Mr. Mawlinson’s (Colour Mill . 
459 
H, to catch the colour on as it falls from the taker- off. 
F is a drawer, for the purpose of containing curriers 5 
shavings, which are the best things for cleaning paint- 
mills. — E is the frame. 
Previous to the colour being applied to the mill, I 
should recommend it to be finely pulverized in a mortar, 
covered in the manner of the chemists when they levi- 
gate poisonous drugs.* This process of dry-grinding is 
equally necessary for the marble slab now in use; after 
which it should be mixed with oil or water, and with a 
spatula or pallet-knife put on the roller, near to the top 
of the concave muller, and the roller turned round, which 
takes the colour under the muller without any difficulty, 
and very few turns of the roller spread it equally over its 
surface. When it is perceived sufficiently fine for the 
purpose required, it is very easily taken off by means of 
the taker-off described, which must he held against the 
roller, and the roller turned the reverse way, which 
cleans it very quick and very completely ; and the mul- 
ler will only require to be cleaned when you desist or 
change the colour. It is then turned back, being hung 
on pivots to the frame at i i , and cleaned with a 
pallet-knife or spatula very conveniently. Afterwards, 
a handful of curriers 5 shavings held on the roller, 
with two or three revolutions cleans it effectually; and 
there is less waste with this machine than with any mar- 
ble slab. 
* Or rather in an improved mill, used at Manchester by Mr. Charles Taylor, 
for grinding indigo in a dry state, of which I have annexed a drawing, and re* 
ference, to render the whole business of colour-grinding complete . — Note of the 
Author. 
This is the same apparatus as was used under the name of a philosophical mill , 
in the laboratory at Gottorp, about the beginning of the last century. See the 
memoir of Dr. Joel Langelot, with an engraving, in Lowthorp’s Abridg- 
ment of the Philosophical Transactions, vol« 3, p , 3 18.— N icholson. 
