512 THE CENTURY, 



83. 



A Rafping-mill for Harts-horn, 

 whereby a child may do the work 

 of half a dozen men, commonly 

 taken up with that work. 



[A Rasping-mill.~\ This description of mill is largely 

 in use for rasping dye-woods, and has undergone a 

 great variety of modifications. 



8 4 . 



An Inftrument whereby perfons 2 

 ignorant in Arithmetick may per 

 fectly obferve Numerations and 

 Substra6lions 3 of all Summes and 

 Fractions. 



a a person. 3 numeration and substraction. MS. 



[An arithmetical Instrument^ There is in the British 

 Museum a manuscript description, with a large engrav 

 ing, of the serpentine scale invented by Thomas 

 Browne, of Fenchurch Street, London, in 1631, by 

 means of which &quot; instrument all kinde of questions in 

 Arithmetike, Geometry, &c. are speedily resolved/ 

 Brit. Mus. Birch MS. No. 4407. 



Sir Samuel Morland, in 1672-3, published a small 

 treatise, being &quot; The description and use of two 

 arithmetick Instruments ;&quot; a second title mentions, 

 &quot; A new and most useful Instrument for Addition and 

 Substraction of pounds, shillings, pence, and farthings,&quot; 

 which he . &quot; invented and presented to his most 

 excellent Majesty, Charles II. 1666.&quot; 



