Rejoinder to Mr. Quinby on Crank Motion. 97 
true and whole force, leaving friction out of the qneslivs, 
with which the piston moves, he. declares it equal to the 
whole elastic force of the steam acting upon the piston... 
ies Quinby next “ takes the liberty to state thatthere is 
o Messrs. Leans’ reports oné. word that justifies, or-even 
— admissible, the assertion that there is.in the. steam- 
engine a loss of power in changing the direction of its action 
from rectilinear to rotary, by the methods in common prac-' 
tice! In Tilloch’s Philosophical Magazine we have. the 
whale series of reports on the performance of the engines 
at the mines in Cornwall, by Messrs T. and J. Lean, 
pre a August 1811, and ending November 1818; and 
in these reports the case noticed by the writer of the article 
Stcamengine,, Hae? CY¥clopedia, 1 is not epboned,", 4 
looks like something quite decisive of the. question ;_ but 
unfortunately for. its presi upon. the case, it. is, not true, 
Tillooh’s Philosophical Magazine does not contain the whole 
series of repo.ts on the performance of the Susinek Aas 
the mines in Cornwall. . The S azine 
are professedly nothing more than. extracts from ae 
reports. No comment seems necessary on this statement. 
The writer in the Encyclopedia states the cases, as formerly. 
quoted by me, with all the circumstances, and declares 
them to be taken from Leaus’reports. Mr. Quinby charges 
him,.or. me, or both of us, with falsehood almost in.so many 
words, because the same facts are not A ipl ina SAE 
sci eat presence, irom, the same peapariay me age nr 
rbeuerr ge ete aie eae - ans 
+ “As. corrubesstive of ie teeth of the siatement made fr om Lean 
reports, that the rotary motion is tained without loss of force, I 
may are ae the report ¢ of the | cotamitine of the House of Commons . 
made al the follow- 
dingy pastaiges: re: pian remer ser simsesaapaaates 
nate motion of the piston into the rotary motion Sof thepadilen.” set 
emer eeviion might be brought of Deans” upon m this ae but thou 
_answerab 
sli & necessary . pursue the subject. 
‘Regarding t ral question of loss, some individual have 
doubt “believed, vei absu finds some ao that the. eine 
rdity 
“ occasioned a coset soaat® » but it is by no e, as Mr. Quin- 
- —— stated one that “all the one a that have b om made ‘to apply 
of the steam «directly to , or to construct 
preteen Sa temernbiee inter Sittin and for the tingle purpose 
of obyiating the reat loss of power which different individuals: 
have ieponalll socduenle from the application of the era ” Indeed F 
13 ‘ 
Vou X.—No. 1. 
