hand simultaneously with the image of the object-glass or speculum formed by the eye-piece; the diameter of that image is given at once by the divisions to of an inch, and can be readily estimated to half that value. The arrangement mentioned by "W. R." is no doubt very convenient, and quite adequate for his purpose; but for high powers I should suppose that the comparative coarseness of the engraved lines would make itself mach more felt than it is in Mr. Berthon's invention, and the balance of economy is so greatly in favour of the latter in comparison with every contrivance with which I am acquainted, that I have no hesitation in saying that it ought to be in the hands of every amateur who cares to know the magnifying power of his telescope. It may be procured for five shillings, of Mr. Tuck, watchmaker, Romsey. T. W. WEBB

New Form of Cloud

THE kind of cloud described by M. André Poey (NATURE, Oct. 19, 1871, p. 489) is by no means new or rare if I can judge correctly from the figure and explanation. It may often be seen on the lower part of the flank of a great rain or thunder cloud, and appears to arise from the dropping or subsidence of portions of the air heavily loaded with watery particles. My own impression is that it appears when the cloud is about to break up. M. Poey will find the cloud described in the Philosophical Magazine for July 1857, where the name of droplets is given to the form, and its position in a thunder cloud indicated by a figure. J.

I HAVE not read in your "Notes" any record of the earthquake which was felt at daylight of the 16th February last in this city, in two successive and gentle but decided shocks, doing no damage, but which, from the files of the Calcutta Englishman of February 18, seems to have been severe to the N. W. of this, extending through Cachar, Silchar, Gowahatty, to Calcutta and Barrackpore.

This earthquake, you will observe, is synchronous with those of the western hemisphere already recorded by you. CHARLES HALSTED Mandalay, Burmah, Sept. 1

A Plane's Aspect

66

I AGREE with Mr. Proctor that the disuse of the term "position" in geometry would be a serious misfortune; happily, however, it is not its disuse, but the prevention of its misuse which is contemplated. I cannot agree with him that "position is a word "which no one can misunderstand," for his own letter is a striking example of its being misunderstood, either by Mr. Proctor, or by others. Aspect and slope," he tells us, "indicate two elements, which, together, fix the position" of a plane. Geometers, however, certainly understand, when a plane is said to be given in position, that something more than its aspect and slope may be regarded as known. Parallel planes have necessarily the same slope and aspect, but surely not the same position. To be told that, because its slope and aspect are invariable, the plane of Saturn's rings has a fixed position in space, notwithstanding that the planet moves bodily in its orbit, would scarcely satisfy a student of astronomy accustomed to geometrical precision.

There can be no doubt that "position" is the true English equivalent of the German word "Lage," and that no ambiguity of the kind above indicated could attach itself to the term, had we a suitable English rendering for the word "Stellung." I do not consider the term "aspect" to be perfect as an equivalent for "Stellung," but I have no hesitation in admitting that Mr. Laughton's suggestion is happier than any previous one I can remember. Mr. Proctor declares his intention of opposing the

"use of the word aspect' in a sense not at present assigned nor properly assignable;" but when he wrote thus, he had not seen the letter of Mr. Wilson wherein the term "aspect" is very rigidly To me this very defined to be the direction of the normal. facility with which the word "aspect" lends itself to rigid definition, is a ground of objection against it. I have never seen Stellung defined in the manner in which Mr. Wilson has defined "aspect." Von Staudt, in whose admirable writings I first met the word, introduced it thus: "Parallel planes possess something in common, which may be regarded as appertaining to each one of them, and shall be called their 'Stellung;' the 'Stellung' of a plane, therefore, is determined by any plane which is parallel thereto, and two planes have the same 'Stellung' or different 'Stellungen' according as they are parallel to, or intersect one another."

