476 Proceedings of the Royal Society 
traditionary names and curious legends by which many of them 
are known. Such names as the Carlin’s Stane, the Witch’s Stane, 
Pech or Piet’s Stone, Clachannadruid, Kirk-Stane, Pedlar’s Stane, 
Thuggart Stane, and Devil’s Putting Stane, are all applicable to 
rounded blocks. 
When the geologist turned his attention to the subject, it was 
soon discovered that there were many blocks equally entitled 
to be called erratic, not round but square shaped ; and which, 
though discovered to belong probably to rocks at a great distance, 
yet showed signs of little or no attrition. Moreover, many of these 
angular or sharp-edged blocks were comparatively soft and loose in 
structure, so that they could not have been rolled, for any con- 
siderable distance, without being broken or crushed into pieces, or 
into sand or mud. 
On a more minute inspection and study of these erratic blocks, 
certain features were noticed which seemed to indicate the forces 
to which they had been subjected. Thus on many of them, deep 
scratches, ruts, and groovings were found, as if sharp pebbles or 
stones harder than themselves had been pushed over them, or 
squeezed against them under great pressure. It was also observed 
that, when a block had a long and a short axis, the longer axis was 
generally parallel with any well marked scratches or striae on 
their surface ; and moreover that the direction of these striae fre- 
quently coincided with the direction in which the block itself had 
apparently come from the parent rock. 
These circumstances soon led geologists to speculate on the 
nature of the agencies which could have effected a transport 
of the blocks. Some blocks are of enormous size, exceeding 
1000 tons in weight.* Many, before they could have reached the 
places where they were found, must have travelled fifty or sixty 
miles, and have crossed valleys and even ranges of hills. In the 
county of Berwick, for example, there is a large block of gneiss, a 
rock which exists nowhere in that county or in the south of Scot- 
land; and if it came from some of the hills in the Highlands, it 
must have crossed, not only the valley of the Forth, but the Kil- 
syth, Pentland, and Lammermoor Hills. 
* The celebrated block near Neufchatel, called “ Pierre a bot,” contains 
about 1480 cubic yards of stone, and is supposed to weigh about 2000 tons. 
