O F C O R N W A L L . gq
building, is t t e in ^or^ing, yet hard enough for every kind of ftone
work m water as well as out, and much foperiour to Portland '.for
jtejps and water-works: it is alfo fent rough-hewn to Briftol in large
dabs, which arc there forther policed for calling thin broad platS
? 9f , Cf pP f ‘ 1 Thcpyramid m Arwinekgrove at Falmouth, isfolid,
and bmk pf tfo^fto^. It was eroded by. the late Martin KilligreW
S b years Ilf and m m at the expenX of
+55 W d s , fourteen feet wide at the bottom, and forty feet high
each. fide, correfpondent.fo number and fize of ftones to the W
%re r t b ^ H a t e X X iy . Fig^v2., the middle Iayed with roughly-
fijuared ftone^nd their interfaces filled with liquid cement: fo that
a more.durable work can fcarcely be imagined; and great pity-it is
Z that- it rife uqt-gfeced as confpicuou* as: its Mdity defer*«. Gentlemen,
face tfie fronts of their houfes with this ftone to good eSe&
as may befeen at Garclew,the feat of William L embn,E% Plate X t
j p a g f 9P, and other places. O f two fpecimens weighed ip the hy-
balance, one weighed to water as 2 to i , the other
^ ^ h ^ y as 2^ - . r t ° J \ .There » a very gc^d granite of the
fame. kind in Karn-mel-bal in St. Juft. ;
In ^ - Parifll of' Modern there is awery pretty mooxftone, but
rare ; the ground milk-white, gloflyquartz or, coarfe cryftal, the
cbcirge- confiftingof large, black fpots o f cockle. Rocbrock, in the
j j p f f e o f Roch, differs only, from this, that the charge is finall black
ipecks* from the tenth of an inch and under, vefy numerous, thickly
^ e q p a l iy difperfed, fo as to be o f a mottled colour : this ftone k
m largemiaffes. The tendereft and fieeft kind o f this -ftone, and
npateft for foldings, is that of Tregpnin, in theParifh of Br£ag, of
Which is buik the portico of Godolphin houfe, the feat of the Right
Honourable the Earl of Godolphin, Plate XII. and the New C h S
at Helfton,. the donation of the fame munificent Lord. The ground
is of a white, opake grit, tender almoft as clay, in t e r r e d with
granules of quartz, cinereous,- tranfparent, laminated, final! from
the eighth of an inch and under. The ftone is foft, and eafy for
working, efpecially when frrftraifed, but afterwards hard arid Lifting;-
extreamly white when newly wrought, but apt to coneraft a mofly
green hue in time. It weighs to water as 2 - - **, to 1. O f all the
granite kind in Cornwall, this, i f I have been rightly informed by a
gentleman ° who has tried many experiments this way, is moft proper
for making porcelain.
In the parifh of Ludgvanp there is a fingular kind o f granite; Dovecolour
. " By which, as well as many other experiments,
jt appears, that in parts of the very fame concrete
one the ground and cbaigejri mixed in different
P,r?Port[oils> an“ ^la.t th’erq is no determining pre-
cilely,. but onlylriigetieratsUid/at* medium, the
weight of any fort of ftone by experiments made
upon any Specimen.
; g| i Mr. Cbokworthy of Plymouth
p Rectius Ludvon.
the