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THURSDAY, MARCH 3, 1892.
beginning with Herodotus, Plato, and Skylax, to the supposed nature of the sea-bottom. The sagacious remarks on the subject by the Italian naturalists, who were
the real founders of the science of geology in the fifteenth DEEP-SEA DEPOSITS.
century, receive appreciative notice; and the earliest Report on the Scientific Results of the Voyage of H.M.S. attempts to deal with the deposits of the deep seas, espe
“Challenger” during the Years 1873-76, under the cially those of Soldani, Ehrenberg, Sir Joseph Hooker, command of Captain George S. Nares, R.N., F.R.S., Edward Forbes, and Prof. J. W. Bailey, have full reand the late Captain Frank Tourle Thomson, R.N. cognition. The important memoir of Prof. W. C. Prepared under the Superintendence of the late Sir C. Williamson on the mud of the Levant is noticed ; but Wyville Thomson, F.R.S., and now of John Murray, the authors seem to be scarcely aware how many of the LL.D., Ph.D., &c., one of the Naturalists of the Ex- later discoveries in this branch of science were forepedition. Report on Deep-Sea Deposits, based on the shadowed in the remarkable monograph of the ManSpecimens collected during the Voyage. By Johnchester Professor. A general account of the results Murray, LL.D., Ph.D., and the Rev. A. F. Renard, obtained by the chief expeditions fitted out for the study of LL.D., Ph.D., Professor of Geology and Mineralogy in the deep ocean and its deposits—expeditions which prethe University of Ghent. Pp. xxix. and 496 ; with 43 ceded and followed that of the Challenger-leads up to Charts, 22 Diagrams, and 29 Lithographic Plates. a division of marine deposits into “Terrigenous" and (London : Published by Order of Her Majesty's Govern- “ Pelagic," a classification which, if not too rigidly ment, 1891.)
applied, appears to be serviceable and even necessary. G EOLOGISTS have had to wait long for this very The first chapter is devoted to the various methods of
important work, but now that it lies before them, obtaining, examining, and describing deep-sea deposits, we believe that the general verdict will be that it was and here the general arrangements made on board the worth while to wait even sixteen years for a monograph Challenger, which are familiar to most readers from the so excellent in design and so complete in execution. It description given by Sir Wyville Thomson in his “ Voyage must not be forgotten, too, that much of the information of the Challenger," and the narrative volumes of the Recontained in this volume has been already given to the port, receive very full and exhaustive treatment. The scientific world-first in Mr. Murray's Preliminary Report precise account of the apparatus, illustrated as it is by on the subject, published in the Proceedings of the Royal numerous woodcuts, cannot fail to be of great value to Society ; and secondly in a series of papers written by those engaged in fitting out similar expeditions. The him in conjunction with Prof. Renard, and published in study of the methods employed in the sifting, fractional the Proceedings of the Royal Society of Edinburgh. decantation, and chemical examination of the several
It is a most fortunate circumstance that the naturalist deposits is essential to the proper understanding of the on board the Challenger, who had charge of the collection, results detailed in succeeding chapters of the work. examination, and preservation of the samples of the de- The methods of analysis employed by Prof. Brazier at posits collected by the sounding-apparatus and the dredge, Aberdeen, and by MM. Renard, Sipöcz, Hornung, and as well as of those obtained by means of the tow-nets Klement, in the laboratory of Prof. Ludwig, of Vienna, and tangles, has been able during the long period that and in M. Renard's laboratory at Brussels, are given in has elapsed since the return of the vessel to England, to full detail, and will prove of great service when the devote his attention to their careful study and description. results described in the present volume come to be In the work of dealing with this vast mass of materials, compared with those of future investigators. as the preface informs us, Mr. Murray has had the co- The second chapter consists of a series of synoptical operation of Mr. Frederick Pearcey, who accompanied tables, occupying 114 pages, in which the nature and the Expedition, and was afterwards assistant in the composition of every deep-sea deposit collected during Challenger Office, and also of Mr. James Chumley. the voyage of the Challenger is described. In each case Especially fortunate has been the circumstance that Sir the number of the station, the date, the latitude and Wyville Thomson and Mr. Murray were, in 1878, able longitude, the depth in fathoms, the temperature at the to secure the aid of the eminent Belgian petrographer, surface and the bottom are given ; and these particulars Prof. Renard, who is so great a master of those micro- are followed by (1) a general description of the material scopic methods of research which have played no unim- brought up ; (2) the percentage of calcium carbonate ; portant part in the development of geological science (3) a list of the chief Foraminifera present ; (4) an enuduring recent years. In the exact determination of the meration of the other calcareous organisms ; (5) the perminute fragments of minerals which occur in these de- centage of insoluble residue ; (6) a list of the siliceous
osits, Prof. Renard's knowledge of the optical and organisms ; (7) of the minerals ; (8) a description of the chemical methods of microscopic research has proved fine washings; the last column being devoted to addiof especial value ; and the assurance that, during several tional observations. These synoptical tables are followed months in the years 1881 and 1882, the Belgian petro- by a discussion of the variation of the deposits with grapher was able to devote himself to the work of in- change of conditions along the different lines of soundings vestigating these deposits will invest the mineralogical and dredgings. This general summary of the results, determinations with an authority which they could not which occupies 36 pages of the work, constitutes an otherwise possess.
