2047. Another era of improvement may be dated from the time when Dr. Anderson published a treatise on his patent hothouse, and from the publication of Knight's papers in the Horticultural Society's Transactions, both of which happened about 1809. Not that the scheme of Dr. Anderson ever succeeded, or is at all likely to answer to the extent imagined by its inventor; but the philosophical discussion connected with its description and uses excited the attention of some gardeners, as did the remarks of Knight on the proper slope of glass roofs (Hort. Trans., vol. i.); and both contributed, there can be no doubt, to produce the patent hothouses of Stewart and Jorden, and other less known improvements. These, though they may now be considered as reduced au merite historique, yet were really beneficial in their day. Knight's improvements chiefly respected the angle of the glass roof; a subject first taken up by Boerhaave more than a century before, adopted by Linnï¾µus (Amï¾µn. Acud., i. 44.), and subsequently enlarged on by Faccio in 1699, Adanson (Families des Plantes, tom. i.) in 1763, Miller in 1768, Speechly in 1789, John Williams of New York (Tr. Agr. Soc. New York, 2d edit.) in 1801, Knight in 1806, and by some intermediate authors whom it is needless to name.