PART 1 1 As in the Case of Papin's Model, and the Engine Which
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Notes PART 1 1 As in the case of Papin's model, and the engine which introduced James Watt to steam power at Glasgow University. 2 Indeed, the low-pressure engine flourished for half a century after the high pressure engine "arrived". 3 Each cylinder with its mechanism was commonly described as a separate " engine" by early steam carriage constructors. 4 A considerable investment. In 1785 a single 4 pounder field artillery piece cost only 250-300 francs to manufacture. A franc at both dates had the same value as one livre. 5 It is possible that the average speed required was that expected of draught animals towing heavy artillery on a road. This is supported by a letter from the Musee de l'Armee, Paris, 5 September 1974. Experiments conducted on the London Holyhead road in 1830 by John Macneil, the road's assistant engineer, as described in evidence to the 1831 House of Commons Select Committee on Steam Carriages, showed that a laden 6-horse wagon with an all-up weight of 4t tons (10,080 lbs), comparable with the weight of the Cugnot tractor with a 5000-lb load,, averaged 2!-3 m.p.h.- 4 k.p.h. or a little over. 6 In Robert Stuart, Historical and Descriptive Anecdotes of Steam Engines, ii, 208-9, published in 1829, appears the earliest traceable description in English of Cugnot' s work. 7 The idea may have derived from toll bridges, which had existed since the Middle Ages. 8 Malachy Postlethwayt, Universal Dictionary of Trade and Commerce (1751) 616. 9 W. Albert, The Turnpike Road System in England and Wales, 189. 10 Proof that the low-pressure engine at its best was no longer always Newcomen's lethargic monster is provided by the success of the first working steamboats. Those of the Marquis Jouffroy d'Abbans in 1783, of John Fitch in 1787, and of Patrick Miller in 1788 all had condensing engines. See Marquis Achille de Jouffroy d' Abbans, Memoitr, read to Academie des Sciences, 1839. 11 The cylinder of the oil-fired, high-pressure double-acting engine was recessed into the boiler to keep it hot. Drive was by crankshaft. Double action was normal on road steamers, since it was not only efficient, but also improved smoothness and starting torque. 12 A basically similar specification to that attributed to Papin's model of nearly a century earlier. Other reasons why Symington may have dropped the project could have been the realisation that a condensing engine lacked the power-to-weight ratio needed to propel a full-scale road steamer, and that it would, in any case, have been in violation of Watt's patents. 13 Ironically, Watt's determination and success in protecting his low-pressure and high-pressure patents brought about a revolution in the judicial approach to patents in Britain. Until the eighteenth century, the law gave too much protection 157 158 A New Machine 1769-1842 to the patentee and not enough encouragement to innovators. The 1624 Statute of Monopolies had, inter alia, confirmed the Crown's right to grant letters patent in new inventions for 14 years. If, through no fault of his own, the patentee had not reaped his reward in that period, the patent could be extended by Act of Parliament. Watt took advantage of this. A patent could be granted in the first instance without a full specification, which had to be submitted within six months. In practice, patents could be vague, all-embracing and still valid. By Watt's time, however, the legal requirements were being tightened up. In Lord Mansfield's judgement in 1778, a patent was declared voidable on the grounds of insufficient specification. From the Watt litigation against infringers, which was frequent and well publicised, arose the recognition that fresh patents could be granted for improvements to a known machine, such as the steam engine, and even for ideas or principles, so long as the specification showed that they had been developed far enough to be practical in an industrial or commercial application. It would no longer be possible for one man to stifle progress with a "blanket" patent whose terminology covered every possible development regardless of the likelihood of its working, or getting beyond the paper stage. Watt's was the first patent applicable to steam carriages. Only two more fol lowed between 1784 and 1802. There is, comparatively speaking, a rash of railway locomotive patents between 1811 and 1815, but no more road steamer patents until 1821. Between then and the end of 1830, no fewer than 23 were lodged. This pattern faithfully reflects the changing conditions facing the road steamer - when the auspices become favourable, and not before, the patents multiplied. 