admirable résumé of the information contained in the The introduction to the work consists of an excellent tables. summary of the references contained in various authors, Chapter iii. is devoted to the description of recent
marine formations and the different types of deep-sea composed of the remains of animals on the bottom of the deposits: their composition, geographical and bathy- Antarctic Ocean. metrical distribution. All marine deposits which are not Chapter iv., dealing with the materials of organic “ Littoral,” or formed between high- and low-water marks, origin, is, we are informed in the preface, entirely from or “Shallow-water,” a term which the authors limit to the the pen of Mr. Murray. The Reports of the late Mr. interval between low-water mark and a depth of 100 H. B. Brady, of Prof. Haeckel, and of Count Castracane, fathoms, are classified in this work as deep-sea deposits. on the Foraminifera, the Radiolarians, and the DiatomThey include Coral Mud, Volcanic Mud, Green Mud, Red aceæ brought home by the Challenger Expedition, have Mud, and Blue Mud (which are classed as Terrigenous De already supplied naturalists with the means of drawing posits, formed in deep and shallow water close to land- many important deductions ; but Mr. Murray still finds masses), and the Pteropod ooze, Globigerina ooze, Diatom much to say on the subject, which is not only new, but ooze, Radiolarian ooze, and Red Clay (which are grouped of very great interest. In the couple of pages devoted as Pelagic Deposits, formed in deep water removed from to the description of those curious and abundant organland). In the case of each of these deposits the proportions isms the Coccospheres and Rhabdospheres, which Mr. and characters of the organic and inorganic materials Murray here refers without doubt to the Calcareous are given, and the results of a large number of chemical Algr, we could have wished that he had been able to analyses, some of which are now published for the first announce that he had succeeded in inducing some comtime, are discussed. Perhaps one of the most interesting petent botanist to undertake the study of the material of the many valuable discussions contained in this brought home. One of the most important discussions chapter is that which deals with the proportions of the in this chapter is that on the disappearance of calcic ocean-floor covered by different kinds of deposits. A carbonate in the deeper deposits. The estimate made map (Chart I.) is devoted to an attempt to illustrate the by Mr. Murray of the mean percentage of calcic carnature of the ocean-floor over the whole of the globe, and bonate in the different deposits, as the result of a large we cannot resist the temptation of quoting the general number of chemical analyses, is as follows:estimate to which the authors have been led by their
Percentage of CaCO3. laborious and patient researches. These results are
Coral Mud and Sand based not only on the collections made during the
79-26 Challenger Expedition, but on many obtained before and
64.53 Diatom ooze
22.96 since, which have all passed through the hands of the
Blue Mud and other Terrigenous authors; they include the materials brought up in no
deposits less than 1600 soundings from the Atlantic, 300 from the
Radiolarian ooze Indian Ocean, and 400 from the Pacific, all from depths
4'or exceeding 1000 fathoms. It is evident, therefore, that the The facts cited by Mr. Murray, on the authority of map and estimates, though admittedly only approximate, Mr. John Rathay (p. 282), on the ease with which the are based on a mass of data such as has never been remains of the Diatomaceæ are dissolved, are of especial brought together before.
importance to the geologist who is called upon to explain The total area of the surface of the globe is estimated the origin of the silica now forming nodules and bands at 196,940,700 square miles, of which dry land occupies in beds of limestone, and which he is tempted to reser about 53,681,400 square miles, and the waters of the entirely to the larger organisms like Siliceous Sponges, ocean 143,259,300 square miles. The approximate extent because remains of these are sometimes preserved. All of the areas of the sea-floor occupied by each type of the observations made in the existing deep seas, howmarine deposits is given as follows :
ever, point to the conclusion that the minute Diatoms Mean depth
and Radiolarians play a much more important part in
separating the soluble silica from sea-water than do the “ Littoral Deposits
Sili ous Sponges.
