378, 
Steam Eyigbie. 
matters, being injected, each stroke, upon the fire ; Si^ 
that all the heat generated by the united combustion may 
operate without waste ; perhaps even a slight sprink» 
ling of water, either upon, or round the sides of the fire, 
might answer the purpose. It scarcely need be observed^ 
that a tube connected with a small forcing pump are the 
only things required for producing these effectSo, 
I remain, Sir, 
Your obedient servant, 
GEORGE CAYLEY. 
(18 Nicholson* s Journal^ p, 260.) 
Summary oj the rise atid progress Steam En=> 
CINE. By the Editor,—! have now given all the in- 
formation I deem important, on the iron manufacture^ 
and the steam engine. The references I have furnish^ 
ed, will enable the reader to supply the slight deficien- 
cies of information, as they comprise every publica*^ 
tion of any character upon the subjects discussed. 
The summary of the improvements gradually introduc- 
ed in the theory and practice of the steam engine, and 
inserted in No. 2 of this volume, p. 217, was printed 
during my absence in Philadelphia ; and unless the errata 
be corrected, will not in some places be intelligible : for 
this reason, I chuse to repeat that summary, with a few 
additional remarks. 
I, It does not appear that the theory of the steam en- 
gine was ever clearly suggested until the Marquis of 
Worcester's Century of Inventions in 1663. An old his- 
toriaiiy I do not know who, writes concerning Pope Silves- 
ter (Silvester 2d) thus : Fecit arte mechanica, orologium, 
et organa hydraulica, ubi, mirum in modum, per aqu^e 
calcfactas violentiam, implet ventus emergens concavita- 
tern bai'bati, et permulti foratiles tractus aerese fistulse mo- 
di ilatos clamores emittiint 1 Athenaeum, 136. I wish 
