THE STEAM-ENGINE. 399 



THE STEAM-ENGINE. 



(FIRST LECTURE.) 



THAT the history of the invention of a piece of mechanism, and the de- 

 scription of its structure, operation, and uses, should be capable of being ren- 

 dered a subject-matter destined not alone for the instruction of engineers or 

 machinists, but for the information and amusement of the public in general, is 

 a statement which at no very remote period would have been deemed extrava- 

 gant and incredible. 



Advanced as we are in the art of rendering knowledge popular, and culti- 

 vated as the public taste is in the appreciation of the expedients by which 

 science ministers to the uses of life, there is still perhaps but one machine of 

 which such a proposition can be truly predicated : it is needless to say that 

 that machine is the STEAM-ENGINE. There are many circumstances attending 

 this extraordinary piece of mechanism which impart to it an interest so uni- 

 versally felt. Whether we regard the details of its structure and operation, 

 the physical principles which it calls into play, and the beautiful contrivances 

 by which these physical principles are rendered available : or, passing over 

 these means, we direct our attention to the ends which they attain, we are 

 equally filled with astonishment and admiration. The history of the steam- 

 engine offers to our notice a series of contrivances which, for exquisite and 

 refined ingenuity, stand without any parallel in the annals of mechanical sci- 

 ence. These admirable inventions, unlike other results of scientific inquiry, 

 have also this peculiarity, that, to understand their excellence and to perceive 

 their beauty, no previous or subsidiary knowledge is necessary, save what may 

 be imparted with facility and clearness in the progress of the explanation and 

 development of the machine itself. A simple and clear exposition, divested 

 of needless technicalities, and aided by well-selected diagrams, is all that is 

 necessary to render the construction and operation of the steam-engine, in all 

 its forms, intelligible to persons of plain understanding and moderate informa- 

 tion. 



