THE HAWKESBURY SANDSTONE. 75 
_ The difficulties in the way of such an explanation are insur- 
mountable, as I shall show at the end of this paper. The wa 
 gecount for these boulders is that they are the results of the action 
of creeks or flows of water in the loose. sandy hillocks, These 
_ would easily undermine the beds of shale and break them up, 
tossing large fragments on end, and mingling them with water- 
worn pebbles of the watercourse. A few > dry wind would 
soon entomb these ruins in sand and turn the course of the 
Here are a few examples :—In August, 1829, a ent of 
sandstone, 14 feet long, 3 feet wide, and 1 foot thick, was 
carried by the river Nairn, in Scotland, a distance of 200 yards 
On the same occasion the river Dee swept away a bridge of 
five arches, built of solid granite, which had stood uninjured for 
twenty years ; the whole mass of masonry sunk into the bed of 
m and was seen no more. And the river Don, as we 
ate assured on the authority of Mr. Farquharson, forced a mass of 
stone, four or five hundred tons in weight, up a steep inclined 
‘Plane, leaving them in a great rectangular heap on the summit. 
A small rivulet called the College, in Northumberland, when 
§wollen by a flood in August 1827, “tore away from the abutment 
ofa mill-dam a large block of greenstone—porphyry—weighing 
fla and transported it to the distance of a quarter of 
: Glazed surfaces.—In these blocks of shale there is often a dis- 
Pesition to divide into small blocks of irregular form but curiously 
: glazed surfaces, I have noticed the same in carbonaceous allu- 
: i sa peer places, The creeks near Bathurst are, in the neigh- 
gorges as are found in the Blue Mountains. It 
» remembered that there is not the slightest evidence of 
oe or subsidence, except at the downcast already mentioned, 
S were rath, ybralasy ivan have remained. In the 
eee eis Rhee 