Chapter v., dealing with the mineral substances found
in deep-sea deposits, is full of interest. The mineral 2,556,800
176 Volcanic Mud 1033
particles which are obviously derived from the solid crust Volcanic Sand
of the globe are first dealt with, and in the account of Green Mud
the pumice, the basic volcanic glass, and the palagonite
of the deep-sea deposits, Prof. Renard exhibits alike his Red Mud
wide mineralogical knowledge and his skill in dealing Pteropod ooze
with microscopical and often obscure materials. The 1044 Globigerina ooze 1996 49,520,000
coloured lithographic plates illustrating this part of the Diatom ooze
1477 10,880,000 work, which have been drawn by Prof. Renard, and Radiolarian ooze 2894 2,290,000
engraved in Vienna, are of wonderful beauty and fidelity. Red Clay 2730 51,500,000
A list of mineral particles detected in deep-sea deposits Some of the most striking results, which make them- is given, and includes all, or nearly all, the common rockselves apparent from a study of this estimate and the forming minerals ; but it is admitted that, with respect to accompanying chart, are the very wide distribution of the very minute particles in the finest washings, a conthe Foraminiferal ooze and the red clay in the Atlantic siderable margin of doubt must always exist regarding and Pacific respectively; and the remarkable manner in their identification. We could wish that it were possible, which the deposits of vegetable origin replace those in the space at our command, to give a summary of the
facts leading to the conclusion that materials of extra- the work all the facts bearing upon the questions at issue, terrestrial origin play a not unimportant part in the even when they are manifestly hostile to the conclusions accumulations which are taking place on the deepest adopted. ocean-floors.
to the clear descriptions and admirable plates which illus- gratulating the editor of the Challenger Reports on trate this part of the subject. The exquisite drawings of the nearly approaching close of his heavy labours. magnetic spherules and of chondre upon Plate xxiii., Only by a worker gifted with unrivalled powers of enable the reader to judge of the real nature of the evi- organization, as well as with indomitable energy, could dence relied upon, and an examination of these figures such a task have been brought to a successful terminacannot but remove any lingering doubt, as to the true tion. The mass of materials was so vast and multinature of these materials, from the minds of all those farious, the interests involved in their distribution so who are familiar with the minute structure of meteorites. wide and often conflicting, while personal considerations
The last chapter of the work deals with the chemical could not always be kept from exercising a disturbing products which are formed in situ upon the floor of the influence, that it is less surprising that criticism should ocean, and here, perhaps, the interest of the work for the sometimes have been provoked, than that results so subgeologist culminates. We can only refer to the numerous stantial, and, on the whole, satisfactory, should in the and interesting problems connected with the origin of the end have been attained. red clay, the mode of formation of the glauconite-casts, The present Report forms the last of the series of the source of the materials and the chemical processes in- splendid monographs in which the results of this famous volved in the formation of the phillipsite and other zeolites, Expedition-one which will be recorded in the history the manganese-nodules, and the phosphatic and other of Science as perhaps the grandest concession to her concretions. The 76 pages of text, and the admirable claims made up to the present time by the British or drawings which illustrate this part of the subject, will any other Government-are fully recorded and discussed. excite the interest of alì students of the subject. They The final volume of the Challenger Reports, which, it is enable the reader to form a clear idea of the forms and stated, will probably be published in the course of the structure of the remarkable manganese nodules, and of present year, will contain lists of the organisms collected the ear-bones, teeth, and other objects which, in a more at every observing station, with other details, in the or less phosphatized condition, are strewn
nature of a summary of results. JOHN W. JUDD. deepest part of the ocean-floors. In an appendix is given a report on the analysis of the manganese-nodules
PARASITIC FUNGI AND MOULDS. by Dr. John Gibson, especial attention being directed to the detection of the rarer elements by spectroscopic and
British Fungi : Phycomycetes and Ustilaginea. By G. other methods. While traces of barium, strontium,
Massee. (London : Reeve and Co., 1891) lithium, molybdenum, zinc, titanium, vanadium, and IT is a somewhat remarkable fact that no one has thallium were found, cæsium, rubidium, and the metals hitherto written a book on the British Phycomycetes, of the cerium and yttrium groups were sought for in vain. the common white moulds so often found growing on The quantitative analyses, as shown by the tabular state- decaying substances or in water, or as parasites of a ments, would appear to have been executed with every most destructive kind in various valuable plants; and the modern refinement, and were carried out, by Prof. Crum opportunity thus afforded to the writer of the present Brown's permission, in the Chemical Laboratory of the volume was a good one, of which, it is but fair to say, he University of Edinburgh. Another appendix contains has taken considerable advantage. The Ustilaginea an account of the analyses which have been made of the of this country had already been treated by Mr. Plowdifferent varieties of deep-sea deposits.