That the term "aspect" is not sufficiently elastic to permit of its taking the place of "Stellung" in the above passage cannot, I think, be well maintained by Mr. Proctor, seeing that he has not himself hesitated to use it in two widely different senses in the following passage of his letter: "I can see no reason why 'aspect' should be regarded in a new and unfamiliar aspect." The expression "aspect of a plane," whether it be retained or not as the equivalent of the "Stellung einer Ebene," appears to me, I confess, to be much too good to be claimed by Mr. Proctor as indicative solely of the direction of the projection of the normal upon a certain plane of reference. I would suggest, in the interest of his twelve excellent books, that he might qualify aspect," as thus defined, by an appropriate adjective, for the term is there used in a very technical sense indeed, and is not even applicable to all planes. Although Mr. Proctor can assign, for example, a southerly aspect to the face of a roof which has a slope of 30°, he would find some difficulty in describing the aspect of a roof which has no slope at all, whereas Mr. Wilson would without hesitation pronounce its aspect to be vertical. Athenæum Club, Oct. 31 T. ARCHER HIRST

66

IT is due to my friend and your correspondent, Mr. Cecil J. Monro, of Hadley, to state that, to my knowledge, he was in the habit of employing the word " aspect" in this technical sense long before the publication of Mr. Laughton's letter, and I should not be surprised to learn that other geometers have used it before Mr. Monro.

I think Mr. Proctor will find few to agree with him in his condemnation of the word so used. For myself I heartily agree

with Mr. Wilson in the welcome he accords to this "old friend with a new face." C. M. INGLEBY

"In geometrical language "-I quote from Gregory's "Solid Geometry," 1845-"the position of a plane is determined by making it pass through three given points." Mr. Proctor says he "can see no reason why 'position' should be dismissed from the position it has so long occupied." No more can I. I would only call his attention to the fact that the meaning which he would assign to the word "position" is quite different from that which has been accepted, in a technical sense, by geometers, and in an everyday sense by everyday people.

Mr. Proctor's special objections to the word " aspect," rest, it seems to me, on a misconception of its meaning and familiar use. We speak of the aspect of a wall, but not of the aspect of a roof, nor of a hill. What the usage amongst builders in respect of roofs may be, I don't know, but geographers almost invariably speak of the "slope" of a hill, as, for instance, the southern slope of the Himalayas. Put into exact language, the aspect of a plane is the direction of its normal; and as parallel planes have parallel normals, any number of parallel planes have the same aspect, without reference to their position; but no two planes, parallel or not, can possibly have the same position.

The word "slope" is almost equally inadmissible; in the first place, it refers to some other plane, which is apt to cause

confusion; and in the second, although all parallel planes have the same slope, any number of other planes not parallel can also have it; the word is therefore not sufficiently definite. "Tilt," a word spoken of by Mr. Proctor, as though it had been suggested, has no geometrical meaning whatever. As a substantive it is a "tent," or "awning;" it has also been sometimes used poetically as an equivalent to " tournament," and is, I believe, the familiar These are its only meanings,

abbreviation of "tilt-hammer."

and none of them apply to a plane.

I would only add that I do not quite see what the fact mentioned by Mr. Proctor, that he has written twelve books in the

last six years-interesting as it may be from a bibliographical J. K. LAUGHTON

point of view-has to do with the matter.

Oct. 29

66

Aspect" and "slope" stand on the same footing, one connotes a reference to the points of the compass, the other to the horizon. Neither can be used in Mr. Wilson's sense without departing from their colloquial meaning, but it is perfectly competent for geometers to take a word from common conversation and give it a scientific meaning. Either of these words may be used in Mr. Wilson's test sentences. Parallel planes have the same slope, two slopes determine a direction, &c.

