.TJ6 PLINY'S NATURAL HI STOUT. 



division, though apparently effected by the aid of iron, is in 

 ivality effected by sand ; the saw acting only by pressing upon 

 the sand within a very fine cleft in the stone, as it is moved 

 U> and fro. 



The 4 " sand of ^Ethiopia is the most highly esteemed for this 

 purpose; for, to add to tho trouble that is entailed, we have 

 to send to ./Ethiopia for the purpose of preparing our marble 

 aye, and ns far as India even ; whereas in former times, the 

 severity of tho Roman manners thought it beneath them to 

 repair thither in search of such costly things even as pearls ! 

 This Indian sand H held in the next highest degree of esti- 

 mation, the ./Ethiopian being of a softer nature, and better 

 adapted lor dividing the stone without leaving any roughness 

 on the surface; whereas the sand from India does not leave so 

 smooth a face upon it. Still, however, for polishing marble, 

 we tind it recommended 49 to rub it with Indian sand calcined. 

 The sand of Naxos has the same defect ; as also that from 

 Cuptos, generally known as " Egyptian'* sand. 



The above v/ere the several varieties of sand used by tho 

 ancients in dividing marble. More recently, a sand ha> been 

 discovered that is equally approved of for this purpose; in a 

 eertain creek of the Adriatic Sea, which is left dry at lo\v 

 water only ; a thing that renders it not very easy to he found. 

 At the present day, however, the fraudulent tendencies of our 

 workers in marble have emboldened them to use any kind of 

 river-sand for the purpose ; a mischief which very few em- 

 ployers rightly appreciate. For, tho coarser the sand, the, 

 wider is the division made in the stone, the greater the quan- 

 tity of material consumed, and the more extensive the labour 

 required for polishing the rough surface that is left ; a result 

 of which is that the slabs lose so much more in thickness. 

 Fur giving the last polish to marble/ Thebaic stone 61 is. con- 

 sidered well adapted, as also porous stone, or pumice, powdered 

 tine. 



4 " Ajasson says that his remarks on the choice of the sand for this pur- 

 pose, are very judicious. 



A recommendation \vorse than useless, Ajasson remarks. 



w For this purpose, at the present day. granular corimlnn, or yrllow 

 emery, is used, as also a mixture composed of the oxides of lead and of 

 tin ; the substance btin? repeat* dly moUtened when applied. 



Si See Chapters 13 and -io of this 15ouk. 