right, but there are sufficient differences between the In conclusion, we may point out that the work is worthy works of the two authors to make Mr. Massee's book of praise, not only for what it includes, but for what it none the less noteworthy on that account. omits. The time has not yet arrived for a full discussion of When we consider the great variety of “white moulds,” the geological bearings of many of the new and interest- | such as Mucor, that infest all kinds of rotting fruits and ing facts brought to light by the Challenger Expedition. Other vegetable débris, of parasites such as the PhytophTheoretical discussions are, therefore, wisely kept, in the thora of the potato disease, and the Peronosporea which monograph before us, within very narrow bounds. It is destroy onions, vines, and other valuable vegetable proevident that much of the work was written before the duce, to say nothing of the Saprolegnia of the salmon publication by Messrs. Jukes-Browne and Harrison of disease, the Pythium which decimates seedlings of all their interesting memoirs on the geology of Barbadoes, kinds, and the Empusa which kills our house-flies in and before the discovery of the Radiolarian-chert of Ayr. autumn, and glues their dead bodies to the window-panes shire and other districts. These discoveries, it is true, are — when we regard these and a host of other extraordinary mentioned in footnotes, but have evidently had but little and important Phycomycetous Fungi, it seenis more and influence in moulding the views of the authors. Few more surprising that no one has compiled an intelligible geologists will be prepared to accept the views of Mr. account of these things in this country ; yet so it is, and Murray, when he endorses the conclusion of M. Cayeux the author of this little book of a couple of hundred of that the white chalk should be classed as a terrigenous pages of carefully, and, on the whole, pleasantly-written deposit. But on this and other points the views of the matter, ought certainly to deserve the thanks of botanical authors are stated with a commendable absence of dog- readers for undertaking the difficult task, and discharging matism, and a manifest desire to lay before readers of it as well as he has done.
In reviewing the work there are two parts to be noticed, to the point. We have not tested the indices in detail, and two points of view from which to criticize them: the but they are very well planned, and appear to be accurate. first fifty pages or so are concerned with a general On the whole, and without being blind to its faults, we popular account of the morphology of Fungi in the wider think this little book should be welcomed as a useful sense, while the remainder is devoted to the setting forth manual on the subject, and should certainly be in the of the British genera and species (so far as they have hands of students of botany who wish to know something been worked up) of the two groups specially dealt with. of British mycology.
The general account must strike a careful reader as not only exhibiting a good deal of knowledge on the part of a writer who is wishful to put it at the disposal of all who
OUR BOOK SHELF. care for it, and in a pleasant style ; but also as showing A Treatise on the Geometry of the Circle, and some what enormous advances have been made in the popular
Extensions to Conic Sections by the Method of Reexposition of these matters within the last few years.
ciprocation. With numerous Examples. By W. J. When we look back to the systematic books on Fungi of
M'Clelland, M.A. (London: Macmillan, 1891.) ten to fifteen years ago, they appear hopelessly dry and This is a full book, written on the lines which previous uninteresting ; whereas here we have a compact, neat us. The author acknowledges his indebtedness to the
works by Irish mathematicians have made familiar to little volume, with a store of interesting information writings of Mulcahy, Salmon, and Townsend. He has thrown in as an introduction to the more serious detailed also freely consulted the similar works by Cremona and work which follows.