It is yet possible that some correspondent can suggest a better term, either one imported from ordinary life or one conceived for the purpose. THE CORRESPONDENT WHO SUGGESTED "SLOPE"

Geometry at the Universities

PROF. THISELTON DYER has well pointed out a distinction

which exists between the mathematical courses at Oxford and

Cambridge. But his conclusion, that at Oxford " special attention to geometrical methods would pay very well," though acceptable in its way, falls far short of what I advocate. The great want at both Universities is a course of geometrical studies; and the proof that such a want exists is to be found in the fact that the geometrical treatises in use at either University, cover so very limited a range. There are not even any text-books on the geometry of the sphere, cone, cylinder, and like simple solids, or on such curves as the lemniscate, cycloid, and the simpler spirals. A few stray notes on these subjects may be found in some of the text-books, but not a thorough and systematic geometrical investigation of any of them. Geometrical treatises might with advantage range much further. A geometrical treatise on ellipsoids would be of immense use apart from its employment as a means of mental training. Geometrical treatises on paraboloids of both kinds, on hyperboloids of one sheet and of two sheets, on the various orders of ring-surfaces and screw surfaces, and on many other tridimensional matters, would afford invaluable exercise to the student, besides having a real value to the scientific worker. I venture to express my conviction, that a course of such studies would tend to develop mathematical powers much more thoroughly even than the study of covariants and contravariants, Jacobians, Hessians, et hoc genus omne.

If there is one department of mathematical research in which our countrymen are fitted by their mental habitudes todistinguish themselves pre-eminently, it is precisely this neglected department of geometrical research. As it is, though we have geometricians of great power, no systematic geometrical work is done in England. Our treatises lange only over the most elementary geometrical subjects, and even in discussing these subjects our writers are fain to accept the assistance of Continental geometricians. One would conceive that each of our Universities might yearly send out many who could treat of the elements of geometry without keeping a hand always on some French or German text-book. Brighton, Oct. 27 RICHD. A. PROCTOR

DEEP-SEA DREDGING IN THE GULF OF ST. LAWRENCE

THE marine zoology of the deeper parts of the River and Gulf of the St. Lawrence has not been investigated until quite recently. This summer, under the auspices of the Natural History Society of Montreal, and in consequence of the kindness of the Hon. Peter Mitchell, Minister of Marine and Fisheries for the Dominion (who not only gave me facilities for dredging on board Governfor the purpose), depths of from 50 to 250 fathoms were ment vessels, but also caused sufficient rope to be provided successfully examined. The greatest depth in the Gulf, to the west of the Island of Newfoundland, as given in the Admiralty charts, is 313 fathoms. It is thought that a general sketch of the results obtained may be of interest to the readers of NATURE.

The cruise lasted five weeks, the first three of which dienne, and the remaining two on the Stella Maris. The were spent on board the Government schooner La Cana

area examined includes an entire circuit round the Island of Anticosti, and extends from Point des Monts (on the north shore of the St. Lawrence) to a spot about half way between the east end of Anticosti and the Bird Rocks. As these investigations were almost necessarily subordinate to the special duties on which the schooners were engaged, in several cases the same ground was gone over twice.

The bottom at great depths generally consists of a tough clayey mud, the surface of which is occasionally dotted with large stones. So far as I could judge, using an ordinary thermometer, the average temperature of this mud was about 37° to 38° Fahrenheit, at In the deepest parts of the river, on the south shore, between Anticosti and part of the Gaspe Peninsula, the thermometer registered a few degrees higher. Sand dredged on the north shore in 25 fathoms also made the mercury sink to 37° or 38°.

least on the north shore.

