Hi - this is snipped from a 1732 Prospect of Birmingham, from the South-East . . . the twin chimneys along the furthest (Northern) edge are "Kettle's steel-houses" . . . in the right-ish mid-ground, in its little fenced domain by Cole's Hill Street, is: "Carlesse's steel-house" . . . all 3 have the tell-tale form of cementation furnaces, doing their roughly week-long thing. Just 21 years later, this East Prospect by the Buck brothers - from a similar tho' not identical viewpoint - shows in the Northern distance the two chimneys to Kettle's steel-houses; though now these furnaces are along the Southern edge to the new "Gun Quarter". The same straight street alignment along John Street/Newton Street runs from Cole's Hill towards them. But the mid-ground is now dominated by St. Bartholomew's Chapel (1749) & the plural chimneys of Turner's Brass House (c1748) . . . neither occupy the exact site of the vanished: Carlesse's Steel-house; of which - by the time of this image - there is no obvious trace. . . . research has brought confidence in William Smith being a Birmingham steel saw manufacturer at or before the 1730s; slightly less so of Robert Stidman . . . . each have substantial premises in central Birmingham c1740. (EDIT) Abraham Spooner (an iron-importer, much of it to Birmingham) stated, in his evidence to the House of Commons on 20th April 1737; that c220 tons of steel was made annually in Birmingham - presumably in these above 3 furnaces, recorded 5 years earlier. Samuel Schröder, in his report of a visit to Birmingham in 1750, stated that the (Kettle) twin Steel-houses produced about 150 tons a year between them . . . . we might not be entirely mistaken if we assume the 3rd (Carlesse's) Steel-house to have been similar in its annual output; at 70-some tons. Each charge was of roughly 5 tons of Swedish 'Oresunds' (or very similar) bar-iron, at roughly £17 per ton landed at Bewdley - the nearest riverport. By the time each furnace was loaded with bar & fuel & any Secret Sauce perhaps £100 would have been spent . . . . a serious amount of money in the 1730s & a serious responsibility on the artisans tending the 5 - 8-day burn. NB - much of the above point is made in Ken Barraclough's 'Steelmaking before Bessemer' (volume 1), & in his Doctoral thesis