Catalan, and in his treatment of the recent geometry has We do not mean to say that this part of the book is in many cases gone to the fountain-head in the memoirs without mistakes or slips, either of fact (e.g. the state
of Brocard, Neuberg, and Tarry. Though in parts proment on p. 49 regarding mutualism between Fungi and ceeding on parallel lines with Casey's “ Sequel," there is
a good deal of other matter not to be found in that work. Phanerogams) or judgment (e.g. the reference The writer's object is to give a concise statement of those “phanerogamic Fungi” on p. 11). Moreover, there are propositions which he considers to be of fundamental evidences of careless proof-reading, as at the foot of importance, and to supply numerous illustrative examples. pp. 41 and 42. But it is far more easy to pick small Many of the exercises are worked out in an elegant holes in a book like this than to do proper justice to manner, and
to the major part of the others useful hints what is good and useful in it; and we prefer to dwell on sections, is devoted to “Maximum and Minimum”;
are given. Chapter i. is introductory ; chapter ii., in four the more important positive points, than to emphasize chapter iii., also in four sections, rapidly touches upon the fewer and more trivial drawbacks.
“Recent Geometry”; chapter iv. discusses the general The more purely systematic part of the work shows theory of the mean centre of a system of points ; and evidence of careful and conscientious industry, suggesting chapter v. treats of collinear points and concurrent lines. constant reference on the part of the author to type-points with respect to a circle, poles and polars (with
Chapters vi., vii., and viii. are concerned with inverse specimens and authorities.
Of course, it is not so inter- respect to a circle), and coaxal circles. In these chapters esting to the general reader, but the diagnoses are so will be found ample food for the student. Chapter ix. clear, and so simply written, that we think any amateur gives an account of the theory of similar figures, and ought to be able to follow them with the object in hand ; here we specially notice the sketch of Neuberg's and as for professional mycologists, they will probably wonder Tarry's researches on three similar figures. Circles of that it could all be put so plainly-at the same time, they chapter x.
similitude and of antisimilitude form the subject of
Here some interesting problems are solved. will suspect something is wrong with the German refer- Inversion (chapter xi.), general theory of anharmonic ence on p. 162, and will probably remark on the chapter section (chapter xii.), involution (chapter xiii.), and double on “ Fossil Fungi.” They may also inquire why Ustila- points (chapter xiv.) close what must unhesitatingly be ginea are taken with Phycomycetes. The author answers
called a varied and ample menu. The work, being conthis question on p. 160: he follows Brefeld in regarding before the reader much that is old ; there is, however,
fessedly to a great extent elementary, of course brings Protomycetes as linking the two groups.
novelty in the treatment and also in the matter. There antiquated method of obtaining sections, on p. 62, had is one feature we have omitted to mention, to which Mr. better have been omitted.
M'Clelland draws attention, and that is the application of The most interesting points to the systematists will be reciprocation to many of the best known theorems by Mr. Massee's almost consistent alterations of Plowright's means of which the corresponding properties of the conic authorities for the species of the Ustilaginea, and his
are ascertained. To go through all the examples would
occupy more time than we can spare, but we have addition of one or two new ones-e.g. / stilago salveii dipped into all parts and brought up good results. In (p. 177), Doussansia comari (p. 198), and Protomyces the text we have noted one slip: p. 60, l. 12 up should purpureo-tingens (p. 164); they will also notice the fusion be 1 - B. No doubt we have omitted to mark other of some species kept apart by Plowright-e.g. on pp. 178
The figures, which are white lines on a black and 186—and the separation of the two species of Tuber block, carry our thoughts back to old Cambridge days, cinia, on pp. 203 and 204.
when we turned over the pages of our Miller's “ Hydro
statics." The geometer will find much to interest him in We note, also, that Massee has altered the name of Mr. M'Clelland's work. Trail's Entyloma matricaric to E. Trailii, possibly on good grounds ; but we think it a mistake to use such
Kalm's Account of his Visit to England on his Way
to America in 1748. Translated by Joseph Lucas. specific names, here and elsewhere, seeing how much
(London: Macmillan and Co., 1892.) Fungi are in need of useful distinctive appellations.
