m 
Srwk-MaJcing. 
This IS the mode of manufacturing the common grey 
Stocks for walls and common buildings ; but some brick* 
makers, in order to mix the soil and ashes more regularly, 
perform it with a machine, called a clay-mill, which a 
horse turns round. This machine consists of a tubor^ 
tun fixed to the ground, in which is placed perpendicu- 
larly an instrument resembling a worm or screw ; the soil 
being put in at top is worked down by the rotary motion 
of the worm, and is forced out at a hole made on the side 
near the bottom of the tub, A man supplies the tub 
with fresh soil, properly moistened, while the person who 
supplies the moulder keeps removing that which is thus 
prepared, or pressed out. 
Washed malms, or more properly marls, are made 
with still greater attention : a circular walled recess is 
built about four feet deep and from three to four feet wide^ 
paved at bottom, and from ten to twelve feet diameter, 
having a horse-wheel placed in the centre ; the ground is 
raised all round it, and a platform made upon a level 
with the top of the recess. On this platform the horse 
walks, a pump is fixed into a well, as near to the platform 
as may be, to supply the recess with water as often as 
occasion may require. A harrow made to fit the recess, 
and thick set with long iron teeth, well loaded, is chained 
to the traces of the horse, who drags this after him ; a 
man wheels a barrow full of soil previously prepared in a 
heap the same as for the common stocks, and shoots it 
regularly round the recess, he then pumps a certain quan- 
tity of w^ater, which, by means of troughs or shoots, runs 
on it, and sets the horse in motion. The harrow being 
loaded accordingly, forces its way into the soil, admits 
the water into it, and by thus tearing and separating it, 
mixes the ingredients at the same time that it gives an 
opportunity for stones and other ponderous substances to 
subside to the bottom. The man keeps supplying it 
Vol. II. 3 E 
