ERRATIC BLOCKS OF THE BRITISH ISLES. 175 
brought to its present position by human agency from adjacent beds of 
drift 
Leicester (Vass’s Brickyard).—A small block of Mount Sorrel granite, 
15 in. by 8 in. by 6 in., has a rounded surface, and there are other smaller 
blocks, chiefly of granite, but also of slate, probably from Swithland, 
in proximity, with quartzite pebbles. 
Leicester (County Brick Works).—A large roughly trigonal or threc- 
sided boulder of Mount Sorrel granite, has a facetted contour. It is much 
pitted and fretted. It contains patches of darker colour, which may be 
“segregation masses.’ It measures 38 in. by 38 in. by 34in. The edges 
are more or less rounded. 
Leicester (between Leicester and Thurmaston), Star Brick Works——Here 
there are many boulders, varying in size from cubes of 2 ft. to 3 ft., and 
various types of sandstones and quartzites. Several slabs of sandstone, 
measuring circ. 1 ft. by 8 in. by 6 in., are quite flat upon one side, rounded 
or roughly quadrangular on the other. Small angular granite boulders 
occur in the river-gravels at this point. Many of the small pebbles and 
boulders in the latter are normally horizontally bedded, but others occur 
im situ, like Bunter pebbles—which many of them undoubtedly actually 
are—with the longer axis vertical. It is difficult to account for this 
phenomenon except by assuming the existence of somewhat turbulent 
currents at certain points, or eddies, accompanied by pounding and rapid 
deposition of sand and gravel, which would tend to arrange the larger 
blocks in a manner not consistent with the normal relation between the 
specific gravity of the boulders and the surrounding matrix. 
Leicester (Belgrave Brick Co.).—In drift overlying red marl a small 
boulder of Mount Sorrel granite and many small quartzites, much resem- 
bling the Hartshill quartzites, and milky white flints, occur. 
_ Levcesier (Barrow’s Brick Pit, West of the Midland Railway).—Countless 
rounded quartzite pebbles, some like the liver-coloured variety, but 
varying greatly in colour and texture, occur, and rocks of northern origin 
are intermixed with others, such as granite, millstone grit, Coal-measure 
sandstone, &c., of local or Derbyshire origin. Filints are not so plentiful 
as at the last locality, immediately south. One mass of granite (15 in. by 
8 in. by 6 in.) has a curiously rectangular shape, with a regularly pitted 
and polished surface, soapy to the touch. Millstone grit is pretty abundant, 
and some dark rocks and a banded slate, probably from Charnwood 
Forest. The size of the rounded quartzite pebbles, many of which are 
derived from the Bunter, is remarkably uniform, varying from 3 in. or 4 in. 
to 6 in., some few more, some less. The shape, too, is characteristic, and in 
their outline one can see an originally quadrangular shape, or occasionally 
a much more irregular original contour. All degrees of smoothness and 
angularity are represented, and the origin of these pebbles must be 
extremely heterogeneous, for when split open they betray very diverse 
sources, the colour, texture, hardness, composition of the quartzites 
being very variable, every gradation between a true quartzite and a 
coarse or fine sandstone or grit existing. 
Thurmaston Brick Co.’s Pit.—Several large blocks of Mount Sorrel 
granite, one very large block of Coal-measure sandstone, Rhaetic and Lias 
limestone, and bolite, varying from cubes of 2 ft. to 3 ft., are found here, 
indicating a mixed origin of the drift beds above the Quartzose sand. 
