All About Engines

34 All About Engines was a huge contrivance, considering the tools and workmanship of the day. The cylinder was 47 inches in diameter, and the speed of working was fifteen strokes a minute. The mine was 30 fathoms, or 180 feet, deep, and the barrels of the pumps were 15 inches in diameter. About 800 gallons were raised per minute. The engines were soon in use all over England, though only a few appear to have been made by Newcomen himself. Some were built by Smeaton, the famous engineer who built the Eddystone Lighthouse, and who had seen the Aus- thorpe engine at work when a boy. In the districts where coal was cheap the engines were successful, but in Cornwall they were terribly expensive to work. The cylinders of some of the engines were 5 and even 6 feet in diameter ; while one at the Walker Colliery, near Newcastle, was 7J feet in diameter and had a io-foot stroke. At every stroke this cylinder had to be filled with steam —aye, more than filled, for on entering the cold chamber much of it was condensed. Some of the Cornish engines consumed 13 tons of coal a day I Again, the workmanship was very imperfect. Some of the engines constructed or repaired by Brindley had wooden cylinders, built up like a barrel, and held together with iron hoops! The lower portions of the boilers were made of copper, and the upper portion of lead ! But for a time it kept water from the mines, enabled the miner to pursue his calling, and enabled coal especially, which was now, in the first half of the eighteenth century, coming into use