I have to acknowledge my obligations to various gentlemen for
assistance in the progress of this work, but especially to the
following:
To RICHARD TAUNTON, Esq. M.D. for his loan of Mr Hals’s Manuscript.
To the late Right Honorable FRANCIS BASSET, BARON DE DUNSTANVILLE,
for his supplying me with Mr. Tonkin’s Manuscript.
To HENRY S. BOASE, Esq. M.D. for his most liberal communication of
an abstract for each Parish, taken from an accurate and minute
Geological Survey of the whole County, made by himself.
To the Right Honorable HENEAGE FINCH, EARL OF AYLESFORD, for his
allowing me the use of a Transcript of Mr. Hals’ Parochial History
as it now exists, formerly belonging to the late Mr. Lysons.
To GORDON WILLIAM FRANCIS GREGOR, Esq. for his supplying me with an
emblazoned copy of the last Visitation of Cornwall by the Heralds
in 1620.
To Sir HENRY ELLIS, K.H. F.R.S. Sec. S.A. for the communication of
his MS. additions to Tanner’s Notitia Monastica for Cornwall.
To the Rev. JOSIAH FORSHALL, M.A. F.R.S. late Fellow of Exeter
College, Oxford, and now Keeper of the Manuscripts in the British
Museum, for his extracts from a very ancient Manuscript relative to
the See of Bodmin.
I have to acknowledge, with my best thanks, the assistance of THOMAS
HINGSTON, Esq. M.D. afforded by his arrangement of Extracts
relating to Cornwall, from the Itinerary of William of Worcester;
and by an original communication on the Etymology of Names of
Places within the county.[1]
The only existing Manuscript of Mr. Tonkin’s Work having remained for
some years in the possession of Mr. Whitaker, he added to it various
notes and ilustrations, frequently interlined, or blended with the
original writing, so as to render the task difficult, in many cases,
to distinguish the one from the other. In almost every passage of any
length, Mr. Whitaker’s additions are marked with a [W.]
Geology having pressed forward during the present century, at a pace
unexampled in other sciences, may reasonably be expected to reach new
discoveries in comparatively short intervals of time; these have been
reduced, however, almost to instants in respect to Cornwall. After the
very able, minute, and laborious investigation made by Doctor Boase,
of every district, of every parish in the whole county, the work of
discovery would seem to have been completed, at the least for several
years; but Mr. de la Beche came soon afterwards into Cornwall, under
the sanction of Government, assisted by officers of the Engineers
employed on the great Trigonometrical Survey; and this eminent
Geologist has, in consequence, been enabled to lay down the various
main lodes, the cross courses, the elvans, &c. together with the
junctions of granite, greenstone, and killas, with an accuracy and
discrimination never before attained, nor ever approximated to, except
by Mr. Richard Thomas, in his survey of the mining district, made
about twenty years ago.
Mr. De la Beche has also been enabled to deduce several general laws
observed in the direction of cleavages, in the dip of strata, in the
heaves and slides of lodes, all of which will be detailed in an
eagerly expected volume, together with a discovery most unexpected.
The saxa metallifera of Cornwall had always been supposed referable to
a very remote period of geological epochs, far anterior to the age of
organic remains; till this opinion became shaken by the discovery of
shells, or of their impressions, in the hard schist rocks near
Tintagell: others were subsequently found more to the south and west;
till at last Mr. De la Beche has detected the remains of organized
life adjacent to a productive Copper Lode.
Two other eminent geologists, whom it would be equally idle and
presumptuous for me to praise, have established the fact of a
formation in the northern parts of Cornwall and Devon, not less
unexpected than the discovery just noticed.
Professor Sedgwick and Mr. Murchison having investigated the
deep-seated rocks in Wales, and in the adjacent districts, have
finally traced the carboniferous series under the Severn, and so far
west as the level ridge of land, extending from near Launceston to the
sea coast between St. Gennys and Botreaux Castle, along which plane
the escarpment manifests itself in a very conspicuous manner.