Many interesting Foraminifera and Sponges were obtained, but as yet only a few of these have been examined with any care. A number of Pennatulæ were dredged south of Anticosti; the genus has not been previously recorded, so far as I am aware, as inhabiting the Atlantic coast of America. They were found in mud, at depths of 160 and 200 fathoms, and it seems probable that this species, at least, is sedentary, and that it lives with a portion of the base of the stem rooted in the soft mud. Actinia dianthus and Tealia crassicornis were frequent in 200 to 250 fathoms. The Echinoderms characteristic of the greater depths are a Spatangus (specifically distinct from the common British species), Ctenodiscus crispatus, Ophioglypha Sarsii (very large), Ophiacantha spinulosa, and Amphiura Holbollii. Marine worms, of many genera and species, were both numerous and fine. Among the more interesting of the Crustacea were Nymphon grossipes (?) Crustaceans were taken at a depth of 250 fathoms, enand a species of Pycnogonum. Several of the last named tangled on a swab, fastened in front of a deep-sea lead, which was attached to the rope, a few feet from the mouth of the dredge. This circumstance tends to show that the genus is not always parasitic in its habits. The Decapods, Amphipods, &c., at least those of greatest interest, have not yet been identified. Among the most noticeable of the marine Polyzoa are Defrancia truncata, and what appears to be a Retepora. Not many species in this group were obtained in very deep water, and those procured were, for the most part, of small size. About six species of Tunicates were collected. Being anxious to have Mr. J. Gwyn Jeffreys' opinion upon the various species of Mollusca during his visit to Montreal, I studied these carefully first, and submitted the whole of them to him for examination. Twenty-four species of Testaceous Mollusca were obtained at depths of from 90 to 250 fathoms. Nearly all of these are Arctic forms, and eleven of them are new to the continent of America.

The following are some of the most interesting of

the deep-water Lamellibranchiata:- Pecta grænlandicus of Chemnitz, but not of Sowerby; * Arca pectunculoides Scacchi; Yoldia lucida Loven ; Y. frigida Torell; Neæra arctica Sars; N. obesa Loven. Among the novelties in the Gasteropoda of the same zone are the subjoined :-Dentalium abyssorum Sars; Siphonodentalium vitreum Sars; Eulima stenostoma Jeffreys; Bela Trevelyana ;* Chrysodomus (Sipho) Sarsii.* Three Brachiopods occur in the Gulf, of which Rhynchonella psithacea and Terebratella Spitzbergensis are found in about 20-50 fathoms, and Terebratula septentrionalis in from 100-250. A few rare shells were obtained in comparatively shallow water; among them an undescribed Tellina (of the section Macoma), a new Odostomia, and Chrysodomus (Siphho) Spitzbergensis* Reeve. Nor were even the Vertebrata unrepresented; from a depth of 96 fathoms off Trinity Bay, a young living example of the Norway" Haddock" (Sebastes Norvegicus) was brought up in the dredge. And off Charleton Point, Anticosti, in 112 fathoms, on a stony bottom, two small fishes were also taken; one, a juvenile wolf fish (Anarrhicas lupus) the other a small gurnard, a species of Agonus, probably A. hexagonus Schneid.

The similarity of the deep-sea fauna of the St. Lawrence to that of the quaternary deposits of Norway, as described by the late Dr. Sars, is somewhat noticeable. Pennatulæ, Ophiura Sarsii, Ctenodiscus crispatus, several Mollusca, &c., are common to both; but on the other hand, the absence of so many characteristic European invertebrates on the American side of the Atlantic should be taken into consideration. The resemblance between the recent fauna of the deeper parts of the St. Lawrence, and that of the Post-pliocene deposits of Canada, does not seem very close, but our knowledge of each is so limited that any generalisations would be premature. J. F. WHITEAVES

ON

THE REDE LECTURE AT CAMBRIDGE NE of the indirect results of university reform has been the establishing at Cambridge of the Rede Lecture, one of the highest intellectual treats of the whole year, as will at once be acknowledged when the names of the distinguished persons who have delivered it since its establishment in 1858 are known -viz., Professors Owen, Phillips, Max Müller, Willis, Ansted, Airy, Tyndall, Miller, Ruskin, Huggins, General Sabine, Sir W. Thomson, and Mr. Norman Lockyer. For many years past there had been certain lecturers at various colleges, whose duty it was to deliver lectures on mathematics, philosophy, rhetoric, and logic; but in 1858 the endowments for these lectures (originally given in 1524 by Sir Robert Rede, Chief Justice of the Common Pleas in the reign of Henry VII.) were amalgamated, and the result has been the delivery once a year of the Rede Lecture by some distinguished man of science chosen by the Vice-Chancellor for the time being. Such is the history of the benefaction; but it must now be added that as the remains of this distinguished man lie in a village church in Kent, that of Chiddingstone, near Eden Bridge, in which parish he lived and died, without a memorial or inscription of any kind over his grave, it is proposed to do for him what Cicero did for the unhonoured grave of Archimedes, and an effort is, therefore, being made to mark his place of burial by erecting a window of stained glass in the chancel that he built. The cost of the memorial, with suitable inscription, cannot be less than 160/., but nearly 70l. has been raised by subscriptions from the distinguished persons who have delivered the lecture, and by other friends, members of the university and otherwise-viz., the Earls of Powis, Derby, and

