a. Se Mr. Genet’s Reply to Dr. Jones. 
“ Before describing his newly contrived propelling ma- 
ehinery, Mr. Genet gives some information relative to the 
steam engine, for the purpose of running a parallel between 
it and his newly discovered power. In doing this, he fur- 
nishes intelligence respecting the derivation of force in the 
steam engine, which is new to us, although we have con- 
structed and used this instrument as well as studied and _ex- 
plained its operation. _ We are told by him, that Mr. Watt 
has availed himself of the downward force of the piston and 
weight of the steam engine, and that the available force as 
created by the falling of the weight and piston into a partial 
and momentary vacuum, and that its power is determined by 
the incumbent weight and by the atmospheric presure. Our 
own conclusions upon the subject were so unlike those of Mr. 
Genet, (called by Doctor Pascalis a philosopher of no com- 
mon stamp,) that we had believed, and even publicly taught, 
that the weight of the piston and of the other moving parts of 
the engine served only to abstract from its power, and that, 
provided they had the necessary degree of stability, the light- 
er they could be made, the better they would answer in prac- 
tice. Instead of supposing that the pressure of the atmos- 
phere was necessary to the action of Mr. Watts’ engine, we 
had taught that its structure might be simplified, and that its 
action we erful, could it be worked in vacuo. 
Here is a great discrepancy, either we or the uncommon phi-- 
losopher, ther with his encomiast, must be in the wrong, 
and need in sober truth to study again our experimental and 
mechanical philosophy. We are givinga fair, candid and 
_ungarbled statement of the doctrines taught by Mr. Genet, 
and let qualified judges decide between us. 
** The following questions, with their answer, are from page 
61, of Mr. Genet’s Memorial. How does the steam engine 
perform that vperation? how does it create that vis motrix, 
— force, which is the mechanical life of the ma- 
chine? By the alternate increase and decrease of tempera- 
ture which produces in the cylinder two kinds of jlhud, the 
means of which the 
