394 Mechanic Arts. 



one person, and with much more convenience and 

 expedition than formerly. 



It was before remarked that Steam Engines were 

 scarcely at all known prior to the eighteenth cen- 

 tury. To the honour of inventing and perfecting 

 this kind of machinery the artists of Great-Britain 

 are entitled. The honour particularly due to 

 Messrs. Newcomen, Beighton, and Watt, on 

 this subject, has been acknowledged in a former 

 chapter. The force of Steam has been applied^; 

 during the period under review, to iht turning of 

 mills for almost every purpose; and there is no 

 doubt that the machines moved by this agent are 

 the most powerful ever formed by the art of man.^" 



In the erection of Bridges, modern artists have 

 displayed unprecedented boldness and enterprise. 

 The first bridge constructed of cast iron was 

 produced in the eighteenth century. This was 

 erected over the river Severn, in Shropshire, South- 

 Britain, in 1779, by Mr. A. Darley, an inge- 

 nious iron-master, assisted by the exertions ot 

 Mr. J, Wilkinson, of the same profession. The 

 second iron bridge was constructed on a larger 

 scale, over the same river, in 1796, upon a new 

 plan, by Mr. Tiielford. A third, on a still larger 

 and more daring scale, was built over the river 

 AVear, in Durham, a short time afterw^ards, by 

 Rowland Bltrdon, Esq. To these may be added 

 the zvoockn bridges, of several kinds, and on va- 

 rious new constructions, which have been invented 

 in the course of a few years past, both in Europe 



; One of these engines, as improved by Mr. Watt, and employed for 

 draining the deep mines of Cornwall, works a pump of eighteen inches di- 

 ameter, and upwards of loo fathom, or 600 feet high, at the rate often to 

 twelve strokes, of seven feet long each, in a minute, and with one-fifth 

 part of the fuel that a common engine would take to do the same work. 

 The power of this engine may be more easily comprehended by saying that 

 it can raise a weight equal to 8i,coo lbs. eighty feet high in a minute, 

 which' is equal to the combined action of 200 good horses. See JSotutiie 

 Garden^ AJJHional Nota^ p. 155, Nsw-York edition. 



