PARALLEL ROADS OF LOCHABER. 109 
The following woodcut is a case which very frequently occurs. 


] \ 
Sq 
N 
WN 











N.W. = S.E, 
Glen Spean.—Large boulder, partly leaning on smaller boulder. The former ap- 
parently came from N.W. in order to obtain its position. Lower part of Glen 
Spean lies to N.W. If Boulder had come from Loch Treig (which lies to 
W.S.W.), it would have gone past smaller boulder, and not rested 
on it. 
The following woodcut, is another case of the same kind, 
’ es 
' 
it Ni \ : 
S.E. 

LL 






Glen Spean.—\arge boulder, 3 feet high and 5 feet wide, leaning on a 
smaller boulder. A line drawn through the point of contact and the centre of 
gravity of the large boulder runs N.W. by N., 7.c,, down the centre of Glen 
Spean, indicating that the boulder came up Glen Spean, If it had come from 
Loch Treig, it would not have been in this position, 
VII. Dr Tyndall’s Lecture. 
Dr TYNDALL in the outset states, that being an old student of glacial action, 
it was not inappropriate that he should take that side in the discussion. 
VOL. XXVIII. PART I. QE 
