consist of blue clay slate, not differing, in | he can do that, however, he must learn to any essential character as a kind of rock, recognise the general characters of the from the slates found in the old Palæozoic groups of fossils, and as many of the characrocks of our part of the world. These terms teristic species as he can. The formations then necessarily lose all their original litho- of any period will consist of different kinds logical significance, and are to be under- of stratified rocks in different localities, stood in a chronological sense. In speak- and may consist of any kind whatever, or ing of Cretaceous rocks, we mean merely may be associated with any description of rocks that were consolidated in that great igneous rocks; while they can only conperiod during a part of which the chalk of tain the remains of such animals and plants Europe was formed, and so of all other as lived during the time when they were deposited.

the mind amused, but with the muscles in- | done, and the great practical value and vigorated, the nerves braced, and the utility that would be obtained if surveys, blood coursing through the veins with that still more detailed, and on a systematic pleasurable glow that makes every breath plan, were to be undertaken. This could we draw a pleasure in itself while good only be accomplished at the public exdigestion waits on appetite, and health on pense. Some of the European Governboth.' ments, and, still earlier, some of the United States of America, ever foremost in works of practical utility, established state or government surveys: some of our own colonies followed the example, and at last the British Government, at the instance of Sir H. T. De la Beche (and after he had commenced the work at his own labour and cost), founded a Geological Survey, which has since grown into an institution, which appears likely to become permanent. Since then Canada, India, Australia, the Cape of Good Hope, and other places, have commenced or extended their geological surveys, chiefly under officers trained in the school of the mother country.

As regards maps, the novice in this country will find the guide he requires in the beautiful map of England and Wales, by Professor Ramsay, which contains, in a condensed form, the result of the labours of many men, continued through half a century. It has all the latest discoveries, is excellently coloured, and of a scale just large enough to be distinct. The smaller map, by Sir R. I. Murchison, is equally good in execution, but from its smaller scale not quite so serviceable as that of Professor Ramsay. For a glance over the structure of Scotland, we may take as our guide the very useful map published by Professor Nicol. Excellent as it is, however, it has to our eyes some drawback in its colouring, since he makes the Old Red Sandstone of Scotland a pale dirty green, and indicates the Coal-measures by a minute cross-hatching, which it is torture to the eye to look through in search of the names, and which is moreover scarcely distinguishable, either in colour or character, from that employed to indicate Chlorite slate. The geology of Ireland has been most admirably delineated so far as the labour of one man, with but little assistance, could accomplish such a vast work, by the maps of Sir Richard Griffith. The last edition of his large map will be an enduring monument to his name; and a small and cheap edition which he has published is well adapted to give a general notion of the structure of Ireland. Maps of sufficient accuracy to enable us to give even a slight outline of the structure of the British Islands, were the result of the labours of many men for many years. M'Culloch laid the foundation in Scotland; Weaver and Portlock, and others, had laboured in Ireland both before Griffith and contemporaneously with *We believe that some of the districts of the him. Greenhough, in England, had comnorth of England and of Scotland will shortly be bined with his own explorations the re-coloured, and that two sheets of the one-inch map published on the six inch scale, geologically sults of those made by W. Smith, Fitton, of Scotland are nearly ready for issue. Conybeare, Buckland, De la Beche, Phillips, Sedgwick, Murchison, and many more. Similar maps, more or less complete, had been published abroad by equally enthusiastic cultivators of the science. Still it was felt that this was not enough. The maps and the descriptive memoirs thus put forth by individuals, or by societies, only showed what might be

The Geological Survey of the United Kingdom is conducted under the powers of an Act of Parliament passed in the 8th and 9th year of Victoria (1845). Sir H. T. De la Beche, the first Director-General, was succeeded by Sir R. I. Murchison in 1855. It is divided into two branchesthe survey of Great Britain, under the local directorship of Professor A. C. Ramsay, and that of Ireland, now under Mr. J. Beete Jukes. In Ireland and in those parts of Great Britain which have been laid down on the scale of six inches to the mile, the field observations are inserted in the maps, while the results are published by means of geologically-coloured copies of the maps on the scale of one inch* to a mile, accompanied by printed explanations and memoirs. The amount of labour expended on these works can only be rightly understood by the field geologist. If any one wishes to put it to the test, we recommend him to take one of the maps of North Wales, and try, among the rugged precipices of Cader Idris or Snowdonia,†

