- Forum Auctions (auction)
- Natural History Museum, London: NHM WP1/8/272
- British Library, The: BL Add. 46437 f. 51
ARW mentions a reviewer in Science noticing ARW's paper on "The Gorge of the Aar". Many Swiss geologists have proved that some Alpine lakes are due to subsidence or deformation, ?see Aeppli's essay on Lake Zurich. ARW asks for references to these proofs.