Long before Watt’s arrival in Birmingham, the Cornishmen had been in correspondence with Boulton, making inquiries about the new Scotch invention, of which they had heard; and Dr. Small, in his letters to Watt, repeatedly urged him to perfect his engine, with a view to its being employed in the drainage of the Cornish mines. Now that the engine was at work in several places, Boulton invited his correspondents in Cornwall to inquire as to its performances, at Soho, or Bedworth, or Bow, or any other place where it had been erected. The result of the inquiry and inspection was satisfactory, and several orders for engines for Cornwall were received at Soho by the end of 1776. The two first that were ready for erection were those ordered for Wheal Busy, near Chacewater, and for Tingtang, near Redruth. The materials for the former were shipped by the middle of 1777; and, as much would necessarily depend upon the successful working of the first engines put up in Cornwall, Watt himself went to superintend their erection in person. [Illustration: MAP OF UNITED MINES DISTRICT.] Watt reached his destination after a long and tedious journey over bad roads. He rode by stage as far as Exeter, and posted the rest of the way. At Chacewater he found himself in the midst of perhaps the richest mining district in the world. From thence to Camborne, which lies to the west, and Gwennap to the south, is a constant succession of mines. The earth has been burrowed in all directions for many miles in search of ore, principally copper--the surface presenting an unnaturally blasted and scarified appearance by reason of the “deads” or refuse run out in heaps from the mine-heads. Engine-houses and chimneys are the most prominent features in the landscape, and dot the horizon as far as the eye can reach.