326 pliny's natural history. [Book XXXVI. 



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

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

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

 to and fro. 



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

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

 to send to -Ethiopia for the purpose of preparing our marble — 

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

 severity of the Roman manners thought it beneath them to 

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

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

 mation, the ^Ethiopian being of a softer nature, and better 

 adapted for 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 find it recommended*^ to rub it with Indian sand calcined. 

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

 Coptos, generally known as "Egyptian" sand. 



The above were the several varieties of sand used by the 

 ancients in dividing marble. More recently, a sand has been 

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

 certain creek of the Adriatic Sea, which is left dry at low 

 water only ; a thing that renders it not very easy to be 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, the 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. 

 For giving the last polish to marble,^" Thebaic stone °^ is con- 

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

 fine. 



*« Ajasson says that his remarks on the choice of the sand for this pur- 

 pose, are very judicious. 



*^ A recommendation worse than useless, Ajasson remarks, 



^ For this purpose, at the present day, granular corindon, or yellow 

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

 tin; the substance being repeatedly moistened when applied. 



*^ See Chapters 13 and 43 of this Book. 



