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XXIX. Dt'scrip/ion of an improved Mill for grinding 

 Fain/er/ Colours. Bi/ Air. James Rawlinson, c/" 

 Derly *. 



A HAVE herewith sent a inodcl of a machine for grindinjj 

 paint, hoping that the Society for the Encouragement of 

 Arts, Sec. n)ay not think their time entirely lost in exa- 

 mining if it has any merit; and if they should be of opi- 

 nion that it has sufiicient merit to recommend it to the^ 

 public, it cannot fail of receiving that attention, from the 

 sanction of their approbation, which mv recommendation 

 could not procure fur it. 



The hitherto very unmechanical, inconvenient, and highly 

 injurious method of grinding poisonous and noxious colours, 

 led me first to imagine a better might easily be contrived 

 for that purpose. It must be obvious to every person, that 

 the method hitherto adopted of grindmg colours on an ho- 

 rizontal marble slab, with a small pebble muller, requires 

 the body of the person who grinds to bend over that slab, 

 and consequently his head ; which causes him constantly to 

 inhale the noxious and poisonous volatile parts of the pain*, 

 which is not unfrequently ground with oil saturated with 

 litharo-e of Icv^d ; and if we may judge from the very un- 

 healtliy appearance of these men, accustomed to much co- 

 lour-grindina", it should seem the bad eflfects of this em- 

 ployment require a speedy reuiedv. 



The machine, of which I now send the society a model, 

 has not only the advantage of being an eflectual remedy of 

 this extensive and severe evil to recommend it, but it grinds 

 the colour nuich easier, nmch finer, and much quicker, 

 than any meth.od hitherto adopted. Having occasion for a 

 considerable quantity of colour-grinding in the profession 

 in which I am engaged, and that in the finest state possi- 

 ble, and having made use of this machine for several years, 

 and being more and more convinced of its utility, I thought 

 it my duty to present it to the Society of Arts, hoping that 

 it might not be altogether unworthy of their attention. The 

 roller of the machine that I use is sixteen inches and a half 

 in diameter, and four inches and a half in breadth. The 

 concave muller that it works against, covers one-third of 

 that roller : it is therefore evident, that with this machine. 



■' Frorn Tra>isnciio''^ of the Socii t\ of Arts, fee. 1S04'. — The til vof medal 

 of thf Sucitty and ten guineas wne voted tu the author fur this commu- 

 nication. 



I have 



