The Project Gutenberg eBook, Life of Richard Trevithick, Volume II (of 2), by Francis Trevithick, Illustrated by W. J. Welch This eBook is for the use of anyone anywhere in the United States and most other parts of the world at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org. If you are not located in the United States, you'll have to check the laws of the country where you are located before using this ebook. Title: Life of Richard Trevithick, Volume II (of 2) With an Account of His Inventions Author: Francis Trevithick Release Date: August 19, 2014 [eBook #46634] Language: English Character set encoding: ISO-8859-1 ***START OF THE PROJECT GUTENBERG EBOOK LIFE OF RICHARD TREVITHICK, VOLUME II (OF 2)*** E-text prepared by Chris Curnow and the Online Distributed Proofreading Team (http://www.pgdp.net) from page images generously made available by Internet Archive (https://archive.org) Note: Images of the original pages are available through Internet Archive. See https://archive.org/details/lifeofrichardtre02trevrich LIFE OF RICHARD TREVITHICK, WITH AN ACCOUNT OF HIS INVENTIONS. BY FRANCIS TREVITHICK, C.E. ILLUSTRATED WITH ENGRAVINGS ON WOOD BY W. J. WELCH. VOLUME II. LONDON: E. & F. N. SPON, 48, CHARING CROSS. NEW YORK: 446, BROOME STREET. 1872. LONDON: PRINTED BY WILLIAM CLOWES AND SONS, DUKE STREET, [Pg i] [Pg ii] STAMFORD STREET AND CHARING CROSS. CONTENTS OF VOLUME II. CHAPTER XVII. Various Inventions. Stone-crushing mill, 1804--Portable puffer, 1805--Staffordshire potteries-- Engine for South America--Diversity of steam appliance--Numerous high-pressure engines--West India Dock locomotive-- Engines at Newcastle--Blacklead lubricator--Engines in Wales--Mine engines on wheels, 1804--Engines in London--Engines to be sold in market towns--Blast-furnaces--Aërated steam- boiler--St. Ives Breakwater--Dolcoath blast copper furnace--Davies Gilbert's opinion of the aërated steam-boiler-- Trevithick's advice to a brewer-- Agricultural engines--West India engines-- Thrashing engine--Horizontal engines-- Expansive steam--Cold surface condenser--Air-pump--Expansive cam-- Fire-bars--Comparison with Watt's engine--Stone-boring engine, 1813-- Plymouth Breakwater, reduction in cost-- Locomotive engine, 1813--Stone splitting- -New method of stone boring, 1813-- Screw bit, 1813--Falmouth Harbour-- Exeter Bridge--Engine at Lima--Proposed train from Buenos Ayres to Lima--West India portable engine 1-35 CHAPTER XVIII. Agricultural Engines; Loss of Papers. Sir Christopher Hawkins's thrashing machine, 1812--Report of three wise men- -Cost of horse and steam power--Wheal Liberty engine--Sir John Sinclair and the Board of Agriculture--Cost of engine-- Power of engine--Welsh locomotive-- Trevithick on steam agriculture--West Indies engine--Horse-power--Trevithick on patents--Engines in charge of labourers--Teapot--Detail of agricultural engine--Lord Dedunstanville's thrashing machine--Plymouth Breakwater locomotive--Wheal Prosper engine-- Wheal Alfred engine--Steam-plough-- Cultivation of commons--Combined steam-tormentor, narrower, and shoveller- -Mr. Rendal's thrashing machine--Cost and work performed by thrashing engines- -Their durability--Bridgenorth engine-- Trevithick's drawings light the tires 36-68 CHAPTER XIX. Pole Steam-engine. [Pg iii] Return to Cornwall, 1810--Wheal Prosper pole vacuum engine, 1811--Cylindrical boilers, 1811--Steam pressure, 100 lbs.-- Duty of engine, 40 millions--Expansive working, 1811--Herland high-pressure pole puffer, 1815--Steam pressure, 150 lbs.--Boiler making--Comparison with Watt's engine--Blue-fire--Steam--Patent specification--Steam-ring stuffing box-- Engines in Lima--A 33-inch pole-puffer more powerful than a 72-inch Watt engine--Description of pole engine and boilers--Trevithick's calculation--Trial of Herland engines--Steam-cushion--Power of the pole-engine--Defective workmanship--Sims examines the pole- engine--Opposition from shareholders-- Defective boilers--Challenge to Woolf-- Davies Giddy's opinion--First cost, and cost of working one-third of the Watt engine--Meeting of opposing shareholders--Duty of the high-pressure steam pole puffer-engine, 1816-- Comparison with the Watt engine-- Combined high-pressure pole and cylinder for expansion--Wheal Alfred Watt engine converted to high pressure--Wheal Chance combined engine--Mr. Michael Williams's opinion--Woolf and Trevithick 69-113 CHAPTER XX. The Watt and the Trevithick Engines at Dolcoath. [Pg iv] Early steam-engines--Semicircular boiler, 1775, net power 7 lbs. on the inch--Watt's statement in 1777--Engines in Dolcoath-- Watt's engine, 1778--Watt's engine at Herland, 1798--Trevithick's tubular boiler, 1799--Reconstruction of the Carloose 45- inch, 1799--Gross and net power of engines--Comparison of Newcomen, Watt, and Trevithick engines--Boiler explosion, 1803--Strong rivalry with Watt- -Locomotive at Coalbrookdale, 1803-- Watt's proposed locomotive--Competition in Wales--Numerous high-pressure engines, 1803--Patent difficulty--Watt's opposition, 1804--Government inquiry-- Competitive trials in Wales--Tramway locomotive, 1804--The bet--Opposition because of saving of labour--Worcester engine--West India Docks engine--High- pressure steam condensing engines--One or two cylinders for expansion--Sirhowey boilers--Mr. Homfray's opinion of the Watt opposition--Mr. Whitehead makes engines in Manchester--Cylindrical tubular boiler in Wales for large engines, 1805-- Watt contests at Dolcoath, 1805--Steam- blast--Superiority of high-pressure whim- engines--Proposed boiler for the large pumping engine, 1806--Steam pressure-- The Watt boiler--Comparison of size of fire-place and coal used--Dredger contract--Theory of steam--Trevithick's Dolcoath boiler when applied to the Watt engine, with expansive gear, to save 300l. monthly, 1806--Momentum of pumping engine--Continued tests of high and low pressure whim-engines at Dolcoath--Watt engine put aside, 1806--High-pressure engines ordered, 1806--High-pressure pumping engine for Wheal Abraham, 1806--Disputed patent right--Expansion reduces heat--Boiler for the Watt 63-inch engine, 1806--Cost of Trevithick's boiler-- Advantage of small tubes in boilers--Trinity