David Napier by David Napier and David Bell: Note 3
3. DUMBARTON ENGINE
The description given of this engine indicates that it was of the Newcomen or Atmospheric type, which continued in favour long after Watt's engine had been introduced. Engines of this description were used in steam-vessels till a comparatively recent date. In 1856 Seaward and Capel fitted atmospheric engines to a steamer, having three cylinders of 62 inches diameter; and a Jersey steamer with open-top oscillating cylinders was running till about 1868. Many atmospheric engines of large size were also in regular use in Lanarkshire and Ayrshire till about 1870, gradually giving place to more efficient motors. One of these employed at a colliery had a cylinder 60 inches diameter and 7 feet stroke. Another of smaller size continued at work at Caprington Colliery till 1901, having then completed ninety-five years' service. It is now preserved in the Dick Institute, Kilmarnock An engine of this type, still at work (1912), belongs to the Farme Coal Company, Limited, Rutherglen, near Glasgow. It was constructed there in 1810 or 1811, and has been in constant service since then, with only occasional short interruptions for overhaul. The cylinder, which was never bored, is 32.25 inches diameter and 5 feet 6 inches stroke. It is open at top, and the piston is packed about twice a year with hemp, which, with a little water, keeps it sufficiently tight. Steam of five to six pounds per square inch is admitted by a hand lever, the reverse movement of which allows a jet of water for condensation to be injected through the bottom of cylinder, supplied from a tank placed about ten feet above same and kept filled by a pump on the engine. With twenty-seven to thirty revolutions per minute about thirty horse-power is obtained, the work done consisting in winding up coal from a depth of about forty-three fathoms.
It is not known what became of the Dumbarton engine when John Napier left Dumbarton.
In 1825 over three hundred steam-engines were at work in or near Glasgow, some no doubt of the Newcomen type, but the only one mentioned as of unusual construction was a "rotatory" of sixteen horse-power, in use at Govan Colliery.