Defcri prion of 

 the parts, and 

 their organiza- 

 tion. 



lC2 DESCRIPTION OF A .NEW ENGINE 



Hiftory of anew The engine, of which a fe&ion is here given on a fcale of 

 fn^water r by a an ^ ia ^ an mc ^ to a foot, was ere&ed three years ago at the 

 inclofed column. Druid Copper Mine, in the parifh of Illogan, near Truro, in 

 Cornwall. 



It was worked about two years ; but the mine has not 

 proved fufficiently beneficial to encourage the proprietors to 

 go on during the laft twelvemonth. AB reprefents a pipe 

 fix inches in diameter, through which water defcends from 

 the head to the place of its delivery to run off by an adit at S, 

 through a fall of 31 fathom in the whole ; that is to (ay, in a 

 clofe pipe down the Hope of a hill 200 fathoms long, with 26 

 fathoms fall ; then perpendicularly fix fathoms, till it arrives 

 at B, and thence through the engine from B to S two fathoms. 

 At the turn B the water enters into a chamber C, the lower 

 part of which terminates in two brafs cylinders four inches in 

 diameter; in which two plugs, or pi/tons of lead D and E, are 

 capable of moving up and down by their pifton rods, which 

 pafs through a clofe packing above, and are attached to the 

 extremities of a chain leading over, and properly attached to 

 the wheel Q, fo that it cannot ilip. 



The leaden pieces D and E are cait in their places, and 

 have no packing whatever. They move very eafily ; and if 

 at any time they mould become loofe, they may be (pread out 

 by a few blows with a proper initrument, without taking them 

 out of their place. On the fides of the two brafs cylinders, in 

 which D and E move, there are fquare holes communicating 

 towards F and G, w r hich is an horizontal trunk or fquare pipe, 

 four inches wide and three inches deep. All the other pipes 

 G, G and R are fix inches in diameter, except the principal 

 cylinder wherein the pifton H moves ; and this cylimie: ;. 

 ten inches in diameter, and admits a nine foot ftroke, though 

 to accommodate the drawing to our Journal, it is here deli- 

 neated as if the ftroke were only three loot. 



The pifton rod works through a fluffing box above, and is 

 attached to M N, which is the pit-rod, or a perpendicular 

 piece divided into two, fo as to allow its alternate motion up 

 and down and leave a fpace between, without touching the 

 fixed apparatus or great cylinder. The pit-rod is prolonged 

 down into the mine, where it is employed to work the pumps, 

 or if the engine were applied to mill work, or any other ufe, 

 this rod would form the communication of the firft mover. 



KL, 



