- Rejoinder to Mr. Quigby ow Crank Motion. 65 
ing engine, would equal the least waste in the best rota 
; thus furnishing a case where the work was equal, if 
— roma arises patie a in of coals. But this does 
not happen in any instance. The pum engines alwa 
perform much better than the anne the a esncetn. 
ed in the formation of the steam being of like structure. As 
to the load in the buckets being too light, it is a sheer 
assumption of Mr. Quinby, not warranted by the statement 
of a single fact, and subject to the obvious general objection 
that | have made to the assumption of a waste of coal, which 
is that some of the pumping engines are just as likely to be 
in the same condition, of working with an insufficient load. 
But this is not all, for presuming the Pe a i of the 
mines have a common share of judgement and capacity of 
observation, and being in the constant habit of working their 
engines; experience alone would inevitably teach them very 
nearly the load for a maximum effect, and interested as they 
are in making every possible saving, we may be certain that 
they would take the means to have their engines worked 
with the proper loads to produce it. But there are, in Corn- 
wall even, men of high endowments, familiar with every 
—_ relating to the construction or working of engines, 
striving with each other to produce the greatest effect 
their different machines ; and is it to be supposed that 4 
fact, which would be before their a Madi day, has 
so long u nperceived or neglected 
self — - own statement to he true? ‘His very lier 
confidence ce ia 
be, tie Soke uneet follow as a necessary consequ haste Ag 
doubts the fact of any loss; ‘ doubt Yana applic to 
that, which, if it existed, must inevita oo arene 
Mr. Quinby’ 3 next shift is that wr mption of tails 
js not an accurate measure of the po wer ioheed. A very 
short examination will show us a weight of this objection. 
It is very evident to every one, that in any abe simi- 
larly constructed in all the parts concerned i thes ~ 
steam, the same quantity of coals of like 
porize equal quantities of water, under a like i In 
practiogs the quantity. of water 
fi 
? 
vaporized by one bushel of 
Newcastle coals, is ae. by: Mr. Watt ie the limits: of 
rom eight to twelve cubie-feet, andthe steam thus produced 
'3 found capable of raising, orth Woolts pumping engine, an 