I am indebted to Mr. Jeffreys for the identification of species to which an asterisk is attached. He corroborates also my determination of the remainder.

Strathmore, the Vice-Chancellor, the Masters of Jesus and Clare Colleges, the Provost of King's, Professors Selwyn and Sedgwick, Mr. Beresford-Hope, M.P., Sir John Lubbock, M.P., the Public Librarian, Rev. W. H. Latham, and J. Brocklebank, with many others; but the amount thus subscribed, together with the local effort, is inadequate for the full completion of the memorial, and it is hoped that there will be some others who will be willing to help on the work. Mr. Norman Lockyer, F.R.S., the present holder of the office of Rede Lecturer, has kindly consented to receive subscriptions at 6, Old Palace Yard, Westminster.

It is proposed to erect the following inscription, from the pen of Professor Selwyn, who will receive any subscription forwarded to him at Cambridge.

THE CONJOINT EXAMINATION SCHEME* THE HE proposition carried at the last meeting of the Council of the College of Surgeons clears away, we suppose, the last difficulty in the way of an amalgamation between the Colleges of Physicians and Surgeons for the purposes of examination and of issuing diplomas. It is remarkable that the College of Surgeons should have come back to the original proposal, though it was at first demurred to and given to a committee for consideration. The College of Physicians, at its Comitia on Thursday, finally agreed to this proposal; and it now only remains for the General Medical Council to give its consent under the Medical Act of 1858, so as to allow of the fusion in question.

In order to get at the practical working of the proposed scheme of division of fees, we may take the present income of the College of Surgeons from the membership diploma, adding 10l. for each diploma issued to represent the additional fee to include the College of Physicians. The sum produced by the membership diploma during the last financial year was close upon 8,000l.; and if we add 10/. for each of the 291 diplomas issued, we have in round numbers the sum of 11,000l. The proposed scheme is, that one-half of this should be devoted to all the expenses of the examinations, and that the remaining moiety of 55,000l. should be divided into thirds. One-third is to go to the support of the Museum of the College of Surgeons and its unendowed professorships, one-third for the maintenance of the personnel of the College of Physicians, and one-third similarly to that of the College of Surgeons. This will give the Hunterian Museum and each of the Colleges some 1,800l. a year apiece, irrespective of other sources of income. With this income, it will, we imagine, be perfectly possible to carry on satisfactorily the establishments in Pall Mall and Lincoln's Inn Fields, if due economy be observed and proper supervision exercised over the subordinate officials. The Hunterian Museum will be upon a somewhat shorter allowance than heretofore; but if this prove insufficient, Parliament must be appealed to for a grant in favour of what the Council of the College of Surgeons properly characterises as an "institution of national as well as professional importance."

*Reprinted from The Lancet.

THE

SIR RODERICK MURCHISON

HE life of a scientific man is for the most part uneventful, and perhaps to the world at large uninteresting. That he was born, lived a certain number of years, and died, are often the chief facts chronicled of the man himself. Of his work and of the influence of his work men are willing to read, but for the story of his life, with its quiet everyday monotony, they care little. Yet it is true, at least of the higher type of mind, that the story of the man's life and the history of the work he accomplished are inseparably connected, and are each necessary for the understanding of the other. There arise, too, ever and anon instances when the man was not merely a man of science, but one whose scientific career formed as it were a nucleus round which many other and often divergent interests gathered. Such a man's life is sometimes