14 Francis Trevithick, Life of Richard Trevithick, i, 160-2. 15 New in execution but not in theory; the idea was incorporated in Fourness and Ashworth's patent of 1788, as was recessing the cylinder into the boiler, and crankshaft drive. 16 Watt's steam carriage patent of 1784 had specified change-speed gears. 17 According to a letter in the Mining journal (2 Oct. 1858) Captain Andrew Vivian, one ofTrevithick's partners, recalled in old age how cab drivers and omnibus men had pelted the carriage with cabbage stumps, rotten onions and eggs. This account is suspect, since there were no London omnibuses as such until1829. The account suggests, much more clearly, an encounter of the sort common when the buses and coaches of Hancock and others were running in London 30 years later. 18 London's population almost doubled between 1780 and 1820, inevitably leading to traffic congestion and road wear. Albert, op. cit., 65. 19 When a machine was a novelty and made few public appearances, this was usual. Britain's pioneer "motorists" from the 1820s onwards were regarded with a mixture of amazement, condescension and amusement. Serious attention, and hostility, came only with an increase in numbers, and the clear likelihood that they were going to make themselves felt. 20 George Granville Leveson-Gower, second Marquess of Stafford and later first Duke of Sutherland, is best know to history as an "improving landlord" associated with the notorious Highland Clearances. He built 450 miles of Highland roads at his own expense, between 1812 and his death in 1833, and, like his grandson, took a strong interest in modern technology. Britain's biggest landowner and richest man- Greville' s "leviathan of wealth" -he held a 20 per cent interest in the Liverpool and Manchester Railway, and was the majority shareholder in the Liverpool-Birmingham Canal. 21 A generation later, it was estimated that the resistance to carriage wheels even of a Notes 159 good road was 12 times that of railway track, all other things being equal. See N.W. Cundy, Inland Transit (1833) 65. 22 As late as 1833, it was difficult to find even a tilt hammer in London. See Francis Maceroni, A Few Facts Concerning Elementary Locomotion (1834) 22. 23 Industry on a scale to encourage steam, as existed in Britain, had not yet come to the United States, which was still basically a nation of farmers and merchants. The American colonies had not seen their first Newcomen engine until1753. 24 G. and D. Bathe, Oliver Evans: A Chronicle of Early American Engineering, 109-11. Evans referred to his creation as "a heavy flat-bottomed boat", and as "a machine for clearing docks". Its Greek name, Orukter Amphibolos, meant "amphibious digger". See also Mechanics' Magazine (25 Sept. 1830) 73. 25 F . Trevithick, op. cit., i, 138. Trevithick envisaged using treads of one sort or another, but nothing more protruberant. 26 Walter Hancock, A Narrative Of Twelve Years' Experiments, 18. Hancock does not clearly specify "legs", but seems to mean some such device. 27 Alternatively, the foundations might be of rubble, and if stones were not available for the surface, gravel might be substituted. 28 Prematurely, William Blakey patented a water-tube boiler in 1766. The type could get nowhere in Britain until the Watt patents expired. Dallery took out a patent for a water-tube boiler in 1803, though he is reported to have used it 23 years earlier. In Britain in the same year of 1803, the American John Stevens issued a similar patent for a boiler with a large number of small-diameter tubes; so, too, did Arthur Woolf. Woolf's boiler was supplied with his compound engines, so by 1820 the type was known. 29 Possibly this was the vehicle built by "an ingenious cotton spinner of Ardwick" for goods or passengers; it was said to be capable of 9-10 m.p.h. See Gentleman's Magazine (Nov. 1821) 452; from Manchester Guardian. 30 Mechanics' Magazine (3 June 1826) 79. The ignition of coal gas inside the cylinders created a vacuum. This drove the pistons, not the force of the explosion, as in the modern motor vehicle. Brown worked a gas-engined boat on the Thames in January 1827. The Brown carriage may have reappeared in September 1828, when a gas vacuum vehicle was reported proceeding along the Hammersmith road at 7 m.p.h. 31 The major design problems affecting both rail and road were set out clearly, if wordily, by the London journal of Arts and Sciences in February 1826 (no. 65, 142). Boilers were too heavy and cumbersome, or else too small in generating capacity. The power produced, on its way to rail or road, was either dissipated by inefficient mechanisms or used up in wasteful friction. 32 Observations on Railways with Locomotive High-Pressure Steam Engines (Mar. 1825).