456 MEM O IR S of the 
roeltina-pot of about a gallon content, and about five pounds of 
copper'^ uppermoft j the calamine muft be mixt with as many 
caals as will fill up the pot 5 this is let down with tongs into a 
wind-furnace eight foot deep and remains eleven hours therein 5 
they call oft not above twice in 24 hours 5 one furnace holds eight 
pots- after melting it is caft into plates or lumps 5 45 pounds of 
raw 'calamine produce 50 pounds of burnt, or calcined: Brafs 
fiiruff ierves inftead of lb much copper, but a lufficient quantity 
of this cannot always be procured, being a collection of pieces 
of old brafs, which is ufually got in fmall parcels: The bell 
guns are not made of malleable metal, and cannot be made of 
pure copper or brafs 5 for it is necefTary to put coarfer metal to 
It, to make it run the ciofer and the founder^ as lead and pot- 
metal ^ bell-metal being copper and tin, and pot-metal copper 
and lead J about 20 pounds of lead are ufually put to 100 
pounds of pot -metal 3 but about 6 pounds is lufficient to put to 
100 pounds of gun-metal 5 the calamine-flones wet-e formerly 
fetched from "Poland, but fince they are fetched from thence by 
the 1)utcb. 
Seds of Oyfter-fbells found near Reading in Berkfhirej ^^y 
'Dr. James Brewer. Phil. Tranf. N" i6i. p. 484. 
THESE Ihells have the entire figure and matter of oyfter- 
fliells 5 the circumference of the ground where they are 
dug up contains, as is judged, between 5 and 6 acres; the foun- 
dation of thefe fhells is a hard rocky chalk, above which they lie 
in a bed of green fand, upon a level, as near as can be judged 5 
this Stratum ov layer of green fand and oyfter-fliells is near two 
foot deep 5 immediately above this layer of green land and fhells, 
is a bed of a bluifli fort of clay, very hard, brittle and rugged, 
which is called a pinny clay, and is of no ufe 5 the Dr. found it 
about a yard deep, and immediately above this, is a Stratum o£ 
fullerVearth, which is near two foot and a half deep, often ufed 
by the clothiers ^ and above this earth again is a layer of a fine, 
clear, white fand, without any mixture of earth, clay, pC, 
which is near feven foot deep; and immediately above this is a 
ftiflfred clay, which is the uppermoft Stratum whereof tiles are 
made; the depth of this cannot be conveniently taken, it being 
fo high a hill, on the top of which there is dug a little common 
eartK about two foot deep, and immediately under appears the red 
earth ; the Dr. dug with a mattock feveral whole oyllers with 
both their valves or fliells lying together; in the cavity of fome 
of them there is the abovemcntione^ green land; thefe fhells are 
fo 
