Page:The parochial history of Cornwall.djvu/27

Rh 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, etc. 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