Mr. Crawshay employs upwards of five thousand men in his works only; but to form an estimate of the numbers employed, and the produce of iron afforded, I subjoin the following list of the principal works in the vales from Abergavenny to Neath, each furnace producing, on an average, from forty-five to seventy tons of iron per week. The two large furnaces, belonging to Messrs. Crawshay, near to Merthyr, are said to have furnished, for a short period, upwards of one hundred tons each per week. FURNACES. Clydac, or Llanelly (in the parish of latter) Freer 2 furnaces Blenavon, Hill 4 The Varteg 2 Nant eglo, Bayley 4 Beaufort, Kendal 3 Ebro Vale, Harford 2 Sirhowy, Harford 2 Tredegar, S. Homfray and Co. 5 Romney, Mrs. Hall 2 Dowlass, Guest and Co. 8 Penydarran, Forman and Thompson 5 Cyfartha, Crawshays 8 Plymouth, R. I. and A. Hill 5 Aberdare, formerly Thompson and Scales, now Scales 3 and Co. Abernant, ditto, Tappendens 1 Hirwaen 2 Myers and company, four miles short of Neath, charcoal furnace, &c. The immense collections of cinder, or refuse from the ore, astonish the beholder: it appears almost incredible, that the labour of man could transport such quantities of materials; but when, added to this, you reflect that nearly the whole has passed through the furnaces, and been moved two or three times, how much is the wonder increased! In short, to witness what immense capitals, indefatigable industry, and human ingenuity can accomplish, in dragging forth the bowels of the earth, the vales of the Taff from Brecon to Cardiff, and the very numerous vales running parallel with the Taff, betwixt Abergavenny and Neath, should be explored, both above ground, and in the mines; the value of the inclined planes and rail-roads only would be immense.