BOOK VIII. 



285 



way ; the lower part of the head is three palms long and the upper part the 

 same length. The lower part is a palm square in the middle for two palms, 

 then below this, for a length of two digits it gradually spreads until it 

 becomes five digits square ; above the middle part, for a length of two 

 digits, it again gradually swells out until it becomes a palm and a half square. 

 Higher up, where the head of the shoe is enclosed in the stem, it is bored 

 through and similarly the stem itself is pierced, and through the opening of 

 each, there passes a broad iron wedge, which prevents the head falling off the 

 stem. To prevent the stamp head from becoming broken by the constant 

 striking of fragments of ore or rocks, there is placed around it a quadrangular 

 iron band a digit thick, seven digits wide, and six digits deep. Those who 

 use three stamps, as is common, make them much larger, and they are 

 made square and three palms broad each way ; then the iron shoe 

 of each has a total length of two feet and a palm ; at the lower end, it is 

 hexagonal, and at that point it is seven digits wide and thick. The lower 

 part of it which projects beyond the stem is one foot and two palms long ; 

 the upper part, which is enclosed in the stem, is three palms long ; the 



A— Stamp. B— Stem cut out in lower part. C— Shoe, D— The other shoe, 



BARBED AND GROOVED. E — QUADRANGULAR IRON BAND. F — WEDGE. G — TAPPET. 



H— Angular cam-shaft. I— Cams. K— Pair of compasses. 