The only man capable from his own knowledge of forming a judgment on the maps of North Wales was Professor Sedgwick. He had, unassisted, except by his own inexhaustible bodily energies, keen perceptive faculties, and sagacious grasp of intellect, unravelled all the intricacies of the mountainous districts of North Wales and the Lakes (to say nothing of other regions), and had in his mind as perfect a model of those countries as could be constructed by any surveyors. In North Wales indeed he was, in some of his conclu

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to trace out by its guidance the complica- | work requiring a combined action, each tion of intrusive and contemporaneous man must be confined within a certain disigneous rocks, and their associated ashes' trict until he has completed its examinaor tuffs, variously interstratified with tion, and carefully recorded everything different kinds of aqueous rocks, and to that is to be seen in it; while there are follow these multiform and often irregular other problems which can be solved only structures through all the complex intri- by rapid motion over a whole region, or cacies of flexure and contortion, fracture even regions, for the purpose of examinand dislocation, into which subsequent ing widely-separated points, and compardisturbances have thrown them, and over ing quickly the rocks and fossils of differall the abrupt declivities of mountain, val- ent countries, so as to bring into one view ley, and ravine, which subsequent denuda- the scattered facts belonging to one class tion has worn in them. Or if he has not of objects. nerves and sinews for such a task as this, let him take one of the maps of a lead or copper mining district, and examine the net-work of gold lines that represent the mineral veins; or a map of a coal district, and study the convoluted black lines that mark the out-crops of the various beds of coal, and the numerous white lines that cut across them and represent the faults which dislocate them, and he will begin to acquire some notion of the labour, and patience, of which the colours and marks on the maps are the external signs. Whatever errors of detail may here and there exist in the earlier sheets, either of Great Britain or Ireland, will, doubtless, disappear hereafter, when the enlarged experience acquired in the progress of the task can be brought to bear on their revision. Such a work as this, indeed, is almost endless. Even could we look forward to the completion of a Geological Survey in the most perfect manner possible, there would still be need for an establishment in which to preserve the vast mass of records that will have been accumulated, and of practised officers familiar with them, ready to give to every applicant the precise piece of information he requires.

Necessary, however, and inevitable as we consider Government Geological Surveys, they will never supersede individual investigation. Their especial duty is to accumulate data that it would be impossible for individuals to procure, in consequence of the great time required to be expended on them. There are many problems, both in geological physics and in paleontology, of which it is no part of a Government Survey even to undertake the investigation. It is obvious that, in a

sions, more accurate than the first work of the survey. All geologists must ever regret that the failing health of subsequent years has prevented this hva dvoor from doing that justice to his earlier labours which they so richly deserved, while no geologist can forget him as one of the ablest pioneers of the science, as well as its most eloquent and spirit-stirring expounder.

This individual research is necessary even for descriptive geology itself, and gives a special value to such books as Sir R. I. Murchison's 'Siluria,' of which we have now to hail, with pleasure, the appearance of a third edition. We expressed our opinion of the excellence of this work when it first appeared, and its supreme importance to geologists who were engaged in investigating the Paleozoic, and especially the Lower Paleozoic rocks. The improvements introduced in the last edition have almost made it a new work. In addition to the results of his own personal investigations, Sir Roderick has now supplied an abstract of the most recent labours of the Geological Survey, together with information gathered from almost every quarter of the globe. He has himself re-examined his native Scotland. The latest work of Ramsay, Aveline, and Salter, in Wales, appears in it, as well as the newest information on Ireland. Professor Ramsay has contributed a condensed classification of the Palæozoic rocks of America; Messrs. Salter and Morris a most valuable catalogue of Lower Palæozoic fossils; Mr. A. R. C. Selwyn has given very interesting matter from Australia; Sir W. Logan from Canada, and many of the first authorities from different parts of the continent and other quarters of the globe. The mass of matter contained in this book is, indeed, so enormous, that it would be impossible for us here to give an idea of it. It requires close study on the part of a professed geologist, and must then remain with him as a book of reference for constant use.

