It is not a little curious that twice in five years the British Islands have been visited with meteoric falls; in each case a single specimen has been found and, the one a small block of iron, the other a small block of rock, they constitute the prettiest little cabinet specimens of the two chief typical classes of meteorites. The former fell at Rowton, in April, 1876; the other near Middlesborough, in Yorkshire, on March 14th, 1881, and will be described later on.

In England the ice seems to have been heaviest in Wales and the N.W., and lightest on the East and S.E., where it appears to have thinned off altogether, and the evidence of depression corresponds with this. If we draw a line from Dover to Anglesea, we find proof of great submergence in Wales, decreasing to zero as we approach the English Channel. and Prof. Hughes of Cambridge, in a recent paper “On the Evidence of the Later Movements of Elevation and Depression in the British Isles,” read before the Victoria Institute, says: “As we trace these movements north to the borders of the mountains, we find evidence of greater sinking and greater elevation.”

There is an unfortunate Nemesis attaching to great discoveries and generalizations, which has not been sufficiently noticed. When men have been floundering about for years in a quagmire of confusion and difficulty, and some brilliant pen points out a clear waj' by which the tangle may be threaded,—a way which is so ingenious and simple that it at once seizes upon the current scientific thought, and compels the adhesion of everybody,—it inevitably produces a period of stagnation and for a while dwarfs inquiry. What is so palpably true and simple as the explanation of a very perplexing difficulty is taken to explain all the difficulty, and, for a while at all events, men's energies are devoted to bringing every apparently aberrant and stubborn fact within the new law or the new process; and every effect, however remote, is traced by a direct way or by a zigzag to the prime cause which has proved so fruitful. It is only after an interval, when men have digested and incorporated the new theory into their daily creed, and it no longer overawes them by its freshness, that they are in a mood to ask soberly whether, after all, too much has not been demanded from one cause,—whether, after all, the intricate and far-fetched explanations, which are necessary to connect that cause with effects with which we are familiar, is not illegitimate,—and whether we must not supplement it by some other cause, which has modified and altered its work, if we are to solve the whole riddle.

During the year 1871, in connexion with his duties upon the Geological Survey of Sweden, Linnarsson made a careful study of the Lower Palaeozoic strata of Dalarne and Jemtland, publishing the fruits of his observations in the following year. Dalarne had been already most successfully investigated by Dr. Sven. Törnquist; but Linnarsson, familiar with details of the better known succession in Westrogothia, was enabled to throw much new light upon the crumpled and shattered strata of this region.

We must now turn to the theories which make these terraces to be deposited by the rivers when so charged with water that the whole valleys, from their solid foundations up to a height of at least 80 feet, were filled with water. These theories postulate no gigantic denudations extending over limitless ages, but accept the valley terraces as fluviatile deposits left along their own banks by the rivers when, by means of exceptional causes, they were, at one time, so flooded, that they actually reached the upper level terraces which in fact represent their old banks when so flooded. Two causes for such abnormal floods have been assigned. Mr. Tylor postulates a Pluvial period, characterized by most exceptional rainfall; while Mr. Belt urges that these floods were caused by the pounding back of the European rivers, and the consequent formation of a European lake by a great Atlantic glacier.

Any geologist who has spent a short time at Eisenach, and has examined any of the numerous road- and hill-side sections in the district about the celebrated Wartburg, must have been struck, as I was myself several years ago, with the enormous development of the breccias and conglomerates interbedded with well-stratified sandstones and marls; and this district is fairly typical of the Thüringerwald. For an account of these the reader must be referred to Siluria, to the paper by Murchison and Morris before mentioned, and to Credner. The former writers remark: “The movements by which the great brecciated masses were aggregated were clearly suspended and repeated many times; the intervals of quiescence allowing of those deposits of finely, triturated red sand and marl which alternate with the coarse and subangular conglomerates. … These breccias and conglomerates, with their associated sandstones, are of gigantic dimensions, and have been bored into in fruitless searches after coal to a depth of about 2500 English feet.” (Here is surely something more than a mere appendage to the Carboniferous.)

