JDH writes to Charles Lyell about specific points of geological interest encountered on the Ross Antarctic Expedition. Thanks Lyell for giving him Darwin's book with a description of Cape Verde. Also says he values THE GEOLOGICAL RESEARCHER & the profile of Lyell, which he keeps in his cabin with his father & Baron Humboldt's. Describes the Geology of Kerguelen Island & compares it to the account of Captain Cook who knew it as Desolation Island. Rocks incl: Trass, lava, Breccia, whinstone, volcanic conglomerations, basalt configurations, Quartzes & Zeolites. McCormick sent back fossil woods. Letter includes a sketch of Christmas Harbour. Birds incl: endemic Chionis & night Petrel. 3 insects: a Curculio, apterous moth & a spider. Describes the Kerguelen climate. Found more plants than expected: seaweeds, lichens, Mosses & Jungermannia, all perennial South American types. Writes about icebergs near Kerguelen & refers to the theory of erratic boulders which Charles Lyell's son has written about. Describes an agate fossil trunk he found in Van Diemen's Land & his notes on it in TRANSACTIONS OF THE NATURAL HISTORY SOCIETY OF TASMANIA. The Auckland Island flora resembles that of New Zealand. Describes icebergs, first seen at latitude 63 degrees south. At 66°S collected black volcanic rock containing Olivine from an iceberg, which is illustrated. Describes mountainous land mass at 71°S & an island with a penguin rookery. Dredging to 300 fathoms found marine life: chiefly Mollusca, Crustacea, Corals, Bicellaria, some Ophiura & Syenite rock deposited by an ice berg. On an island 76°S observed signs of the different natural means of rock transportation & land formation. Includes a sketch of the ship 'Erebus' anchored off this island's cliffs. Describes discovery of the volcanoes 'Erebus' & 'Terror' incl. sketch. Discusses abundance of Diatoma found in the tow net & stomachs of Salpa & his belief that it is vegetable not animal. JDH has a geological collection for Lyell Jnr.