linked in so many ways with that of the society in which he lived, that its chronicle becomes in some degree the history of his time. And such a man was Roderick Impey Murchison. By no means standing on the highest platform of scientific intellect, a patient gatherer of facts rather than a brilliant generaliser from them, he yet gained by common consent in the commonwealth of science the position of a king, under whom men of all ranks, and even men of far higher ability and attainment than his own, were not only willing but delighted to serve. He held a place which no other man of science left among us now fills. It was not merely his achievements in geology, memorable as these were, which gave him that proud pre-eminence, nor did he owe anything to success in other branches of science, for he seldom travelled beyond what he knew to be his proper domain, nor to graces of literary style, on which men of slender acquirements often float

into popularity. He wrote only on geological and geographical subjects, and in a solid matter-of-fact way not likely to attract readers who did not previously care for his subjects. It was his personal character, his nobleheartedness, his indomitable energy, his tact and courtesy, the dignity and grace which he never failed to show even to opponents, and the social position which his family and fortune gave him, and which enabled him greatly to extend the respect shown in society to science and scientific men, -it was these causes which largely went to make Sir Roderick's influence what it was. A narrative, to do him justice, should tell how these causes came into play, and how, combined with the regard which he could always claim for his solid contributions to science, they placed him so high in the scientific circle in which he moved. Murchison was born on February 19, 1792, at his

father's little estate of Tarradale, in Eastern Ross shire. He used to speak with fondness of the fact that he first saw the light amid those old palæozoic sandstones, conglomerates, and schists, on which he was afterwards to rest part of his title to fame. Yet it was not among the wilds of Ross that he acquired a love for rocks. He was removed from his birthplace at an early age, and taken into Dorsetshire, and though when still a child he was brought back into Scotland, and remained with his mother at Edinburgh for a short while, it was in England that he spent most of his boyhood, and where he was educated. At the age of fifteen he obtained a commission in the 36th Regiment of Foot, and served in the Peninsula under Sir Arthur Wellesley. He carried the colours at the Battle of Vimiera, and went through much hardship in the retreat of Corunna. At the end of the war,

after having become a captain of dragoons, he quitted the army, and marrying the daughter of General Hugonin, settled in England. So ended what he used to call the military episode of his life. Next came the foxhunting period, when his activity of disposition found vent in the excitement of the chase, into which he threw himself heart and soul. He might have continued a merry, hearty, sporting, country gentleman, but for the influence of his wife, who was fond of natural history pursuits, and the advice of Sir Humphrey Davy, who, meeting him at the house of Mr. Morritt, of Rokeby, and seeing in him promise of something better than foxhunting, advised him to attend the Lectures of the Royal Institution. Sir Roderick used to tell an interesting anecdote of that early beginning of his scientific career. He was attending the lectures of (if we remember) Dr. Brande, when one day the lecturer's place was taken in his absence by a pale thin lad, his assistant, who gave the lecture and experiments in so admirable a manner as to be received at the end with a hearty round of applause. It was Michael Faraday, and this was his first public appearance.

After gaining considerable knowledge from public lectures and private instruction, Sir Roderick's active mind sought as early as possible to study Nature in the field. Geology was the branch of science which suited best a nature so fond of out-of-door life as his. He had made the acquaintance of William Smith, the father of English Geology, from whose own lips he had learned the order of succession which the marvellous patience and ingenuity of that pioneer of the science had made out for the rocks of England and Wales, and indeed, as was afterwards found, for the rocks of all the world. In the year 1825, when he was thirty-three years of age, he wrote his firstpublished paper, "A Geological Sketch of the Northwestern Extremity of Sussex and the adjoining parts of Hants and Surrey." From that time onwards for nearly half a century he continued to furnish accounts of his observations in the field. Beginning, as was natural, with the district in which he lived, he soon extended his researches even as far as his own native Highlands, then step by step over the Continent of Europe, even as far as the confines of Asia. He has published more than 100 memoirs on British and Continental Geology, besides numerous addresses to scientific societies, and in addition to upwards of twenty memoirs in conjunction with other authors. To all this mass of work must be added what he published in separate volumes -his great "Silurian System," his splendid volumes on "Russia," and the successive editions of his "Siluria."

