OF CORNWALL. 157 
diftance find a part of the fame natured tin-lode as they worked 
before, and in the fame direction. When the parts of the fame lode 
are found thus feparated from each other, the tinner’s exprefiion is, 
that the lode is heaved or ftarted ; and, as much may depend on the 
reader’s clearly apprehending what is here meant, let us recur to the 
explanation of figures. Let AB (Fig. v. Plate xvn.) be the lode 
firft wrought ; the miners finking till they come to B, there find 
no more lode ; they fink a little farther in the dire&ion A B, but 
to no purpofe ; guefiing then from their experience in like cafes 
that the lode is heaved, or, more properly fpeaking, ftarted, they 
let alone the bottom B, and drive a level paflage or drift to C ; 
there, to their comfort, they find a part of the former lode C D ; 
and having worked it down to D, where it difappears, they drive 
again acrofs to E, and fo work it down to F, or as far as it goes ; 
and when they find it no more in that direction, repeat the fame 
fearch to as good purpofe as before, fo that experienced workmen 
can tell nearly at what diftance, and in what place, the ftarted lode 
is furely to be found. . . 
In the lands of Kelluz, in St. Erth, the lode is ftarted to the 
north twenty-five fathoms ; but this is looked upon as very extra- 
ordinary : the fame fractures are obferved in the coal-mines, where 
there are fometimes, though rarely, three dippings, (as Dr. Plot, Staf- 
fordfhire, page 130, fays) and the coal is faid to leap: the colliers 
alfo from experience know where to find it again. 
Now in this remarkable phenomenon, it firft appears, that A B, 
CD, E F, are lb many feparate portions of the fame lode ; for 
they confift of the fame pabula> the lame metal, and make nearly the 
fame angle with the horizon, and abruptly and equally vanifh ; being 
broken off at B D F, at one and the fame diftance nearly they ap- 
pear again ; all irrefragable evidences that they are not different lodes, 
but each a diftindt frujlum of the fame lode. 
Secondly, That this lode was formed before the fiffure which 
contains it became inclined and fractured in this manner ; for B 
was joined to C, and D to E, whereas now they are at a diftance. 
Thirdly, That there muft have been three fucceftive different 
fhocks which could create three fuch fractures. 
Let us fee therefore whether the fubfidence of the Jlrata , the 
caufe before afiigned for the dippings of the lodes, will naturally 
account alfo for this their very lingular disjointed ftate. 
Firft then, from thefe and feveral other apparent alterations in the sect.x. 
bowels of the earth, it is highly probable, that the Jlrata were not Caufe of frac- 
, r , - ’ 1 i r 1 r 11 1 • tured lodes. 
only unrooted, fhaken, and brought to rail, once only, or twice, 
but feveral times. Suppofing then the lode N F (Plate XVII. Fig. v.) 
S f in 
