O4 Rejoinder to Mr. Quinby on Crank Motion. 
iribute the loss to the crank, any more than to the fly 
_ the connecting rod, or any other, the most insignifi- 
cant part concerned in the motion. ‘The loss. was said to 
belong, not to engines of any peculiar structure, but was ex- 
tended to all the met in ‘* common tice ;”’ thus in- 
cluding engines in which the rotation is produced by the 
sun and planet wheels, and which consequently has no 
crank about it, as well as those in which a crank is used, 
The fact was rested on Leans’ reports, in shel it is stated 
that taking an average of a vast number of the engines used 
in Cornwall, those which raise their load directly by the 
danagh sien mass es sg in which it no up a 
continuous rotary motion; the engines being alike in other re- 
spects, except indeed in size, it being declared that they were 
of the peculiar construction of Watt or Woolf. It is true thet 
in the particular cases stated the force was transferred 
pes 9 te crank, yet this being in any eeiee merely an 
arm of a lever, and consequently on capable of i 
force, ees sometime ‘before Me ie 
a fact 
Quinby’s * demonstration of the crank problem,” namely, 
in the age of Archimedes; such general terms were used as 
indicated the Joss under the codditions i in which it happened, 
without fixing it to any mere instrument by which the 
change of motion was produced. 
In my answer to Mr. Quinby, J disclaimed attributing the 
loss in question to any mechanical agent, and it seems 
Mr. Quinby cannot conceive to what I did attribute it. 1 
can give him no aid in his dilemma, as I professed in \the 
oa that | would not undertake to account for it. - 
r. Quinby has discovered, after doubting the fact of 
in question, circumstances which to him satisfac- 
tasly zecount for it. These are “first the injudicious or 
wasteful application of the coal consumed ; and secondly. the 
want of a constant and sufficient load in the buckets during 
the time the engine is in action.” It seems to me very 
clear ae a wasteful application of coals en not belong 
exclusively to the engines, but that the pumping en- 
gines would f gould oullen:te the — . That it would, at 
least in some solitary instances of the numerous ones 
happen that the greatest waste of coals in the worst pemp- 