Of the incidents of his life during its scientific period it is not necessary here to say much, nor to try to count up the honours showered on him from all parts of the world. There was hardly a scientific Academy anywhere which had not enrolled him among its associates, and to the dignities conferred on him by his own Sovereign, were added others conferred by Emperors and Kings abroad. His time was largely passed in London, where he took an active share in scientific work. But every year he made a tour either in this country or on the Continent, and added to our knowledge of the geological structure of the districts which he visited. Sometimes these tours were prolonged, and in the case of his Russian campaign he was absent for two or three years from England.

At the time when Murchison broke ground as a geologist, the science of geology had entered a new phase of its history. The absurd system of Werner, though still upheld by high authority in this country, was daily losing ground, and the simple and obvious classification of William Smith on the one hand, and the doctrines of Hutton on the other, were guiding all the younger intellects of the day. Murchison's tact is nowhere more conspicuous than in his choice of a field for the exercise

of his patient energy of research. He saw that the old Wernerian notion of "transition " rocks was doomed, and that it would be a task well worthy of his time and toil to unravel the succession of these rocks, and try to introduce into them the same order and consistency which Smith had shown to mark the Secondary series of England. He chose for the scene of his researches the border country of England and Wales, where these old rocks are well displayed, and after five years of unremitting labour he produced his "Silurian System "-a work, which, though dealing only with the rocks of a limited tract of Britain, yet first unfolded the earlier chapters of the history of life upon our globe. The classification he adopted, though of course necessarily subject to local variation and change, has been found to hold true on the great scale over the whole world.

This work laid the foundation of Sir Roderick's fame. In his subsequently published "Siluria," which has gone through several editions, he recast the original work, introducing much detail regarding the extension of Silurian and older paleozoic rocks into other countries; but while in the later publication, the results given were necessarily often the work of other observers the "Silurian System" remains a monument of the unaided labour of a mind quick in observation, sagacious in inference, patient in the accumulation of data, and full of that instructive appreciation of the value of facts not yet understood, which is near of kin to genius.

It would be beyond the limits of this journal to offer an adequate outline of Sir Roderick's scientific work. He was distinctly and specially a geologist. His early attachment to paleozoic rocks never waned, and though now and then he was led to make and record observations on later formations, he always returned to the older deposits as his natural inheritance and domain. He was not a paleontologist, but no geologist could use more skilfully than he the data furnished by paleontology. This faculty he acquired at the beginning of his career, and it marked all his work in the field both at home and abroad. It enabled him to apply to distant countries the principles which he had so successfully used in his own. Perhaps the leading idea of his scientific life should be regarded as the establishment of the order of succession among rocks. This was what he did in the Silurian region originally, and what he always endeavoured to ascertain in every district to which choice or accident might lead him. He had a singularly quick eye for the geological structure of a country. No one who travelled with him through a hilly tract, and, after listening to his rapid inferences, has gone actually over the ground to see, could fail to be struck with the accuracy with which he seized on some of the leading features, and from these deduced the general arrangement of the rocks. It was in this way, and by the use of paleontological evidence, that he was enabled to arrive at one of the most brilliant generalisations he ever achieved, when he brought order and intelligibility into the chaos of the so-called primary rocks of his own Scottish Highlands-a deduction which is, perhaps, destined to bear fruit of which he never dreamed, in the still obscure subject of metamorphism.

Sir Roderick Murchison's early training in geology was acquired at a time when men believed in periodic cataclysms, by which the surface of the globe was destroyed and renewed. He never could, and he never seemed seriously to try, to shake himself free from the influence of that training. Though he modified his views as years went on, he remained a member, and indeed in this country the leader, of the Cataclysmic School. The upholders of a long line of successive creations and of the former greater intensity of all geological causes have lost in him one of their ablest, staunchest, and most influential associates.

To the world at large, however, it was not from his geological work chiefly that Murchison was known. His