The best test of the difficulty of an inquiry is the number of theories which its solution has evolved. If we test the subjectmatter of the present communication in this way, we shall be assured that, second only perhaps to the Loess, which has occupied us previously, it may claim pre-eminence for the difficulty of the problems which surround it. We only venture upon a tentative solution. Such a solution is in effect the only one which is available in science at all; for to-morrow's fiercer light is certain to throw out of perspective some of to-day's most cherished convictions; and finality is outside the pale of all living and fertile inquiry.

Let us see then what “the Old Masters” had to say on the subject before us. In Mantell's Geology of the South-East of England, 1833, page 28, speaking of the beds of slightly rolled flints which occur on the Downs in Sussex just underneath the turf, he says, “The flints are more or less broken, have suffered but little from attrition, and are so abundant as to form a constant supply for repairing the roads in the south-eastern part of Sussex. This bed has clearly been formed by the destruction of the upper portion of the chalk; and it is equally evident that the cause which produced the disintegration of the superior strata was as transient as it was effective, since, although the chalk in which the flints were imbedded has been entirely destroyed, the latter have sustained but very little injury.”

Since the British Eocenes, especially of the Hampshire Basin, were mapped by the Survey, a portion of them have been separated by several writers as Oligocene. The utility of the change is not apparent in our country, where the break is seen to be purely artificial; but in other parts of Europe the Oligocenes, which embrace formations previously known as Lower Miocene, are of great importance. This change, absorbing the entire Upper Eocene fromation of the Isle of Wight, would seem alone to necessitate a reconsideration of the classification of the remainder. But the classification of the Eocene formation, invented and often modified when the beds composing it were imperfectly known, is throughout arbitrary and artificial, and scarcely yet on a scientific basis. Most of the present divisions comprise under one name the very distinct deposits formed by river, sea, or estuary, though these have been brought from quite opposite directions, and are perhaps by no means contemporaneous.

Proffessor Hull's criticisms (pp. 491–5 of this volume) on a former paper of mine on the “Classification of the Permian and Trias” lay upon me the burden of a brief reply. I may say that Prof. Hull seems to suppose that the task which I had set myself was more ambitious in its scope and aim than I was conscious of; it was not my purpose “to review the whole question of the relations of British Permian and Trias” in a paper which was limited by its title to the European rocks, and from which these systems in other parts of the world were intentionally omitted. My idea was rather to give to readers of the Geol. Mag. an opportunity of forming some judgment on the results which might be fairly gathered from a digest of the opinions collected from the various members of the “Sub-Committee on Permian and Trias.” taken along with the information which exists in the literature of this subject in England and on the Continent, more especially in Germany; and to raise discussion thereupon before the assembly of the Berlin Congressin1884.

At the end of the year 1880, Dr. O. Hahn, of Reutlingen, a lawyer by calling, published a big work entitled Die Metcoriten (Chondrite) und ihre Organismen mit 32 Tafeln photographischer Abbildungen (1880, Tubingen: H. Laupp), by which he claimed to have shown the presence in meteoric rocks of sponges, corals, and crinoids. A statement of his views was read before a meeting of the Geological Society the same summer. Early this year Dr. D. F. Weinland published a paper in support of these views, Ueber die in Meteoriten entdeekten Thierreste. Illustrated with two woodcuts (1882, Esslingen: G. Fröhner). The question was thoroughly gone into in a scientific way by Prof. Carl Vogt, of Geneva, and the conclusions at which he arrived are contained in a paper entitled Les prétendus Organismes des Météorites, published 1882, Genéve: H. Georg. It is shown that Dr. Hahn had no foundation for his conclusions; that all the pretended organic structures are purely inorganic; and that in no single case do they present the microscopic structure of the organisms for which they have been mistaken — such as crinoids, corals, and sponges. See also Dr. Laurence Smith on the subject in the Amer. Jour. Sc. 1882, February, 156.