Board--Watt's steam-cylinder unsuitable for high steam, 1806--Sims' trial of engines--Little fight--Tubular boilers, 1806--High-pressure steam pumping engines, 1818--Reporter of engines-- Application to Government, 1810-- Dolcoath engines and boilers--High steam to the Watt engine--Duty of engines, 1812--Watt's boiler thrown out-- Expansive valve--Dolcoath manager-- Saving by boilers and expansive working, 1812--Lean's reports--Increased duty of the three old Dolcoath engines, 1814--76- inch engine, 1816--80,000l. a year saved- -Durability of engine--Its removal-- Cylindrical boilers--Hornblower and Watt engines--Davies Gilbert's report, 1798-- Lean's report, 1816--Watt's views of expansive working--Watt's steam of 1 or 2 lbs. to the inch--Pole's statement--Engine at Marazion, 1804--Woolf in Cornwall-- Rees' Cyclopædia--'Encyclopædia Britannica'--Application to Parliament-- Wheal Towan--Newcomen and Watt engines--Pompe-à-feu 'La Belle Machine,' Dolcoath 114-194 [Pg v] CHAPTER XXI. Engines for South America. Engines for Lima, 1813--Uville's application to Watt--High-pressure model- -Cerro de Pasco mines--Uville's return in search of Trevithick--Engines ordered-- Pump-work--Modern pumping engines-- Money difficulty--Weight of pieces-- 'Sanspareil' of 1813--Expansive working-- Quartz crusher--Locomotive for South America, 1813--Sketch of winding engine- -Their simplicity of form--Power and cost of engines--Trevarthen and Bull to accompany the engines--A third man recommended--Boilers put together at Cerro de Pasco--Uville's arrest-- Trevithick a shareholder--Vivian's application--Departure of machinery, 1814--Uville's agreement--Invoice of engines sent 195-220 CHAPTER XXII. Peru. Agreement for working the Peruvian mines, 1812--Uville and Watt, 1811-- Uville and Trevithick, 1813--Uville's opinion of Trevithick--Estimated value of the mines--Machinery reached Peru, 1815--Trevithick's departure from Penzance, 1816--Mr. Edmond's statement--Cerro de Pasco mines in 1850- -Report from the Viceroy of Peru, 1816-- Report from the Magisterial Deputation of Yauricocha, 1816--Despatch from the Governor of the Province of Tarma, 1816- -Pumping engines at work--The Viceroy's reply--Report in the 'Lima Gazette,' 1816- -Trevithick's reception at Lima-- Trevithick's report, 1817--Differences between Trevithick and Uville-- Trevithick's thoughtless acts--His visit to the nunnery--The Lord Warden proposed to erect a statue in silver to Trevithick-- Bust of Trevithick in Cornwall-- Quicksilver--Sunk ship--Chili--Copper and silver mine--Departure from Lima-- Cerro de Pasco mines 221-259 CHAPTER XXIII. Costa Rica. Gerard at Punta de Arenas, in the Pacific, in 1822--Nicolas Castro worked a gold mine, 1821--Alverado's ore-grinding machine, 1822--Climate of Costa Rica-- Mines in the Cordillera--Canal from the river Machuca to Quebrada-honda-- Castro's mine--Padre Arias, or the Priest's mine--Trevithick and Gerard's proposal for iron railroads, &c., for the mines of Costa Rica, 1827--New line of road from San Juan, on the Atlantic, to the Costa Rica mines--Serapique River navigable-- Trevithick's diary--A mule track easily constructed--Comparative distance to the mines from the head of the Serapique on the Atlantic, and Punta de Arenas on the Pacific--Trevithick nearly drowned in the Serapique--Nearly starved before reaching San Juan--Performs a surgical operation-- Designed the locomotive between breakfast and dinner--Robert Stephenson and Trevithick at Carthagena--Nearly drowned in the Magdalena--Saved by Mr. Bruce Napier Hall--Trevithick nursed Robert Stephenson 260-275 CHAPTER XXIV. Return to England. Bodmin School, 1827--Cube root-- Trevithick's reception--Saving in Cornish mines--Model gun--Gerard's return, 1827--His meeting Robert Stephenson-- His remarks on Costa Rica--Montelegre's search for a better line of road--Mr. M. Williams's proposal--Change of Ministry, and the gun-carriage--Model of iron packet-ship and engine--Robert Stephenson's remarks on mining-- Trevithick's rejection of purchase-money 276-283 CHAPTER XXV. Gun-carriage--Iron Ships--Hydraulic Crane--Ice Making--Drainage of Holland--Chain-pump--Open-top Cylinder--Hayle Harbour--Patent Rights--Petition to Parliament. Trevithick's description of gun-carriage and iron ship--Select committee--Glasgow iron-ship builders--Trevithick's comparison of gunpowder and steam--Cranes worked by air or water--Artificial cold--Liberality- -Holland--Drainage--Dredging--Zuyder Zee--Hydraulic crane--Dutch pumping engine--Chain-pump--Haarlem Lake-- Rhine--Windmills--Hayle Harbour-- Disputed pole-engine patent right--Petition to Parliament, 1828--Marine boilers-- Steam pressure--Engine duty--Lords of the Treasury refuse the petition--Davies Gilbert's views--Marine compound engine of 1871 284-314 CHAPTER XXVI. Tubular Boiler--Superheating Steam-- Surface Condenser. [Pg vi] Binner Downs engine, 1828--Fires around cylinder and steam-pipes--Saving of coal-- Surface condensation at sea--Superheating tubes--Used steam returned to the boiler, 1828--Holland pumping engine--Woolf at the Consolidated Mines--Laws of steam-- Power of heat from 1 lb. of coal--Loss of heat--Experiments at Binner Downs-- Surface condensation--Partial surface condensation for ships or railways--Effect of superheating--Watt's theory doubted-- Wheal Towan and other engines--Loss of heat--Injection-water--Surface condensation and superheating--Partial condensation engine--Duty of chain pumping engine--Surface condensation by cold water or air--Results of the experiment--Hayle Harbour--Condenser of copper tubes, 1829--Suitability for steam-ships--Proposal to erect at his own expense a marine engine with surface condenser and screw-propeller for the instruction of the Admiralty, 1830.