Sleam-E?igines in Cornwall. SS3 



for at this moment we are all driven to our wits end to find era- 

 ployment for the poor; and were our mines thrown idle, it is im- 

 possible to anticipate the result. 



** As to danger from engines employing steam of high pres- 

 «iire, none who are competent to give an opinion on the sub- 

 ject, — and none else have a right to do so, — will so far commit 

 themselves as to say that there can be any in working steam of 

 from 35 to 45 pounds pressure on the square inch in the boiler— 

 which is the ratio at which Woolf's engines are worked — pro- 

 vided safety valves be employed, and the construction and ma- 

 terials be of a proper quality. But in fact, this applies also to 

 the common engine — nav, to every machine of high power em- 

 ployed by man. 



■*' As to the common engine being less dangerous than those 

 employing- steam of higher temperature, the idea is quite gromid- 

 less ; for those wh.o make them proportion the strength and 

 substance of their materials accordinglv, — nor do they ever give 

 their boiler the same strength for a pressure of six or seven pounds 

 which they would for a pressure of forty. In point of fact, I have 

 known several instances of accidents in consequence of the boilers 

 of common engines giving way, — I mean such accidents as have 

 caused the loss of lives, — but we have had none of this kind from 

 Woolf's boilers. By the bursting of a common wrought-iron 

 boiler at Poldory mine, three men were killed and three badly 

 scalded: at Cliasewater, two horses were killed by the explosion 

 of the boiler, though at work in a diiferent building from the 

 boiler house. There was also a serious accident at Crenver from 

 one of the common boilers, which caused the loss of several 

 lives. I could name several other accidents of this kind; and 

 therefore I cannot but reprobate the idea of any interference 

 which would compel us to employ these engines or boilers in 

 picfercuce to others. — Dear sir, 



" Yours sincerely, 



'' Wm. DavY;. 



" P. S. Some gentlemen will set off to-morrow for London^, 

 to attend to this business." 



As several steam engines, besides those to which Mr. Woolf's 

 name is attached in .Messrs. Lean's monthly Report, appear to be 

 doing considerably more duty tlian the common engines have 

 been supposed capable of performing, a correspondent requests 

 that Messrs. Lean will, at the bottom of their montidy Report, or 

 through the medium of The Philosophical Magazine, state the 

 cause or causes of this improvement. Has the increased work 

 been produced by employing steam of iiigh temperature, suffered 

 to expand in the working cylinder, and then condensed, on the 



kadin^ 



