of Edinburgh, Session 1883 - 84 . 
899 
from W-N-W. [Abstract, p. 870). On the island of Papa Stour 
there are blocks which apparently came across St Magnus Bay from 
a IST.E. direction [Abstract, p. 867). Butin other cases the boulders 
on the islands must have been floated from many different directions. 
It is also proper to notice the fact, that in some of the islands of 
the Hebrides, and even on portions of the west coast of the Main- 
land, the positions of the boulders indicate a movement, not from 
W.N.W. (the normal direction for Scotland generally), but from H. 
or H. by E., as in Islay [Abstract, p. 806), in Iona [Abstract, p. 
808). Loch Fyne [Abstract,^. 777); Kintyre [Abstract,^. 773). 
Buteshire [Abstract, p 791). 
But these exceptions do not greatly detract from the value of the 
generally concurring evidence, everywhere else, of a direction from 
W.KW. 
It is also an important circumstance that the part of Scotland 
where the boulders are largest, heaviest, and most numerous, is 
along the west coast (see p. 886). If floating ice brought boulders 
across the Atlantic, the first place where boulders would be dis- 
charged would be where the sea bottom rose high enough to inter- 
rupt the progress of the ice. The ice carrying the largest and heaviest 
boulders would most probably strike the sea bottom soonest ; whilst 
the ice carrying smaller cargoes would flow on, till these reached the 
submarine rocks which now form the present inland mountains. 
As bearing on the question, whether land ice or sea ice was the 
transporting agent, another circumstance brought out in the Reports 
must be kept in view. Some boulders on the tops and ridges 
of mountains are at heights far above what could be reached by 
a glacier having its birthplace in any adjoining district. Such 
are the boulders at heights exceeding 3000 feet ; and even when 
at lower heights, it would be necessary, for upholding the glacier 
theory, to have mountains pointed out where glaciers could have 
been formed, and with a valley through which the glacier could have 
flowed in the direction of the boulder. But even if this difficulty of 
levels could be overcome, there is still another in explaining how a 
glacier could set down on the very tops of hills, or on excessively 
steep slopes of hills, boulders which are frequently seen in these 
critical positions. 
Floating ice stranding on mountain tops or slopes, might, by 
