By 1725 the picture has changed dramatically and the details are provided by Henric Kalmeter in his journal. Chyandour now has four reverberatory furnaces having been converted from a blowing houses in 1717. Ludgvan has has two reverberatory furnaces opened in 1724 to replace the old blowing house. Treloweth, at Rose an Grous, has three reverberatory furnaces erected in 1720 and lastly, Trereife has four reverberatory furnaces dating from about 1716. In addition there are now three furnaces at Lelant and six at Angarrack, both of which might well have sent tin to Penzance to be coined. Not only has the technology changed to meet the demands of lode mining but the capacity has increased hugely. Kalmeter gives a figure of 1,120 ingots (about 160 tons) coined in Michaelmas quarter.

The Chyandour smelter with its four stacks, one for each furnace (photo courtesy of Morrab Library Photo Archive)

via http://www.penwithlocalhistorygroup.co.uk/on-this-day/?id=201