-- Sketch of tubular boiler and surface-air condenser--Screw draught--Preservation of heat in condensing by air--Comptroller of the Navy--Patent of 1831--Boiler within the condenser--Surface condensation by air or water--Safety boiler of concentric tubes--Blowing vessel for air condensation and draught--Tubes for distilling water--Steam pressure-- Expansive working--Robert Stephenson's statement--'Echo' steamboat, 1831-- Bottle-neck boiler--Admiralty--Steam Users' Association--Mr. Alexander Crichton's boiler and surface condenser-- Captain Dick and Captain Andrew-- Captain King and the 'Echo' 315-362 CHAPTER XXVII. Heating Apparatus--Marine Steam- engines--Reform Column. [Pg vii] Ill health, 1830--Hot-house boiler-- Heating rooms--Discharging coal-ships by steam--Hot-water stoves for France-- Patent for heating apparatus, 1831-- Marine portable engines--Boat propeller-- Wheal Towan--Discharging coal by steam at Hayle--Proposal to the Common Council of London--Every vessel to carry a steam-engine--Mr. George Rennie-- Proposal to the Admiralty--Surface condensation--Locomotives supplying their own feed-water--Petition in Trevithick's favour--Davies Gilbert's suggestion--His comparison of the Watt and Trevithick engines--Maudslay on Trevithick's proposals--Patent of 1832--Superheating steam--Cylinder placed in flue from boiler- -Expansive steam--Tubular boiler--Water propulsion--Superheating and surface condensation for locomotives--Detail of engine--Proposal to send steamboats to Buenos Ayres--Waterwitch Company-- Messrs. Hall and Sons--Hall's condenser-- Rennie and the Admiralty--'Syria' steamboat--Compound engines--Watt on high-pressure steam--Trevithick on compound engines--Tubular boiler and variable blast-pipe--Refusal of Trevithick's petition to Government--Ill health--Davies Gilbert's statement to Spring Rice-- Meeting on proposed Reform Column-- Trevithick's description--Means of ascent and descent--Placed before the King-- Death--Funeral--His last letter 363-396 ILLUSTRATIONS TO VOLUME II. PAGE Aërated Steam-boiler 7 Rock Splitting 25 Steam Thrashing Engine 37 Agricultural Machine 58 Wheal Prosper High-pressure Steam Pole-engine 70 Cylindrical High-pressure Steam-boilers 71 Expansive Steam Pole-engine 71 Carn Brea Castle 147 Trevithick's Dolcoath Engine of 1816 168 Trevithick's Dolcoath Boilers of 1811 169 Steam Diagram 185 'La Belle Machine' 190 Carriage-wheels 207 Winding Engines 208 Penzance in Olden Time 228 Market, Jew Street, Penzance 243 Mule Track from Lima to Cerro de Pasco 258 Map of Costa Rica Mines 260 [Pg viii] Gun-carriage 285 Dutch Pumping Engine 298 Mount's Bay 318 Partial Condensation Engine 332 Tubular Boiler and Condenser 339 Bottle-neck Boiler 357 Captain Dick and Captain Andrew 361 Hot-water Room-warmer 364 Patent Heating Apparatus 366 Duck's-Foot Paddle 369 Marine Engine and Boiler 380 Compound Marine Engine 385 Reform Column in Detail 391 General View of Reform Column 393 LIFE OF TREVITHICK. CHAPTER XVII. VARIOUS INVENTIONS. "About 1804 Captain Trevithick put up in Dolcoath Mine a stone-crushing mill, having large cast-iron rollers, for breaking into small pieces the large stones of ore; it was spoken of as the first ever used for such a purpose; the same form of crusher is still used in the mines. It caused a great saving compared with breaking by a hand hammer."[1] "I saw at the Weith Mine in 1805 a portable high-pressure engine, made by Captain Trevithick. "It was called a puffer; the cylinder was in the boiler; the steam about 30 lbs. on the inch above the atmosphere. A wooden shed sheltered the engine and man. "The facility of manufacture and cheapness of those engines caused them to be much used in the mines, and also elsewhere."[2] Mrs. Trevithick, about the time we are speaking of, accompanied her husband through one of the Staffordshire china manufactories. Trevithick said to the manufacturer, "You would grind your clay much better by using my cast- iron rolls and high-pressure steam-engine." The manufacturer begged him to accept a set of china. Mrs. Trevithick was disappointed at hearing her husband say "No! I have only told you what was passing in my mind." Driving rolling-mills was among the early applications of the high-pressure steam-engines; but pulverizing hard rock by the use of iron rollers was a novelty: though his patent of 1802 shows the proposed rolls driven by steam for crushing sugar-canes, yet no one had dreamt, prior to 1804, of economy in crushing stone and clay by such a means. The plan, however, remains in use to this day in many mines, and is frequently spoken of under the name of quartz-crusher. "Mr. Giddy, "Coalbrookdale, September 23rd, 1804. "Sir,—Yours of the 13th this day came to hand. I left Wales about eight weeks since, and put an engine to work in Worcester, of 10-horse power, for driving a pair of grist-stones, and a leather-dressing machine, and another in Staffordshire for winding coals; each of them works exceedingly well. "From Coalbrookdale I went to Liverpool, where a founder had made two of them, which also worked exceedingly well; one other was nearly finished, and three others begun. Some Spanish merchants there saw one of them at work, and said that as soon as they returned to Spain they would send an order for twelve engines, of 12-horse power, for South America. In South America and the Spanish West Indies water is very scarce; in several places there is scarcely water for the inhabitants to drink, therefore there is no water for any engine. By making inquiry, I found that ten mules would roll as much cane in an hour as would produce 250 gallons of cane-juice, which they boil until the water is evaporated, and the sugar produced. "I told them that the engine-boiler might be fed with this juice, and by a cock in the bottom of the boiler [Pg 1] [Pg 2] constantly turning, and by taking a greater or smaller stream from it, they might make the juice as rich as they liked. In this process the juice would be so far on towards sugar, and the fire that worked the engine would cost nothing, because it would have taken the same quantity of fuel under the sugar-pans to evaporate the water, as it would in the engine-boiler. "The steam from the engine might be turned around the outside of the furnace for distilling rum, as the distilleries require but a slow heat. "I think the steam would answer a good purpose around the outside of the pan. "If this method answers, the cost of working the engine would be nothing, and the engine would be then working, as it were, without fire or water. "The Spaniards told me that if this plan answers, they would