Sir R. I. Murchison is a singular instance of a man who, having passed the early part of his life as a soldier, never having had the advantage, or disadvantage as the case might have been, of a scientific training, instead of remaining a fox-hunting country-gentleman, has succeeded by his own native vigour and sagacity, untiring industry and zeal, in making for himself a scientific reputation

that is as wide as it is likely to be lasting. | loured in this beautiful fashion, and their He took first of all an unexplored and dif- cost reduced at the same time that their ficult district at home, and, by the labour value would be increased? The best of many years, examined its rock-forma- specimen of a chromo-lithograph map tions, classed them in natural groups, as-published in Britain is that of Yorkshire signed to each its characteristic assem- by Professor Phillips-a most excellent blage of fossils, and was the first to deci- pocket map for any one who wishes to expher two great chapters in the world's plore the geology of that interesting geological history, which must always county. henceforth carry his name on their titlepage. Not only so, but he applied the knowledge thus acquired to the dissection of large districts, both at home and abroad, so as to become the geological discoverer of great countries which had previously been terræ incognitæ.'

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The little map of a small part of Sweden, round the neighbourhood of Upsala, by Mr. Axel Erdmann, is remarkable, because, unlike most other geological maps, it delineates not only the solid rocks, but all the different matters that occur between the upper surface of those rocks With such a training he was well en- and the actual vegetable soil; so that we titled to publish the Geological Map of see the areas occupied not merely by Europe, which he put forth some time ago peat,' but by moss not yet converted in conjunction with Professor Nicol. Af into peat,' by 'shell marl,' 'infusoria clay,' ter the appearance of the beautiful Geolo-'alluvium,' black fucus marl,' stratified gical Map of Russia, which accompanied clay,' 'fir-tree sand' (as it is called), 'anhis second great work (that on Russia gular gravel,' and 'rolled gravel,' the and the Ural Mountains'), he had enclosed solid rocks rising only here and there like Europe, as it were, on two sides, in a islands through these various superficial frame of his own handiwork. He had, deposits. Such information must be most moreover, harmonised the work of many valuable to the agriculturist, and it will other observers and combined it with his remain for the Geological Survey of the own, with respect to more recent forma- United Kingdom to undertake the contions in the centre and south of Europe, struction of similar maps of the superficial in his paper on the structure of the Alps, deposits after the record of the formations Apennines, and Carpathians, published in beneath them has been completed. the Journal of the Geological Society." His map bears the date of 1856; the other map of Europe, which we have mentioned in the list at the head of this article, is, unfortunately, without a date. It was compiled by the late M. Dumont, the excellent geologist of Belgium. In the great outlines the two maps agree, as must necessarily be the case if they be correct; in portions of the details there are differences, and in some of these the English work is, we think, the more correct of the two. The Belgian map, however, is on a rather larger scale, and in many places is more minute; while, as to the beauty, distinctness, and permanence of the colouring, the map of Dumont not only excels that of Sir R. I. Murchison, but is, beyond all comparison, the best coloured map we ever remember to have seen. The various colours are so clear and sharp, that no overlapping can be detected, even by the lens when applied to dots not larger than a pin's point, or to small spaces having the most sinuous and deeply-indented outlines. Why is it that equally good lithographic colouring is not produced in Britain, and applied to our own maps? why, above all, should not the maps of the Geological Survey a great national work-be co

Of the United States of America and the British American colonies the most recent results are contained in Sir W. Logan's 'Reports on the Survey of Canada for the years 1853 to 1856,' and Professor Rogers's 'Geology of Pennsylvania.' The method to be pursued in a partly-uninhabited country, of which no complete topographical map exists, must necessarily be very different from that adopted in older lands, fully opened by roads and accurately delineated. Sir W. Logan has accordingly been compelled in many cases to confine his observations to the borders of rivers and lakes, where alone they could be made with accuracy and their locality precisely determined, while he has as yet been unable to construct a general map of sufficient correctness to receive his observations, though one is said to be in process of completion. The reports, however, contain many detached remarks of value to the geologist, and teach him what to expect when the remainder shall be published.

