A description of Dr Black's portable wind furnace will be found in our article on CHEMIsTior, vol. vi. p. 189, and a perspective view and section of it in Plate CXLIII.
7. and 8.
A description of Mr Arthur Aikin's portable blast fur nace is given in the article CtiEmisTity, p. 160, and a per spective view and section of it in Plate CXLIII. Figs. 10, 11, 12, and 13.
Farther information on this subject will be found in our articles GLASS-MAKING, IRON, STOVE, and in several other articles where furnaces are adapted to particular purposes in the arts. See also Lewis' Philosophical Commerce of Arts ; Aikin's Dictionary of Chemistry, vol. ii.; Miche ou Reverberatory Furnaces, in Rozier's Journal, vol. xxxii. p. 385. Perceval's Chamber Lamp Furnace, in the Reper tory of Arts, vol. iii. p. 29 ; and in the Transactions of the Royal Irish Academy, vol. iv. p. 91 ; Watt's Patent Fur naces, in the Repertory of Arts, vol. iv. p, 226 ; Mr Edwat d Howard's Improved Air Furnace is described in Tilloch's Philosophical Magazine, vol. v. p. 190-193, and repre sented in plate iv. of that work ; Raley's Patent Furnaces, in the Repertory of Arts, vol. x. p. 155; Accum's Im proved Universal Furnace of Dr Black, is described in his System of Practical Chemistry, vol. ii. p. 357, and in Ni cholson's Journal, 8vo. vol. vi. p. 273; Curadau's New Evaporating Furnace is described in the Annales de Chimie, No. 149. ?n. xii. and in Nicholson's Journal, 8vo. vol. ix. p. 204-207 ; and Lucas's furnace for cast-iron cutlery, in Parke's Chemical Essays, vol. iv. Ess. 15. A furnace for decomposing the sulphate of barytes, is described in the same work, vol. ii. Ess. 5. (e. s.) FURNEAUX's ISLANDS. The great continent of New Holland is separated from Van Diemen's Land on the south, which was during centuries believed to be an inte gral part of it, by a considerable expanse of water lately discovered, called Bass Strait; and numerous islands, some towards the centre of the strait, and some on the respec tive coasts are interposed between the two territories. These have been classed into groups by successive navi gators, though with little regard to order, and without any decided analogies. One of the principal and most com prehensive is Furneaux's Islands, divided by Bank's Strait, 12 or 15 miles in width, from the north-east extremity of Van Diemen's Land, stretching from about 22' to 41' 27' of South Latitude, and situated, with respect to the centre of the group, in about 148° of East Longitude.
Neither the exact number of islands composing this group, nor their individual size, are completely ascertain ed : the principal are Great Island, Cape Barren Island, Clarke's Preservation, Chappel, and Babel Islands, besides many rocks and islets. The first is not less than forty
miles in length, and the second twenty. Almost all have good harbours for shipping; but the channels among some of them are narrow, and of dangerous navigation.
The basis of the greater part of these islands is a whit ish granite, sometimes inclining to a reddish tinge, and full of small black specks, supposed to be tin, and com municating a deleterious quality to water, as several peo ple died on drinking it. When exposed to heat, fumes es cape strongly denoting the presence of arsenic. The hills rise to a considerable height; the highest is supposed to be 1200 feet. Those of Cape Barren Island are generally crowned with huge masses of granite; and immense de tached blocks of the same substance arc scattered about on the rest. The lower parts of the islands are common ly sandy, or they have swamps and pools, where the wa ter is usually of a tcddish hoc; in other places, it is fresh and good, although transient visitors have denied its exis tence.
The whole islands are overrun with brushwood, inter mixed, in the more sheltered parts, with a few stunted trees, never exceeding twelve feet in height, and several low shrubs grow on the humid grounds, surrounding the margins of pools and swamps; but most of the brushwood as$umes a depressed and creeping form, particularly on 'those sides of the islands exposed to the more prevalent winds. A very singular and unexampled feature is pre sented in some of the trees having undergone a partial pe trifaction in Preservation Island. There, in a particular spot, none of them are thicker than a man's leg ; all are decayed; but while the upper branches consist of wood, the roots at the surface, and the trunks to a certain height, are converted to a chalky substance. The interior central part is always circular, seldom of the same diameter or of the same composition; and rings of the brown wood some times appear, on breaking over the trunks, as if the petri faction were still incomplete. The vegetable productions of Furneaux's Islands are scanty throughout ; and it is to lie observed, that although there are patches of rich and fertile soil, and the most luxuriant •growth of numerous plants in the vast extent of New Holland and Van Die men's Land, a very large proportion of the skirts, for the interior is yet unknown, consists of low sandy tracts, ap pearing as if recently reclaimed from the sea, and where nature is seen in her most barren aspect.