take a thousand engines for South America and the Spanish West Indies. I shall be very much obliged to you for your opinion on this business. These merchants make a trade of buying up sugar mills and pans, with every other thing they want from England, and exchange them with the Spaniards for sugar. "At Manchester I found two engines had been made and put to work; they worked very well: three more are in building. From there I went to Derbyshire. The great pressure-engine I expect will be at work before the middle of October. A foundry at Chesterfield is building a steam-engine as a sample; two foundries in Manchester are at full work on them, and one in Liverpool. There are six engines nearly finished at Coalbrookdale, and seven in a foundry at Bridgenorth. "I am making drawings for several other foundries. Any number of them would sell. A vast number are now being erected, and no other engine is erected where these are known. The engine for the West India Docks was neglected during my absence from the Dale, but I expect it will be ready to send off in ten days. "In about three weeks I shall be in London to set it up. It will please you very much, for it is a very neat and complete job, and I have no doubt will answer every purpose exceedingly well. At Newcastle I found four engines at work, and four more nearly ready; six of these were for winding coal, one for lifting water, and one for grinding corn. "That grinding corn was an 11-inch cylinder, driving two pair of 5-feet stones 120 rounds per minute; ground 150 winchesters of wheat in twelve hours with 12 cwt. of small coal. It worked exceedingly well, and was a very complete engine, only the stroke was much too short, not more than 2 feet 6 inches, which made very much against the duty. "The other engine that was lifting water had a 5½-inch diameter cylinder, with a 3-feet stroke, drawing 100-gallon barrels, twenty-four every hour, 80 yards, burning 5 cwt. of coal in twenty-four hours. "This work it did with very great ease. I believe you will find this an exceeding good duty for a 5½-inch cylinder engine. "Below I send a copy of Mr. Homfray's and Mr. Wood's letters to me:— "Mr. Homfray's, of the 10th September.—'Our great engine goes on extremely well here, nothing can go better; the piston gives no trouble; it goes about three weeks, and we work it with blacklead and water; the cylinder is as bright as a looking-glass; it uses about 2 lbs. of blacklead in a week; about once in twelve or fifteen hours we put a small quantity of blacklead, mixed with a little water, through the hole in the cylinder screw, and we never use any grease. We rolled last week 140 tons of iron with it, and it will roll as fast with the both pair of rolls, as they can bring to it.' "Mr. Wood's letter, September 12th.—'We are going on, as it is likely we always shall, in the old dog- trot way, puddling and rolling from the beginning of the week till the end of it. Your engine is the favourite engine with every man about the place, and Mr. Homfray says it is the best in the kingdom.' "I have not the smallest doubt but that I can make a piston without any friction or any packing whatever, that needs not to have the cylinder screw taken up once in seven years. It is a very simple plan, and will be perfectly tight; it is by restoring an equilibrium on both sides of the piston. I expect to see you in London soon, and then will give you the plan for inspection before I put it in practice. "I am very much obliged to you for recommending these engines in Cornwall, but you have not stated in what manner they are to be applied; whether to work pumps, or barrels, or both. They may be made both winding and pumping engines at the same time, if so required. "A rotative engine will cost more than an up-and-down-stroke, on account of the expense of the fly- wheel and axle. An engine capable of lifting 180 gallons of water per minute 20 fathoms would cost, when complete and at work, patent right included, about 220l. If it is a rotative engine, with a winding barrel, it will cost 270l. I expect that a 7-inch cylinder would be sufficient for winding at Penberthy Crofts, which might have a Crank on the fly for lifting water in pumps, and a winding barrel on its back. This would cost about 170l.; the erection of them, when on the spot, will cost nothing. You do not say when you intend to be in town. I hope you will be present when the dock-engine is set to work. "The engines first sent to Cornwall, must be from Coalbrookdale; then they will be well executed, but from Wales it would not be so. "You may depend on having a real good engine sent down, with sufficient openings given to the passages. "The engineer from the Dale has been lately in London, and has just returned; he gives a wonderful account of the engines working in London. There are twelve now at work there. They have well established their utility in different parts of the kingdom, and any number would sell. The founders intend to make a great number, of different sizes, and send them to different markets for sale, completely finished, as they stand. "You do not say anything about wheels to the engine for Penberthy Crofts. There are several engines here nearly finished; if they suit in size for Penberthy, one may be sent down in four or five weeks, otherwise it may be two months. "I am, Sir, "Your very humble servant, "Richard Trevithick. "Direct for me at the Talbot Inn, Coalbrookdale." Trevithick worked hard and successfully in making his steam-engines useful, and firmly believed that he could and would make them universal labourers. Even the Spanish merchants, unacquainted with steam, talked of giving an [Pg 3] [Pg 4] [Pg 5] in context order for several engines for South America; and their glowing account of the wide field open to him may have been instrumental to his going to that country by making his engines known there. His proposal to make the sugar- cane convert itself into sugar by the use of his patent high-pressure steam-engine may be more theoretical than practical; but many more unlikely things have come to pass. At that time several of his engines were at work in