valley proved most unfavourable, and the very heavy rain which fell without ceasing throughout the day, drenching us all thoroughly to the skin, prevented that full investigation which we had desired, and hurried all our operations, so that the erratic blocks or boulders of basalt, of which Strzelecki has given so perfect and animated a description, were only superficially examined by us, but as his account of them is of so much interest both to the geologist and general reader, I prefer inserting it to giving my own. Notwithstanding the unfavourable weather, we all greatly enjoyed our excursion, thanks to the polite attention and true English hospitality of Mr. Barker and his family. Strzelecki proceeds to remark[1], that "not less wonderful, and equally interesting, are the erratic blocks or boulders found in the same valley of the Derwent. The masses are composed of cylindrical, somewhat flattened, columns of basalt, confusedly heaped together, with a detritus of pebbles mixed with spheroidal boulders of greenstone rocks, all lodged against an escarpment situated at the bottom of the valley, and on the right hand of the Derwent.
"This escarpment belongs to the carboniferous strata, and was once connected with another escarpment running across the bed of the river, so as to dam up the present outlet of the waters, and thus to form, in conjunction with the other lines yet existing, the perfect and continuous margin of a basin. The violence with which this embankment
- ↑ Strzelecki, Physical Description, p. 148.
