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Proceedings of the Eoyal Society 
The fact of there being two such streams, suggested the proba- 
bility of there being others ; so, as both of these streams indicated 
a direction about east and west, he resolved to cross the country 
in a north and south direction elsewhere, at the same time 
following, as much as possible, the ridges of the hills lying that 
way, and climbing to the summits, for the sake of having an 
extensive view. Being accompanied in this expedition by two or 
three friends, each provided with a binocular, it was not likely that 
boulders of any size, visible within half a mile of the route followed, 
would be missed. 
Professor Heddle carried with him an Ordnance map with contour 
lines, which at once indicated the heights of the hill ranges, and on 
these he has drawn, with a thick red line, the exact route taken. 
This map he has sent to the Convener. To him it has been of 
much service by enabling him to follow the Professor’s notes. 
But, before specifying the names of the hills visited, and the 
results, it is not unimportant to notice some remarks by the Pro- 
fessor of a general nature bearing on the best way of boulder 
hunting. 
He states that former explorations had impressed upon him the 
advantages of making a search chiefly along hill ridges, and of scaling 
hills to their summit. In the first place, a more extended range 
of observation is obtained, and in the second place there is more 
probability of finding the boulders in their original positions. 
If boulder hunting is carried on in glens or valleys, as has 
hitherto usually been the case, the range of observation is exceed- 
ingly limited ; — whereas, from a hill top, a panorama of a wide 
range of country may be obtained, which, besides showing boulders, 
makes the gradients of the country more intelligible, and indicates 
where there may have been passages for ice, whether land or 
sea ice. 
Another advantage is, that if boulders are met with on hill tops 
or hill ridges, it is almost certain that they occupy the position in 
which they were originally placed by the agent, whatever it was, 
which brought them. But boulders in a valley, or on the sides of 
a valley, may have rolled down from a higher level, and thus afford 
far fewer data for safe reasoning. 
Professor Heddle observes that there are ranges of hills of con- 