Wales, Worcester, Staffordshire, Coalbrookdale, Manchester, Derbyshire, Liverpool, Cornwall, and Newcastle-upon-Tyne. Twelve were at work in London, and so familiar were people with them, that founders intended to construct them of different sizes, and send them for sale at the large market or county towns; their cost complete, ready for work, to be 200l., more or less, according to size, with a range of application unlimited. His one letter, casually written sixty-seven years ago, mentions them as grinding corn, dressing leather, winding coal, crushing sugar-cane, prepared to boil sugar, and distil rum; pumping water, rolling iron, railway locomotion, portable steam fire-engine, portable steam-crane, mine engines on wheels; so that it may almost be said he was not too sanguine in hoping to send in 1804 a thousand of his engines to South America, for in those cursory remarks he draws attention to no less than thirty-six high-pressure steam-puffers at work. The Penberthy Croft Mine portable engine could be placed on wheels or otherwise, according to the wish of the purchaser, as though steam locomotion was an every day occurrence in 1804. "Mr. Giddy, "Camborne, January 13th, 1811. "Sir,—From calculating the quantity of blast given to a blast-furnace, I find a considerable quantity more of coal consumed by the same quantity of air in this way, than by the usual way in common engine chimneys. Of course the more cold air admitted to pass through the fire, the more heat carried to the top of the stack. Crenver 63-inch cylinder, double-power, 8-feet stroke, with but one boiler, works five strokes per minute. This gives about 1600 square feet of steam per minute, and burns about 8 tons of coals in twenty-four hours. The stack for this boiler is 3½ feet square, and the draught rises 10 feet per second, and will set white paper in a flame at the top of it in about a minute. Therefore, this chimney delivers 7200 square feet of air per minute, which is four and a half times the quantity of heated air, at nearly four times the temperature of heat that there is of steam produced from the same fire, and delivered to the cylinder. "A blast-furnace that burns 100 tons of coal per week is blown by a 5-feet diameter air-cylinder, 4-feet stroke, ten strokes per minute, double-power, giving about 1600 square feet of air per minute, to consume 100 tons of coal, besides giving a melting heat to 350 tons of ore and limestone. "Crenver engine has 7200 square feet of air to burn 56 tons of coal per week, which is above eight times the quantity of air used by air fire-places to what is used in a blast-furnace, and of course must carry off a great proportion of the heat to the top of the stack, that might be saved if the engine-fire was a blast instead of an air fire. "But suppose the idea to be carried still further, by making an apparatus to condense and take the whole of the heat into the cylinder instead of its passing up the chimney. By having a very small boiler, and a blast-cylinder to blow the whole of the blast into the bottom of the boiler, under a cylinder full of small holes under the water, to make the heated air give all its heat to the water. "The furnace must be made in a tight cast-iron cylinder. Both the fire-door and the hole through which the blast enters must be quite tight, as the pressure will be as strong in the fire-place as in the boiler. The whole of the air driven into the fire-place, with all the steam raised by its passage up through the water in the boiler, must go into the cylinder. There will also be the advantage of the expansion of the air by the heat over and above what it was when taken cold into the blast-cylinder. "From the great quantity of coal burnt in blast-furnaces you will find that a very small blast- cylinder would work a 63-inch cylinder double. If there is as much heat in a square foot of air as in steam of the same temperature, the saving will be beyond all conception; but for my own part I cannot calculate from theory what the advantages will be, if any, and for that reason, before I drop or condemn the idea, I must request you will have the goodness, when you have an hour to spare, to turn your thoughts to this subject, and inform me of your sentiments on it. "Perhaps it is like many other wild fancies that fly through the brain, but I did not like to let it go unnoticed without first getting your opinion. I hope you will excuse me for so often troubling you. "St. Ives plans will be delivered to them on Tuesday, when I expect they will be forwarded to you. "I hear there is a good course of ore in the adit end at Wheat Providence Mine. "A Mr. Sheffield, of Cumberland, writes to Mr. Gould that he has turned idle his air-furnaces, and smelted his ores by a blast near a year since. "His furnace is but 10 feet high and 4 feet diameter, and it melts 28 tons of ore, of from 4 to 5 in the 100 per week, and makes a regel of from 65 to 70 in the 100, and answers beyond what we calculated for them. [Pg 6] [Pg 7] [Pg 8] "Suppose a furnace 20 feet high and 4 feet diameter, it would smelt eight times the quantity of his, which would be near 900 tons per month, or nearly double the quantity raised by any one mine in the country. The expense of the ... would be very trifling. "To-morrow Dolcoath account will be held, when I expect to have orders to begin to erect a furnace on the spot. "This trial of Mr. Sheffield's has put it out of my power to get a patent, and now I do not know how to get paid. "I should be content with 5 per cent. on the profits gained by this plan, and would conduct the business for the mines without salary. Should you chance to fall on the subject with his Lordship, be pleased to mention something about the mode of my payment, as his Lordship is by far the properest person to begin with about my pay, for after his Lordship has agreed to the sum, and Dolcoath Mine the first to try the experiment, I think all the county will give way to what he might propose. But I wish something to be fixed on before all the agents in the mines know how to be smelters themselves, after which I expect no favour, unless first arranged. "I remain, Sir, "Your very humble servant, "Richard Trevithick. How great