OF CORNWALL. IyI 
by a pulley fixed perpendicularly over the opening of the fhaft, winds 
horizontally : this axis has a tranfverfe beam infix’d, at the end 
of which two horfes fattened go their rounds, and draw more or 
lefs according to the number of circumvolutions in any given time, 
the largenefs of the barrels, and the depth it is to draw. This is 
an engine which can only work in a perpendicular fhaft, if the 
lode underlies confiderably it cannot be ufed. 
Another water-engine which the Cornifh ufe is the rag and chain ; Rag and 
it confifts of an iron chain with knobs of cloth (fenc’d and ftif- chain - 
fen’d with leather) betwixt two and three feet afunder ; the chain 
is turned round by a wheel of two or three feet diameter, fur- 
nifii d with iron fpikes which inclofe and keep fteady the chain, fo 
that it may rife through a wooden pump of about fix or eight inches 
bore, and twelve or fifteen feet long, and by means of the leather 
knobs bring up with it a ftream of water anfwerable to the diameter 
of the pump, and in quantity according to the circumvolutions of 
the wheel in any given time. This engine is worked ufually by 
hand, but where plenty of water can be had, as in St. Auftel 
moor, much more effectually and frugally by fmall water-wheels. 
Several of thefe pumps may be placed parallel upon different ftages 
of the mine, as at pd, pj pg , , p h, Fig. i. PI. XVIII. 
Other pumps they have alfo, as the hand-pump, and the force- 
pump, which like the rag and chain will do well for fmall depths 
and little water, and are neceflary in all Jumps n and the firft link- 
ings into the lode, before the Hopes can proceed. 
More effectual is the water-wheel and bobs, an engine whofe Water-wheel 
power is anfwerable to the diameter of the wheel, and the length and bobs - 
of the bobs fattened to it’s axis by large iron cranks ; a perpendi- 
cular rod of timber to each end of the bobs, works a pifton in a 
wooden, or (which is far better) a brafs hollow cylinder, and the 
quantity of water exhaufted will be in proportion to the bore of the 
cylinder, and the number of times which the pifton moves up and 
down in any given fpace. 
This is an engine very eligible where a fufficient quantity of 
water may be procured, but in fumrner, our fuperficial water in 
Cornwall (where we have few great rivers, and our brooks have no 
long courfe, and the mines are generally on high ground) fails 
much ; fo that many of thefe engines cannot work from May or 
June to October ; a great hindrance at that feafon of the year 
when men can labour longer and with more fpirit than during the 
other months. 
" Pits made in the bottom of the mine for the 
Workings. 
water, or for trying in depth beyond the general 
This 
