10 REPORT 1888. 



applied, and tlie ' fire ' engine, as it was first called, the ' steam ' engine, 

 as it was re-named, a form of ' lieat ' engine, as we now know it to be, 

 was invented. 



Think of the early days of the steam-engine — the pre- Watt days. The 

 days of Papin, Savory, Newcomen, Smeaton ! Great effects were produced, 

 no doubt, as compared with no fire engine at all ; effects so very marked as 

 to extort from the French writer, Belidor, the tribute of admiration he paid 

 to the ' fire ' engine erected at the Fresnes Colliery by English engineers. 

 A similar engine worked the pumps in York Place (now the Adelphi) for 

 the supply of water to portions of London. We have in his work one of 

 the very clearest accounts, illustrated by the best engravings (absolute 

 working di-awings), of the engine which had excited his admiration. 

 These drawings show the open-topped cylinder, with condensation taking 

 place below the piston, but with the valves worked automatically. 



It need hardly be said that, noteworthy as such a machine was, as 

 compared with animal power, or with wind or water motors, it was of 

 necessity a most wasteful instrument as regards fuel. It is difficult to 

 conceive in these days how, for years, it could have been endured that 

 at each stroke of the engine the chamber that was to receive the steam 

 at the next stroke was carefully cooled down beforehand by a water 

 injection. 



Watt, as we know, was the first to perceive, or, at all events, to cure, 

 this fundamental error which existed prior to his time in the 'fire' engine. 

 To him we owe condensation in a separate vessel, the doing away with 

 the open-topped cylinder, and the making the engine double-acting ; the 

 parallel motion ; the governor ; and the engine indicator, by which we 

 have depicted for us the way in which the work is being performed 

 within the cylinder. To Watt, also, we owe that great source of economic 

 working — the knowledge of the expansive force of steam ; and to his 

 prescience we owe the steam jacket, without which expansion, beyond, 

 cei'tain limits, is practically worthless. I have said ' prescience ' — fore- 

 knowledge — but I feel inclined to say that, in this case, prescience may 

 be rendered ' pre-Science,' for I think that Watt /eZi the utility of the 

 steam jacket, without being able to say on what ground that utility was 

 based. 



I have already spoken in laudatory terms of Tredgold, as being one ol 

 the earliest of our scientific engineering writers, but, as regards the ques- 

 tion of steam jacketing. Watt's prescience was better than Tredgold's 

 science, for the latter condemns the steam jacket, as being a means 

 whereby the cooling surfaces are enlarged, and whereby, therefore, 

 the condensation is increased. 



I think it is not too much to say, that engineers who, since Watt's 

 days, have produced machines of such marvellous power — and, compared 

 with the engines of Watt's days, of so gi-eat economy — have, so far as 

 principles are concerned, gone upon those laid down by Watt. Details 