was the practical insight his genius gave him, and how imperfectly his followers have acted on this advice given sixty years ago! The chimney that at its top would ignite paper, threw to waste four and a half times more heated air than was requisite to supply the quantity of heat which passed through the working cylinder in steam, and at a temperature nearly four times greater than the temperature of the steam. It needs only to observe the burnt appearance of a steamboat funnel of the present day to know how wasteful we still are, or how very ignorant of improved methods of economizing fuel. To prevent this waste of heat up the chimney be proposed to do away with the chimney altogether; the fire-place was to be a close one, having a blast under the fire-bars of a strength sufficient to force the air, heated by its passage through the fire, direct through a small valve into the water in the boiler, by which means all the heat given by ignition would pass into the steam, and his steam-puffer become an aërated steam-engine. From the following it appears that this plan of Trevithick's is now coming into use as something quite new:— "In your last impression, under the head of 'Air and Steam combined, as a Motive Power,' you state 'the invention was described to be that of Mr. Warsop, but we have recently heard that a few years back (1865) the same invention had been protected in an earlier patent than Mr. Warsop's, by Mr. Bell Galloway.'"[3] Trevithick thought of patenting a plan for reducing copper ore by the use of a blast, in preference to the usual air- furnace and chimney, but something similar had been tried by Mr. Gould, and he therefore proposed to erect a blast-furnace in Dolcoath Mine, receiving a portion of the saving of fuel as his remuneration. Such a furnace worked there for many years, until copper smelting was removed from Cornwall to Wales. The plans for a breakwater at St. Ives were for an undertaking that has since been in many hands, but without success, except perhaps for the convenient making of members of Parliament. Some slight progress has been made by engineers and contractors, but vessels are not willingly taken to the port, and ratepayers grumble at unprofitable harbour taxes. "Dear Trevithick, "London, January 20th, 1811. "I have not lost any time in mentioning your wishes respecting a compensation for the plan of smelting copper to Lord Dedunstanville, who intends mentioning the affair in his next letter to Mr. Reynolds. Lord Dedunstanville wishes you extremely well, but it is impossible for him to settle anything apart from the adventurers. "I am very sorry that anyone should have executed the plan of reducing copper ore by a blast-furnace before you had put into practice the idea suggested to me ten years ago. It ascertains, however, that the contrivance will succeed, although you are certainly reduced to ask moderate terms, and I know not what can be more moderate than those you have asked, except that I would recommend some limit as to time. "The plan you suggest for an engine on a new construction is, I fear, very doubtful. "According to the data furnished to me, the air in the blast would be to that in a common fire-place as 6¼ to 1 very nearly, provided their densities were the same; but you have measured one entering the furnace at the common temperature, and the other going to the stack so hot as to set on fire a piece of paper held at the top. Thus the increase of temperature that augments the elasticity of a fluid confined, would expand it in the same degree. It is therefore uncertain from these statements which furnace consumes the greater quantity of air. I apprehend the general principles of an engine worked by hot air, through the medium of a blast, would be as follows:— "Let any quantity of air be driven into a furnace with the pressure of an atmosphere, and let it be there expanded ten times. It should then be taken off ten times as quick, but in that case no power whatever would be produced, so the external atmosphere would balance the internal. Now, let the blast be two atmospheres strong, and let them be expanded ten times, and be taken off ten times as fast, each stroke will be opposed by one, equal in all to ten; subtract two for the blast, there remain eight. "But air so hot would burn every vegetable or animal substance, and such a furnace I suppose could scarcely be kept air-tight. If the heated air is made to act on water, then it becomes a mere question of how much absolute heat is given out by the fuel, and whether that excess is more than sufficient to compensate the burden of the blast; for the water will absorb an immense quantity of heat in changing itself into steam, and thus reduce the force of the air as to make it almost impossible for that addition to add so much power as the blast takes away. "I have, therefore, no hesitation in saying that this plan will certainly not do. Write to me by all means whenever anything strikes you, and you may always depend on having my best advice. [Pg 9] [Pg 10] [Pg 11] [Pg 12] "I am, dear Sir, Ever most truly yours, Davies Giddy." Trevithick saw without apparent reasoning, while his friend's reasonings failed to make plain the full bearing of the questions, and so cramped the position as to make a change of front difficult—an operation in which Trevithick excelled. We learn, however, that in 1801 he suggested a blast in copper-ore furnaces, and in 1811 was on the verge of a discovery that has since revolutionized the iron-smelter's art by the use of hot blast. Wasted heat from a blast-furnace 10 feet high led him to the conclusion that by doubling the height of the furnace, enabling the cold mineral thrown in at the top to take up the heat wasted through the top of the low furnace, seven-eighths of the coal would be saved. His idea of sending blast through the furnace of his steam-boiler to economize heat could have been readily applied to the iron furnace, and we should have had the modern hot-blast iron furnaces. [Rough draft.] "Gentlemen, "Camborne, March 5th, 1812. "Your favour of the 15th February, with a sketch of your brewery, I have received; and from which I find the head of water is 