176 BOOK VI. 



much water, to drain it by the rag and chain pump or to bring it up in 

 water-bags. 



Enough, then, of the first sort of pumps. I wiU now explain the other, 

 that is the pump which draws, by means of pistons, water which has been 

 raised by suction. Of these there are seven varieties, which though they 

 differ from one another in structure, nevertheless confer the same benefits 

 upon miners, though some to a greater degree than others. The first pump 

 is made as follows. Over the sump is placed a flooring, through which a 

 pipe — or two lengths of pipe, one of which is joined into the other — are let 

 down to the bottom 01 the sump ; they are fastened with pointed iron clamps 

 driven in straight on both sides, so that the pipes may remain fixed. The 

 lower end of the lower pipe is enclosed in a trunk two feet deep ; this trunk, 

 hollow like the pipe, stands at the bottom of the sump, but the lower opening 

 of it is blocked with, a round piece of wood ; the trunk has perforations 

 round about, through which water flows into it. If there is one length of 

 pipe, then in the upper part of the trunk which has been hollowed out there is 

 enclosed a box of iron, copper, or brass, one palm deep, but without a bottom, 

 and a rounded valve so tightly closes it that the water, which has been drawn 

 up by suction, cannot run back ; but if there are two lengths of pipe, the 

 box is enclosed in the lower pipe at the point of junction. An opening or a 

 spout in the upper pipe reaches to the drain of the tunnel. Thus the work- 

 man, eager at his labour, standing on the flooring boards, pushes the piston 

 down into the pipe and draws it out again. At the top of the piston-rod is a 

 hand-bar and the bottom is fixed in a shoe ; this is the name given to the 

 leather covering, which is almost cone-shaped, for it is so stitched that it is 

 tight at the lower end, where it is fixed to the piston-rod which it surrounds, 

 but in the upper end where it draws the water it is wide open. Or else an 

 iron disc one digit thick is used, or one of wood six digits thick, each of which 

 is far superior to the shoe. The disc is fixed by an iron key which pene- 

 trates through the bottom of the piston-rod, or it is screwed on to the 

 rod ; it is round, with its upper part protected by a cover, and has five or 

 six openings, either round or oval, which taken together present a star-like 

 appearance ; the disc has the same diameter as the inside of the pipe, 

 so that it can be just drawn up and down in it. When the workman draws 

 the piston up, the water which has passed in at the openings of the disc, 

 whose cover is then closed, is raised to the hole or little spout, through which 

 it flows away ; then the velve of the box opens, and the water which has 

 passed into the trunk is drawn up by the suction and rises into the pipe ; 

 but when the workman pushes down the piston, the valve closes and allows 

 the disc again to draw in the water. 



The piston of the second pump is more easily moved up and down. When 

 this pump is made, two beams are placed over the sump, one near the right side 

 of it, and the other near the left. To one beam a pipe is fixed with iron clamps ; 

 to the other is fixed either the forked branch of a tree or a timber cut out at 

 the top in the shape of a fork, and through the prongs of the fork a round 

 hole is bored. Through a wide round hole in the middle of a sweep passes 



