Mr Robertson on the Mechanical Arts of Persia, 299 



standing its quick motion : it is worked by depressing the 

 small bar, which reascends at every stroke. A similar instru- 

 ment of smaller size is used in this country in die-sinking. 



Horse shoes are made thin and light, with a sharp project- 

 ing edge on the outside of the lower rim ; this projection, and 

 the large heads of the shoe-nails, enable the horses and mules 

 to keep their feet on smooth rocks or ice. As the greater 

 part of the hoof is protected by the shoe, the foot is not easily 

 injured by sharp rocks ; and the small hole in the centre of 

 the shoe enables the animal to lay hold of the sharp projec- 

 tions met with in steep and otherwise impassable tracks, so 

 that the horses shod in this way can climb and descend steep 

 rocky paths with the greatest safety and speed. Sometimes 

 a piece of felt is placed between the shoe and the hoof. 



Turning in wood. — This operation is performed by a car- 

 penter while sitting on the ground. Two stakes are driven 

 down before him, a short distance apart, and an iron spindle, 

 with a small drum attached, revolves between them. The 

 spindle is passed through the wood which is to be turned, and 

 with the assistance of a bow and string passed round the drum, 

 the spindle is made to revolve rapidly. The bow is worked 

 backwards and forwards by *he left hand, while the right holds 

 the cutting-tool supported on a block of wood. 



Turning in metal is almost unknown. 



Stone-cutting, — As the buildings are generally made of clay 

 or brick, stone-cutting is little practised in Persia. Grave- 

 stones, millstones, and a few other articles, therefore, embrace 

 the whole of the works of this description. When the work 

 admits of it, the stone-cutters sit upon the ground. The prin- 

 cipal tools are, small double-pointed picks, and mason irons 

 resembling large nails, some pointed, and some chisel-shaped. 

 With these tools the stone-cutters work very slowly, and it is 

 only after immense labour that they succeed in bringing a hard 

 stone to the required form. 



For boring in stone, the instrument is an iron rod steeled 

 at the end, but instead of a chisel point the end is cut flat off. 

 Two parallel regular grooves are cut deep across this face, 

 and these are intersected by three others at right angles, thus 

 diving the end of the rod into twelve compartments. While 