30 feet above the brewery, which makes it difficult to erect the chain and buckets so as to take advantage of the whole height of water; and as the stream is so very small, it will not admit of losing any part of the power. "To erect a machine so high, to engage the whole fall, would be, I fear, more expense than the power you would get would warrant; therefore I would recommend it to be made use of in a cylinder, in the same way as we use falls of water of 200 feet in our Cornish copper mines. We allow one-third loss for friction and leakage in those machines; but your machine being so very small, the loss will exceed that proportion; therefore I cannot promise you above one-half of the real weight and fall to be performed on your machinery, and that must be by a well-executed machine, for a small defect would destroy the value of so trifling a power. "As there is no expansion in water, it will be somewhat difficult to make the machine turn the centres with a fly-wheel, for if the valve shuts a little too early or too late for the turn of the crank over the centre, the fly-wheel's velocity must break something by confining the water between the piston and the bottom of the cylinder, which, after the valve is shut, cannot make its escape, and not having an elastic principle, the piston will strike as dead on the water as on a piece of iron, because, unless the valve is shut by the engine before the stroke is finished, it cannot shut at all. "I know persons who have attempted to put fly-wheels on pressure-engines of this kind, but never yet has one been made to work rotative. I do not see much difficulty in making an engine of this kind to work a crank and fly-wheel, by connecting an air-vessel with the cylinder to receive the pressure and contract and expand and shut the valves, the same as in steam-engines. "A machine on this plan ought to be placed as near the low level as possible. If I furnish you with drawings and directions for the executing of the work yourselves, I shall charge you fifteen guineas for them. If I send the machine finished, the charge will be 50l. "Your objections respecting steam-engines I do not doubt are correct, when executed by persons who do not understand the construction of them. In England some persons privately erected my engine to evade the patent premium, but have severely paid for their saving knowledge by accidents and defects in their engineering ability. I have erected above 100 steam-engines on this principle, but never met with one accident or complaint against them. To prevent mischief from bad castings, or from the fire injuring the surface of cast iron, I make the boilers of wrought iron, and always prove them with a pressure of water, forced in equal to four times the strength of steam intended to be worked with. "Some persons have worked those engines under a pressure above 100 lbs. on the square inch, but in general practice I do not exceed 20 lbs., finding under this pressure the piston will stand six or eight weeks, and the joints remain perfect, and no risk of bursting the boiler, it being made of wrought iron, and proved by pressure before sent off; but cast-iron boilers may, by defects not discernible, and are very apt to break by the water being left low in the boiler, and if heated red hot, exploding without the smallest notice; but wrought-iron boilers, when defective, give way only partially, without injury to anyone. With respect to the erecting and management of the engine, you need not have an engineer, for any common tradesman can do this from the drawings and directions sent with the engine; for, as I before informed you, farmers and their labourers set up and keep in order the thrashing-machine engines without my going on the spot or sending any person to assist them. I never saw a steam-engine rolling malt, therefore cannot judge the quantity the engine would roll, only by a comparison with horse labour, against the consumption of coal, which will be in some cases as about 42 lbs. to one horse; but where great speed is required in the machine, the coal will be less, as steam-engines make more revolutions in a minute than horse mills, therefore the work is done with less friction. "I have several times applied the steam, after it has worked the engine, to boil water and other purposes, with as good effect as if the engine had not been there, therefore the work of the engine will be a clear profit. "You say about a 1-horse engine. The boiler would be so small that it would not be worth applying that steam to any other purpose, as any large quantity of water would be but slowly heated. "I find that it does not answer either the purpose of the vendor or the user of an engine, to make less than a 2-horse power, as the expense on a very small engine is nearly as much as one of the power I use for thrashing, those being only 80l., and a 2-horse is 60l. Respecting the mashing with steam, I never before heard of it, but from the theory of the plan I think it cannot fail to answer a far better purpose than any other that can possibly be applied for extracting the essence of the malt. However, should it not answer your purpose, it is only the loss of the expense of a few yards of 1-inch lead pipe. "In an engine of the size used for thrashing, if the fire is kept brisk, it will boil, by the steam sent into a separate vessel, near 300 gallons of water per hour. "The room required to work in is about 7 feet diameter, and 12 feet high. It would be useless to put you to the expense of drawings, until you have made up your minds on what you intend to have done. "I am,Gentlemen, "Your most obedient humble servant, "Richard Trevithick. [Pg 13] [Pg 14] [Pg 15] "To Robinson and Buchanan, Brewers, "Londonderry, Ireland." Engineers of the present day do not volunteer such general information without charge, or give such a variety of practical mechanism slightly but clearly described, and principles reduced to practice. An endless chain with buckets is a form of water-wheel not then in use. A water-pressure engine for so small a quantity of water, with a fall of about 30 feet, would cause a loss of 50 per cent. from friction and small defects. The