Principles of Geology

Ninth Tenth Edition. Edition.

Page Page

291

306

Additions and Corrections.

origin of the swatch' and the mode of formation of the elevated banks of rivers.

495 Various causes of currents treated of more fully than in the former edition.

514

323

539

334

340

Waste of the coast of Norfolk illustrated by the ruins of
Eccles Church as they appeared in 1839 and in 1862. A
drawing by the Rev. S. W. King of the church in 1862.
St. Michael's Mount, Cornwall-Three views of the Mount
showing its identity with the Ictis of Diodorus-Drawing
of a block of tin dredged up in Falmouth Harbour.
563 Temperature of different divisions or basins of the Mediter-
ranean compared to that of the Atlantic-Saltness of the
Mediterranean, and a diagram illustrating the result of
Captain Spratt's survey.

568 Shoals and valleys in the German Ocean-The Silver Pits
and Dogger Bank-Comparison of the recent deposits of
these shoals and the crag of Norfolk and Suffolk.
616 Internal talus of Monte Nuovo, containing fragments of
marine shells and pottery, with a section of the mountain.
Ropy lava and origin of this structure.

625 633

Hypothesis of elevation craters not applicable to Somma or Vesuvius-Ravines on the north side of Somma, and the light which they throw on its structure, from observations made by the author in 1857 and 1858-Presence of land-plants and absence of contemporaneous marine shells in the ancient tuffs of Monte Somma.

The reader may also be interested in knowing the dates of the successive editions of this treatise, as well as of two other of my geological works, which are intimately connected with it.

List of the dates of publication of successive Editions of the Principles,' the Elements,' and the Antiquity of Man.'

Principles, vol. i. in 8vo., published in

Jan. 1830.

New edition (called the 3d) of the whole work in

4th edition, 4 vols. 12mo.

Elements, 1st edition in 1 vol.
Principles, 6th

Elements, 2d edition in 2 vols. 12mo.

Principles, 7th edition, in 1 vol. 8vo. published in

Elements, 3d edition (or Manual of Elementary Geology), in

Jan. 1852.

June 1853.

Feb.-Nov. 1863.

Jan. 1865.

Elements, 4th edition (or Manual) in 1 vol. 8vo.
Principles, 9th edition, published in 1 vol. 8vo.
Antiquity of Man, 1st, 2nd, and 3rd editions
Elements, 6th edition, in 1 vol. 8vo.

Principles, 10th edition, in 2 vols. 8vo., the first now published. Nov. 1866.

The Principles of Geology,' in the first five editions, embraced not only a view of the modern changes of the earth and its inhabitants, but also some account of those monuments of analogous changes of ancient date, both in the organic and inorganic world, which the geologist is called upon to interpret. The subject last mentioned, or geology proper,' constituted originally a fourth book, now omitted, the same having been enlarged into a separate treatise, first published in 1838, in one volume 12mo., and called 'The Elements of Geology,' afterwards recast in two volumes 12mo. in 1842, again re-edited under the title of 'Manual of Elementary Geology,' in one volume 8vo. in 1851, and lastly under the title of Elements of Geology,' in one volume 8vo. in 1865. The Principles' and 'Elements,' thus divided, occupy, with one exception, to which I shall presently allude, very different ground. The Principles' treat of such portions of the economy of existing nature, animate and inanimate, as are illustrative of Geology, so as to comprise an investigation of the permanent effects of causes now in action, which may serve as records to after ages of the present condition of the globe and its inhabitants. Such effects are the enduring monuments of the ever-varying state of the physical geography of the globe, the lasting signs of its destruction and renovation, and the memorials of the equally fluctuating condition of the organic world. They may be regarded, in short, as a symbolical language, in which the earth's autobiography is written.

In the Elements of Geology,' on the other hand, I have

treated briefly of the component materials of the earth's crust, their arrangement and relative position, and their organic contents, which, when deciphered by aid of the key supplied by the study of the modern changes above alluded to, reveal to us the annals of a grand succession of past events—a series of revolutions which the solid exterior of the globe, and its living inhabitants, have experienced in times almost entirely antecedent to the creation of man.

In thus separating the two works, however, I have retained in the Principles' (Book I.) the discussion of some matters which might fairly be regarded as common to both treatises; as for example, an historical sketch of the early progress of geology, followed by a series of preliminary essays to explain the facts and arguments which lead me to believe that the forces now operating upon and beneath the earth's surface may be the same, both in kind and degree, as those which at remote epochs have worked out geological changes.

If I am asked whether the Principles' or the 'Elements' should be studied first, I feel much the same difficulty in answering the question as if a student should enquire whether he ought to take up first a treatise on Chemistry, or one on Natural Philosophy, subjects sufficiently distinct, yet inseparably connected. On the whole, while I have endeavoured to make each of the two treatises, in their present form, quite independent of the other, I would recommend the reader to study first the modern changes of the earth and its inhabitants as they are discussed in the present volume, proceeding afterwards to the classification and interpretation of the monuments of more remote ages.

It will be seen in the foregoing list of the dates of publication, that in 1863 I brought out a volume on the Antiquity of Man,' or to state the title more fully, On the Geological Evidences of the Antiquity of Man, with Remarks on Theories of the Origin of Species by Variation.'

The subject-matter of this work coincided in part with

that treated of in the Principles' and Elements,' namely, the fossil remains of Man and his works; but whereas these topics occupy a few pages only in the Elements' and 'Principles,' half a volume is devoted to them in the 'Antiquity of Man.' In the latter treatise also, the account given of the Glacial Period, and its relation to the earliest signs of Man's appearance in Europe and North America, is much more expanded than in the Elements' and 'Principles,' and regarded from a different point of view. The manner also in which the origin of species is handled in the Antiquity of Man' will be found to be different in many respects from that in which I shall view the same subject in the concluding volume of this work.

CHARLES LYELL.

73 HARLEY STREET:
November 6, 1866.

CONTENTS

Geology defined-compared to History-its relation to other Physical Science-

not to be confounded with Cosmogony