<P> A number of Newcomen engines were successfully put to use in Britain for draining hitherto unworkable deep mines, with the engine on the surface; these were large machines, requiring a lot of capital to build, and produced about 5 hp . They were extremely inefficient by modern standards, but when located where coal was cheap at pit heads, opened up a great expansion in coal mining by allowing mines to go deeper . Despite their disadvantages, Newcomen engines were reliable and easy to maintain and continued to be used in the coalfields until the early decades of the nineteenth century . By 1729, when Newcomen died, his engines had spread to France, Germany, Austria, Hungary and Sweden . A total of 110 are known to have been built by 1733 when the joint patent expired, of which 14 were abroad . In the 1770s, the engineer John Smeaton built some very large examples and introduced a number of improvements . A total of 1,454 engines had been built by 1800 . </P> <P> A fundamental change in working principles was brought about by James Watt . With the close collaboration of Matthew Boulton, he had succeeded by 1778 in perfecting his steam engine which incorporated a series of radical improvements, notably, the use of a steam jacket around the cylinder to keep it at the temperature of the steam and, most importantly, a steam condenser chamber separate from the piston chamber . These improvements increased engine efficiency by a factor of about five, saving 75% on coal costs . </P> <P> The Newcomen engine could not, at the time, be easily adapted to drive a rotating wheel, although Wasborough and Pickard did succeed in doing so in about 1780 . However, by 1783 the more economical Watt steam engine had been fully developed into a double - acting rotative type with a centrifugal governor, parallel motion and flywheel which meant that it could be used to directly drive the rotary machinery of a factory or mill . Both of Watt's basic engine types were commercially very successful . </P> <P> By 1800, the firm Boulton & Watt had constructed 496 engines, with 164 driving reciprocating pumps, 24 serving blast furnaces, and 308 powering mill machinery; most of the engines generated from 5 to 10 hp . An estimate of the total power that could be produced by all these engines was about 11,200 hp . This was still only a small fraction of the total power generating capacity in Britain by waterwheels (120,000 hp) and by windmills (15,000 hp); however, water and wind power were seasonably variable . Newcomen and other steam engines generated at the same time about 24,000 hp . </P>

What economic and social changes did the first british textile factories bring (select four)