" 
‘Altar’ 
2,Micaceous Grit. 
Sarsen Stone. 
1 
20.Hoare. 
NG 
: 
(or altered Dolerite 
3 & 4, Diabase 
6, Felstone. 
, Corstorphine Hills. 
_ §,Diabasic rock 
T Hollick del etlith. 
Mmtern Bros. imp. 
MICROSCOPE SECTIONS IN ILLUSTRATION OF THE 
PETROLOGY OF THE STONES AT STONEHENGE. 
