Early experiments with steam James Watt

james eckford lauder: james watt , steam engine: dawn of nineteenth century, 1855



original condenser watt (science museum)

in 1759 watt s friend, john robison, called attention use of steam source of motive power. design of newcomen engine, in use 50 years pumping water mines, had hardly changed first implementation. watt began experiment steam, though had never seen operating steam engine. tried constructing model; failed work satisfactorily, continued experiments , began read subject. came realise importance of latent heat—the thermal energy released or absorbed during constant-temperature process—in understanding engine, which, unknown watt, friend joseph black had discovered years before. understanding of steam engine in primitive state, science of thermodynamics not formalised 100 years.

in 1763, watt asked repair model newcomen engine belonging university. after repair, engine barely worked. after experimentation, watt demonstrated three-quarters of thermal energy of steam being consumed in heating engine cylinder on every cycle. energy wasted because later in cycle cold water injected cylinder condense steam reduce pressure. repeatedly heating , cooling cylinder, engine wasted of thermal energy rather converting mechanical energy.

watt s critical insight, arrived @ in may 1765, cause steam condense in separate chamber apart piston, , maintain temperature of cylinder @ same temperature injected steam surrounding steam jacket. little energy absorbed cylinder on each cycle, making more available perform useful work. watt had working model later same year.

the ruin of watt s cottage workshop @ kinneil house



cylinder fragment of watt s first operational engine @ carron works, falkirk

despite potentially workable design, there still substantial difficulties in constructing full-scale engine. required more capital, of came black. more substantial backing came john roebuck, founder of celebrated carron iron works near falkirk, whom formed partnership. roebuck lived @ kinneil house in bo ness, during time watt worked @ perfecting steam engine in cottage adjacent house. shell of cottage, , large part of 1 of projects, still exist rear.

the principal difficulty in machining piston , cylinder. iron workers of day more blacksmiths modern machinists, , unable produce components sufficient precision. capital spent in pursuing patent on watt s invention. strapped resources, watt forced take employment—first surveyor, civil engineer—for 8 years.

roebuck went bankrupt, , matthew boulton, owned soho manufactory works near birmingham, acquired patent rights. extension of patent 1800 obtained in 1775.

through boulton, watt had access of best iron workers in world. difficulty of manufacture of large cylinder tightly fitting piston solved john wilkinson, had developed precision boring techniques cannon making @ bersham, near wrexham, north wales. watt , boulton formed hugely successful partnership (boulton , watt) lasted next twenty-five years.