Professor Rogers's 'Geology of Pennsylvania' is a most remarkable work. It is called a Government Survey, and it was commenced and partly carried on under the auspices of the State, and at the public

expense. Owing to the vacillation, how- | tical as well as literary side, how impossiever, which too often characterises assem- ble he finds it to master both! If he buries blies of men ignorant alike of the theore- himself in a library or museum, surrounded tical value and the practical importance of by books, maps, papers, and specimens, scientific research, the funds were more how often he longs to examine facts for than once withdrawn from the under- himself in the field,' and finds time, and taking, and Professor Rogers was at last distance, and money alike difficulties in his compelled to complete it chiefly at his own path! If, on the other hand, he be a field expense. Maps, sections, drawings, dia- workman, how deficient he often finds grams, and figures of fossils, besides de- himself in the knowledge of what others scriptions of countries and rocks enough have recorded in books! The very sight to fill three great quarto volumes of letter- of a thick quarto is enough to appal any press, are all the work of Professors H. D. one who has but snatches of time at his and W. Rogers. When we reflect that disposal. Geological works become so they had to deal with a country containing numerous, that even professed geologists about 44,000 square miles (or only about must need despair of reading them all; 6000 less than England and Wales), tra- therefore we would, above all things, beversed by a complicated mountain range, seech geological writers to study condencomposed of a very varied series of rocks, sation. Doubtless, each may say with thrown into a wonderfully complex form, Horace, 'Brevis esse laboro, obscurus fio,' we shall be able in some degree to appre- but we do not mean so much brevity of ciate the amount of their labours; espe- expression as selection of matter. Minute cially when we also remember that, like details are in many cases necessary for Sir W. Logan, they had often to make those who may wish to follow the writer their own maps of the surface before they in all his steps, but those persons must be could even commence their more proper few compared with the increasing number labours of representing upon them the of such as wish merely to grasp the leading boundaries of the rocks below. It is truly points, and to acquire a general notion of a noble work, and will form an enduring the country, rocks, and fossils. It will be monument to the ability, as well as to the for the interest then, we think, of future perseverance and public spirit of the au- geologists to make a careful abstract of thors. The sole objection we have to their observations, whether for the use of make is to that fantastic nomenclature men of science or ordinary inquirers, and which no person, we think, except Profes- keep distinct the details which may be sor Rogers, will ever dream of adopting. necessary for the few. This opinion has We hope that he will take the earliest op- been forced upon us while examining the portunity of laying aside a façon de par- books enumerated at the head of this artiler' of which the result is to render himself cle; and we have often felt inclined to partially unintelligible to the geologists of paraphrase St. Augustine's exclamation on the rest of the world, and to throw around Persius, and say 'Si non vis legi, non him a barrier of isolation which separates potes intelligi.' him from his brethren of the hammer.

The reports hitherto received from the Geological Survey of India have been brief and detached; but this may well be excused, when we consider the size of the country to be examined and the circumstances under which it has been lately placed. The surveys of the Australian colonies, especially that of Victoria, under Mr. Selwyn, have already been fruitful in results of the highest interest to the man of science, and of daily-increasing value to the inhabitants of the countries examined. Tasmania is about to be surveyed by a young geologist, the son of the eminent ornithologist, Mr. Gould.

Ars longa, vita brevis est:-Who is there that takes up any pursuit in earnest who has not this aphorism always recurring to his thoughts? If he is engaged in a science which, like geology, has its prac