non-elastic character of water made it unsuitable for a machine requiring a fly-wheel. Air-vessels should be used to lessen the rigidity of water. Cast-iron boilers dangerous. Wrought-iron boilers to be tested with a water pressure four times as great as the proposed working steam pressure. A steam pressure of 20 lbs. to the inch most suitable for engines in charge of inexperienced persons. The brewers' mash tub to be heated by the waste or surplus steam. [Rough draft.] "Gentlemen, "Camborne, December 5th, 1812. "I have yours of the 20th November. The letter you directed for Truro never came to hand. I find by your letter that you have been trying to put into practice the hints I gave you about the chain and buckets, and that you expect it will answer if properly executed. You are not the first that has picked up my hints, and stuck fast in their execution. I make it a rule never to send a drawing until I have received my fee, and when you remit to me fifteen guineas I will furnish you with proper drawings and directions to enable you to make and erect the machine. "I remain, Gentlemen, "Your very humble servant, "Richard Trevithick. "Robinson and Buchanan, Brewers, "Londonderry." What a pocket encyclopædia of inventions! from which, as by stealth, Robinson and Buchanan selected the least applicable, declining a suitable steam-engine at a very small cost, rather than pay an engineer for his opinion. [Rough draft.] "Sir Charles Hawkins, Bart.,, Camborne, April 26th, 1812. "Sir,—I have received yours of the 7th, respecting the small breakwater at St. Ives. As far as I can judge from a rough calculation, I think it an undertaking likely to pay well; but as you wished me not to mention anything about your intentions, and not receiving your orders to make a minute inquiry and estimate, I cannot answer your letter so fully as I should wish, fearing that giving a random and imperfect statement might be apt to lead you into errors, and also make me look simple. If an engineer were employed to survey and estimate after me, every information in my power is at your service; therefore be pleased to state particularly what information you wish, and I will attend to the business and answer your questions as early as possible. "I have received a letter from Sir John Sinclair requesting correct drawings and statements of the thrashing engine to be forwarded to the President of the Board of Agriculture, which I shall attend to. He also says that he has sent my letter to the Navy Board, in hopes that the experiment of propelling vessels by steam may be tried under its sanction and expense. "Perhaps it might be proper to wait the answer of the Navy Board before writing to Mr. Praed about propelling the canal boats. I am very much obliged to you for writing to Captain Gundry, about the Wheal Friendship engine. I expect to have a portable steam-whim and stamps at work at my own expense in a few days, which will prove for itself its utility; that being the only way to introduce new things. I would be very much obliged to you to say if Mr. Halse is to pay me for my past attendance at St. Ives about the breakwater. Enclosed you have a letter to Sir John Sinclair, unsealed for your inspection, which, if you approve of, please to forward. "I remain, Sir, "Your very humble servant, "Richard Trevithick. Trevithick's skill did not prevent his being reasonably modest, or cause him to be envious of others; neither did his dear-bought experience, that one's own pocket must pay for making public one's own inventions, prevent his again soliciting the assistance of persons of influence, though it does not seem that Mr. Praed helped forward the screw- propeller, or that Sir John Sinclair gave direct help, though he probably made known the high-pressure steam- engine to the marine experimenters on the Clyde. [Rough draft.] "Mr. Rastrick, "Camborne, December 7th, 1812. "Sir,—I have been waiting your answer to my last, and especially that part respecting the West India engine, as I have not nor could not answer their letter to me without first hearing from you; therefore must beg you will be so good as to answer me by return of post on that subject. If they get impatient about the time, and refuse to take the engine, I have no doubt the Plymouth people will take it and several others; but I very much wish to send one to the West Indies, as there is a large field open there for engines of this kind. I have received an order for a thrashing engine for Lord de Dunstanville, of Tehidy; and as I wish those thrashing engines to be known through the country, I intend to take one of the engines ordered for Padstow and send it to Tehidy. One of the Padstow farmers can wait until you make another for him. Therefore I would thank you to send the first finished by ship from Bristol for Portreath or Hayle. Send a drum with everything complete, of which you are a better judge than I. Probably about 3 feet in diameter and 3½ feet long will be sufficient. "There must be a fly-wheel with a notch to carry the rope, and also a small notch-wheel on the drum- axle. I think 6½ feet diameter for the fly, and 9½ inches diameter for the small wheel, will give speed enough to the drum. Mind to cast a lump, or screw on a balance, of about 1 cwt., on one side of the fly-wheel. There must be two stands on the boiler, and a crank-axle, or otherwise a crank-pin, in the [Pg 16] [Pg 17] [Pg 18] fly-wheel, whichever you please; with a shaft 3 feet long with a carriage. "The engine is to stand in a room under the barn, about 7½ feet high, 7 feet wide, and 14 feet long. The fly-wheel will stand across the narrow way of the room. The rope will go up through the floor, and the drum be shifted by a screw, horizontally, on the barn floor, so as to tighten the rope. I shall put down the top of the boiler level with the surface, with an arched way to the fire and ash-pit under ground, to prevent the chance of fire, which the farmers are very much afraid of. I send you a sketch showing how it is to stand. "I do not bind you to the size of the drum or wheels, only the room that the fly-wheel works in is but 7 feet wide. "Now to Mr. Richards' mill. "Query 1st.—The le...