BLOCKS DIMINISH IN SIZE FROM NORTH TO SOUTH. 
523 
the slopes or sides of the hills, and occasionally in thick groups : the tracts be- 
tween Schwerin and Lubeck on the east, and again around Seelaw on the right 
bank of the Oder, being fine examples. In the rapidly undulating country between 
the Oder and Posen, particularly at the village of Kahorl, the largest boulders (all 
much-rounded) are found on the north side of a little hill. In some districts they 
occur at intervals, and seem more equably scattered about. In many others, par- 
ticularly in Pomerania, they occupy irregular lines or trainees ranging from north to 
south. Thus also, in the sandy plains east of Posen, not a block is to be seen for 
several miles from east to west ; but the moment you reach the small elevations, 
somewhat more argillaceous, which rise towards the Polish frontier, they are 
again numerous. In that frontier sandy plain, the blocks are usually small, but 
in the hills between Konin and Kol&a, the subsoil of which is composed of tertiary 
claystone as white as chalk, loads of large blocks are buried in and mixed with 
gravel and sand, at heights of 300 or 400 feet above the sea. In passing from 
west to east, the traveller is here struck, as in Russia, with the great change in 
the character of the blocks in each new degree of longitude, showing that they 
have been derived from different districts of Scandinavia and have been distributed 
in trainees ; for whilst to the west of Posen they are nearly all granitic, to the 
east they are chiefly of quartz rock or altered sandstone. In the richly cultivated, 
argillaceous and loamy plains between Kolaa and Warsaw, the detritus is more 
equably spread about at rarer intervals, and not in groups. At Warsaw the ex- 
cavations made for brick-earth, expose a subsoil of incoherent white sand inoscu- 
lating with some clay, and occasionally containing small pebbles of quartz rock 
and Lydian stone ; the whole representing the tertiary beds of the region. These are 
covered by the drift clay and loam, with erratic northern blocks upon the surface. 
The drift of Russia and Germany, in common with that of England, exhibits, 
for the most part, a diminution in the quantity and size of the blocks, the further 
they have ranged from the source of their origin. Hence, in the parallel of Mos- 
cow, to which place and far beyond it they extend, the fragments of granite and 
greenstone seldom exceed two or three feet in diameter , whilst near St. 1 eters- 
burg their diameter is often as many yards. In passing from the White Sea to 
1 The larger blocks are rapidly disappearing, being broken up for the chaussbes and for building pur- 
poses. The observation in the text, that the blocks dimmish in size as they are traced to the south, is, 
it must be understood, liable to exceptions, there being examples of large blocks at great distances from 
their origin,, which can, we believe, only have travelled thither in floating icebeigs. 
