Rich tin-
mines.
fped&enii* .that it .is fixed on a bafe of .a ß a? B
wS^compofitionfs micaceous, fealy, and foft, like'burnt tm ; it
x<m * aqua fir tk i and as it has tlie exterior of native tin, might
ooffibly beimiftakentfor fuch, though meer talc., I I -Fie xxi. A pentahedral pyramid of,cryftalhpe tin, the ridges and
fides concave,- With a flender rhomboidal, well-finifhed plane ort.the
apex; itthasmany fhining yeUow.j/ta»«/« in it, and not lmprobaS
i? n °A quadrilateral pyramid, o f tin, with a fiender rhomboidai
plane on one o£. the angles, with feme fparks of yellow as betöre ;
but ftiore refinous. a ' H H I - f l f i
xxiii. A tin-grain extended like a book unfolding. Thefe four
laft curious fpecimens came from. Huel-fortune in iBreag. .
xxjv. On a rhomboidal bafe two quatrilateral pyramids applied
bafc to bafe. 9 §g 1 ^ u ; 'Tr~ :o - . , .
xxv. ! Two pentahedral pyramids joined bafe to: bafe, each having
a pentagonal cellule in the center of its^apex. Both frpm St.,Mewan
Glebe. ‘ ^ f ? . ' j
xxvi. The fide-view of: two. hexagonal pytamiQ&Ptntan joinep
bafe to bafe. . . H a " - s i - J .. . g
xxvn. One of the pyramids with the apex in,ffpnt. >
r xxvin. Sedion a t -the fmdture of a pieeepf.tin in -undjdated M-
grailed fheaths, nearly of an equal thicknefi throughopt, p lo fin g
one another; ' the cmtral npcl^isis bafe cryfiaf. , HR M § | M |
xxix. A white pyramidal grain o f tin with tranfyene ;• beltslpr
tty; A red, tetrahedral pyramid of tin .found in a^eamrwork
in St. Aufld, 1757.; modi I c " nr
Let it be obferved, in the laft place, that, whoever ^the.figufe of
thefe cryftals is, this is the pureft ftate of tin-pre., thatjorg jgodp|p
ing möft metal which has moil of thefe grains, and läjg£li,.<u^r
any equal fiirface; and black-tin : is ,no more than.thefe cryftals
cleared of their impurities. -..--nilocj ■: -i
The’ richeft tin-mine I have ever . heard pf*: äs to the- quality of
the ore,äs one in the parifh of St. Agnes, near the_ heacon, ‘eailled Bol-
berou. Several parallel and .contiguous veins, mpftly ofdarger-grain
cryftals, make the treafiire of tin in filch quantity, that, in the
year 1750, they could not get horfes enough in the neighbourhood
to carry the tin from the mine to the melting-houfe, but carried it
in ploughs, a very unufual fight (though doubtlefs a more effectual
and eafy draught where the ways will admit of wheels.) Great
part of the ore was fo rich and pure that it needed not to be
ftamped, and the lode is fo large that it affords vaft rocks of tin :
one rock, in March 1750, was, brought to Killinick melting-houfe
near
near Truro, which, as a clergyman prefent at the weighing informed
ifi#weighed fi-^hfindred and fixtyftbur. pounds* and. .it, brought
dpfen and half ^n'itWerfty, in, the > ftone without Ramping fand
Aejling, I hay^paQ©'been iq^tjmed,'tbaftone ftone, brouglififjtq
^ mglrihg-houf^fifom the famoWsOrk, weighed i 2q^. pou a ^O I tis
judged., that th^ latf- Mri Donithgafifi \Vho>1iad the whole adventure^
^bdy.worsked it^a#|hi^rfe>le expery|@, -in a fewlyeUrs, laftfpaft'jgpt ah
fpp^ifpJy thoufand pounds, clippby this,;ipine, andn.much more
tin, b e n ig h t hay^*«Caifed |earlyri|;l^,pleafed. ItMiaimihessat prefent
deep and wroiight atfU grqafe S p e n c e by a *<wat©i-wheely bobs,
and, whims; -brftkthe ^lode is wijie,&pehquality^»-,and turns out
gpeat profit,:
6: ;Tbe i mine • which ’ has turned hoti%,(tbfir ifeofi ga)n| »and )the
gpeateft quantity of- tin as .yet known,. is ^ ^ IM g b q ^ in the parifh
®fSt.;Mewan, where it appjarsjby the old.bpqks,, tha,^.J^ p adventurers
hhv^got1 twenty thoufand pounds,annually fpr a Meat num-l,
her' oftyears? following
flow far the Bhenicians and Grecians interefted themfelves in sect?, xxr.
the „management of our mines,„ and whether, >gst is .more probable^™ m% °C
they werq any other than the merchants to purchafe and export ?du^nd prefent
tin whedi raffed; cannot- Bs '.decided; but as it. appears? a^pijlcntfe1^“1' ^
from tfip teftirfioriy-of Polybius-,-} Stfilbo^ Diod.| Sicfiluis,^and Plinyfcnaries- *
and jo thers,; that Romans-; traded, hither for, tin.,, and improved
the fiahabitnntfein mining-; £o by fheir coins, ifepillchres, and.fagri-,
fical fiiffiuments found in and neai^the' aucierijt .firiT.woiks, , (whither,
nothing pefeeivable’ could'tempt ? them, . : but the riches, of thofe
mkteB&fit isfUis apg^eiit tfie Romans worked'thofe mmes,;Qr,at .
leaffi/sWth ^thefi ilydierss ffipefintended the workmen. « At this time,
jtbfe. no property ; they were the -working
miners under their conquerors, but what regulations they were fufi-
Tedt to is, uncertaims .4:
. Tlfei Saxons are laid to hayesnegledled the Cornifh tin-mine^;
but indeed they had no’ authority in Cornwall till it-was entirely
conquered by Athelftanjtl^er: which .they ,had no;>feifure, thdr.
attention was wholly taken' Up by the Danifh wars; -thefe wars
laft prevailed, and . the Danes, foon after gave way to the Normans,
and thqfe laft promoted the Working of our mines to - their,great
emolument. However, in the time of King John, I fiqd^the- pro-
dudf of tin in this county very inconfiderable, the righfiof working:
for tin being as yet wholly in the King, (King John -being at this
time alfo Earl of Cornwall) the pfoperty of the tinners precarious and
• x Letter from Mr. W. Rofwariijof Trufo, Ffife. mm 1756.
C c c
’ See Antiq. of Cornwall, pagey^q-
unfcttled,