While these discoveries may be considered as in progress, a Cornish
gentleman, but one whose genius does honour to the nation, Mr. Robert
Weare Fox, has deduced from galvanic action on metals, on their
oxides, on their sulphurets, and on their saline solutions in water,
the only theory that has yet accounted for the various phenomena
observed in metallic lodes; and extending still further his
investigations to the recently discovered connection between electric
energies and terrestrial magnetism, Mr. Fox has been enabled to give
more than probable reasons for the extraordinary fact of some metals
usually selecting, in all parts of the world, lodes or fissures
running nearly east and west, and why other metals prefer rents at
right angles to the former; and in respect to the fissures themselves,
Mr. Fox has remarked appearances inducing him to believe that lodes of
considerable breadth have not been formed by any one great and sudden
rending of the earth; but that, in a manner similar to the rising or
to the sinking of land, by the gradual action of causes now well known
to exist, those clefts have been enlarged from time to time, and have
as frequently received additional deposits, easily discriminated from
each other.
Mr. Fox appears also to have settled beyond the possibility of doubt,
the long-agitated question respecting the temperature of mines, by
establishing a general relation between increases of heat and depth;
although the ratio cannot be reduced to any definite formula, being
liable to vary with the presence of more or less water, and with the
different conducting power of rocks, since mines in granite and in
killas differ by several degrees of heat at the same level: yet the
increase corresponds so generally with greater descents into the
earth, that elevation of temperature, and not the expense, nor the
difficulty of exhausting water, appears likely to oppose the final
limit to the progress of mines in depth.
In continuation of the same trains of reasoning and of thought, Mr.
Fox has been led to investigate the important elements of variation
and dip of the magnetic needle; and in pursuing these inquiries, he
has invented an instrument possessed of far greater accuracy than any
one previously employed, and which at this moment is in actual use,
through the enlightened liberality of our own and other governments,
in various and distant portions of the globe.
Mr. Henwood is about to lay before the Public a Work containing the
results of more extensive and scientific researches into the nature of
Lodes and Fissures, than have perhaps been ever executed by any
individual. Mr. Henwood is well known to geologists: I shall therefore
only add what I think myself bound in duty to notice, that an original
appointment in the Stanneries, and a subsequent promotion, have been
bestowed on Mr. Henwood, through the medium of Her Majesty’s Duchy
Officers, and principally of Sir George Harrison, in consideration of
his scientific attainments, and of his desire to render these
attainments available to the development of further inductions.
* * * * *
I have endeavoured to render the work cheap by adopting the octavo
form, and by abstaining from all decoration, except a slight sketch of
the Pitt Diamond, which by raising that family into an influential
situation, has modified the fate of Europe in a degree impossible to
have been contemplated by the Regent Duke of Orleans, when he
purchased that bauble at the expense of an hundred and thirty-five
thousand pounds; and excepting also the Tomb of Archbishop Tregury, a
view of Cotehele house, and the Seal of a Corporation, all of which
had been previously cut on wood. I have abstained from further expense
with the view of placing my work in the hands of as many persons in
Cornwall as I possibly could, thereby diffusing the entertainment
likely to arise from Local Anecdotes, from Provincial Occurrences, and
from Historical Events, not of sufficient general importance for
securing to themselves a place in national records. I have caused an
ample Index to be prepared for the whole work; and among the
Appendixes will be found an Index to the Survey of our most respected
historian Mr. Carew; and I will add as a proof of my own
disinterestedness, that I have engaged to leave with the Publishers
all the profits, if any should arise, reserving to myself the much
more probable alternative of sustaining the loss.
The concluding paragraph proves the least agreeable of my work. I am
sorry to say, that the Typographical errors far exceed my expectation.
I must entreat of all my readers to excuse them, and to correct the
Text from the too extensive Tables of Errata. The want of early habit,
dimness of sight, and absence from the Press, must be alleged on my
behalf; perhaps the compositor may plead unusual names or terms, and
subjects not rendered familiar by his ordinary practice.