JAMES WATT DELUSION

Greymouth Evening Star, 25 February 1928, Page 2

JAMES WATT DELUSION

CHILDREN’S LECTURE. LONDON, January 1. A further lecture of the juvenile series which for 101 years have been given 1 every year in the Christma‘B holidays by well-known men of science at the Royal Institution in Albemarle Street, took place yesterday afternoon, when Prof. E. N. da C. Andrade, D.Sc., took as the subject of a fascinating talk “Engines.” - ■ ’ “A steam engine is a machine for changing the heat of the fuel into work,” he said, introducing his subject. Then he proceeded to discuss, in the simplest possible terms, the further 'inferences, incidentally shattering some well-grounded ideas as to AVatt’s discovery of the steam-engine. “Steam,” went on the Professor, “is only an intermediary, and has no particular virtue in itself. If the whole world was all at one temperature, and that temperature above the boilingpoint of water, we should have plenty of steam, but, however hardy we were, we could not make a steam-engine work unless we could find somewhere a colder spot. ’.

“In any case, steam is by no means the only substance which can be used to work a steam engine. , We could use the vapour of any liquid, as alcohol or ether vapour; in fact', one can. work a toy engine by putting the methylated spirit inside the boiler, and the boiling water outside'. “Practical engines were once made which worked entirely by hot air, but they were enormously bulky. With four cylinders, each 14 feet in diamet-, er, the hot-air engine developed only 300 horse power. In practice, water (and water vapour, called steam), is by far the most convenient substance to use in any engine with a boiler, but it is only convenient, not indispensable. The ‘power of steam’ is a misnomer. “It is often believed that James Watt invented the steam engine, but this is z quite untrue. More than 30 years before Watt was born, both Savery and Newcomen constructed' steam engines which were actually used for pumping. Savery’s engine sucked up the water into a vessel by the- condensation of -‘steam, and then drove the water up from this vessel by the pressgure of steam. Newcomen’s engine had a cylinder and piston, and worked by causing a vacuum under the piston, which was driven down by atmospheric pressure. “The old story that Watt was led to invent the steam engine by playing with a tea kettle has no foundation, for what actually happened was that Watt, who was practising as a instrumet maker, was asked to repair a model of a Newcomen engine.

“In investigating the causes which prevented the model working he was leu to seek for a better design, and ultimately invented the separate condenser—the essential advance which made the steam engine an economic source of power. On account of constructional difficulties he used only low-pressure steam, but every economical engine oL to-day, reciprocating or turbine, ends up with an engine on the Watt system, in which the steam having been expanded to low pressure in oher parts of the engine, does work by virtue of the partial vacuum created by a condenser.

“If Watt did not, correctly speaking, invent the steam engine he, nevertheless/ converted it from a clumsy and unreliable contrivance, used solely for pumping, into the finished machine, using less than a quarter of the coal consumed by its predecessors, which transformed the face of industry, and placed England ahead of all her rivals as a manufacturing country at the beginning of the nineteenth century. “Nearly every feature of an efficient modern reciprocating engine is to be found in Watt’s later designs. Watt’s governor, with the rotating balls, is to be found in a variety of forms on engines of all kinds, from the gas engine to the gramophone motor. “The finger of Watt governs the speed and smooth playing of the record of the latest piece of daiice music, which may commend his memory to many for whom his engineeringachievements have no appeal.”