulated on maps by 
Horbye and Rordam in 1857, &c. 
As to the direction of the scratelies, there can be now no 
doubt; but till this was ascertained, the question whence 
and Ghether the grinding down proceeded could only be 
determined from the somewhat doubtful indications of the 
‘weather and lee sides” and the boulders. Now, however, 
if we examine the maps, we shall observe spots from which 
the arrow markings radiate out in different directions. 
Such spots must have been the centres of motion, and they 
lie, it will be found, in the higher districts of our mountains; 
or where, at a lower level, they occur in the form of cross 
scratches, they may indicate the successive application of 
friction in slightly different directions. 
Thus far, then, we have got; the phenomenon itself is no 
fiction, however erroneous may be the explanation of it by 
a flood. Innumerable observations with the compass have 
shown that the scratches and striations are there, that there 
must further have been various centres whence the pheno- 
mena originated, and finally, that in some places at least, 
the force has operated again and again. 
When now we consider that glacier ice, with the debris 
which it carries along with it, produces striations on the 
surface of the rocks over which it is ever, though slowly, 
advancing ; when we consider, further, that a glacier moves 
boulders either involved in the debris of the end and side 
moraines, or in the form of huge, scattered, sharp-angled 
blocks, which in one way or other have reached the surface 
of the glacier, and now share in its movements, we may 
