430 
The Hon. Mr. Strangways on the 
strata from Cargasary to Tzarscoe Celo as accurately determined, 
though they cannot be far wrong. 
The most striking phenomenon attending this branch of geological 
research, is the enormous quantity of boulders, or large rolled blocks, 
found either on the surface of the soil, or half, or entirely buried in 
the diluvian gravel, of which they must be considered as members. 
I cannot pretend to enumerate all their varieties ; the following are 
the principal. 
Primitive Rocks . 
Large grained glandular granite, containing much black horn- 
blende and red felspar : much used for ornamental purposes when 
sound, but in it general disintegrates easily by the action of the 
atmosphere, crumbling between the fingers without difficulty. 
Some of these, though retaining their upright position, are cut down 
and quarried for the gravel they afford for the roads : they are some- 
times found in a rugged heap of gravel, and their surface in general 
retains little of its waterworn smoothness. 
In situ; Baron Nicolai’s quarries near Wyborg. 
Rolled passim; perhaps the most common species: coarsegrained 
gneiss or granite slate, grey and red, with iron. 
In situ ; Imatra, and interior and western parts of Finland. 
Rolled ; frequent near Petersburg. 
Yellowish green felspar rock, with garnets of large size. 
In situ ; said to be so between Kexholm and Cerdopol. 
Rolled ; near Strelna. 
Small grained grey granite, hard, often irregularly laminated. 
In situ ; unknown. 
Rolled ; common. 