KALM was a well-known Swedish botanist and economist The figures on the six plates are fairly well drawn
of the eighteenth century. In 1747 he became Professor and selected, and the references to them are useful and of Economy at Abo, and in the same year the Swedish
Government and Academy of Sciences commissioned knows?” and that my answer was, “ Probably not." Then Sir him to go to America, the object being that he should
William continued (Question 663): “But, on the other hand, describe the natural productions of that part of the
a teacher may, with judiciousness, &c., teach the best that he
Then said Sir William world, and introduce into Sweden any useful North knows? 'to which I answered, “ Yes.” American plants which might be expected to thrive in
(Question 664), “ If he is examining his own pupils he may bring Northern Europe. Kalm reached England in February
into the examination something of the best and the newest ?” to
which I replied, “Certainly.” 1748, and remained there until August, when he started
It is clear enough that Sir William Thomson's proposition, for America. On his way back, in 1751, he visited this to which I assented, was that, under the London system of country again, staying about a month. An account of external examiners, an examiner cannot put questions involving a portion of his travels he afterwards published in three the best and newest ; yet a teacher may and should teach the volumes. The part relating to America was translated best and newest ; and if, contrary to the principle of the L indon into English in the eighteenth century by J. Reinhold system, the examiner is the teacher, he can introduce with judgForster, but the author's account of England appears
ment into the examination this element of the best and newest. now in English for the first time. The work is full of
Mr. Dyer has not, it seems to me, yet mastered the disinterest, and was well worth translating. Kalm first
tinctive features of the German or professorial University records his impressions of London and suburbs, and
system, and is, therefore, not a trustworthy guide as to its
E. RAY LANK ESTER. then takes us successively to Woodford, Little Gaddes- advantages and disadvantages. den, and Gravesend, each of which is made a centre for a number of observations, chiefly in connection with
Superheated Steam. agriculture. To students of the history of agricultural
A COMMUNICATION froin Lord Rayleigh, under the above methods the work will be invaluable; but it will also give heading, in Nature of February 18 (p. 375), draws attention pleasure to readers with a less serious purpose, for it
to a misunderstanding which has been pointed out by me on contains suggestive references to many aspects of Eng; plaining the thetaphi diagram in public, saying that “only the
every occasion in the last twelve years when I have been exlish lise, and the author always writes accurately and
heat which superheated bad its efficiency increased, according to with good taste. The translator has accomplished his the temperatures at which its respective portions were imparted task with great spirit and intelligence.
to the working substance.” Mr. Willans has also been disseminating correct views regarding this point amongst those who
visit his engine-testing laboratory. The diagram given by me LETTERS TO THE EDITOR.
in my paper on thetaphi, in 1880, makes this very plain. [The Editor does not hold himself responsible for opinions expressed by his correspondents. Neither can he undertake
S to return, or to correspond with the writers of, rejected manuscripts intended for this or any other part of NATURE.
IR No notice is taken of anonymous communications.]
EXHAUST sions of opinion on University organization. I have before now joined my word to his in condemnation of Sir George Young's proposed "Albert” or “Gresham" Charter. Nevertheless, I must beg you to grant me space to point out some inaccuracies in Mr. Dyer's letter in your columns of February 25 (p. 392), the purpose of which seems to be to give reason for
M distrusting, or, at any rate, treating with little confidence, University organizations on the German or prosessorial model.
Mr. Dyer rightly enough appeals to his own early experience as a teacher and student. It is therefore fair to point out that this experience does not include a German University, and that
ABSOLUTE ZERO the conception of it sketched by him, and of a professor's relations to his pupils therein, is entirely erroneous.
Mr. Dyer cannot free his inind of the University of London tradition.
The vertical ordinates here are absolute temperatures, and the He regards the German as well as all Universities as organiza
area is heat or energy. Without superheating, Carnot's law tions for bringing candidates up to a certain pitch of examina.
gives, between temperatures A and Btion-room performance. This is not what a German University
E = attempts. The measure of its success is not what Mr. Dyer
M + N would suggest, but is found in the contributions to science, the
Superheating to temperature S, the same law gives— new knowledge created by the professor and his students, and
Work in the spread of a love for producing such new knowledge.
N + Q + R Mr. Dyer attributes to Lord Sherbrooke a strange saying
H, Heat M + N + P + Q + R' namely, that prosessors who examine their own students are An arithmetical expression for these quantities, practically comparable to tradesmen who sample their own goods." I accurate, is obtained by extending the formula given in Mr. can hardly credit that Lord Sherbrooke ever said anything so Willans's paper on engine trials, at the Institution of Civil unmeaning. We have all heard the professor-examiner com- Engineers pared to “a merchant who brands his own herrings ”—but this
A = steam temperature, not superheated. "sampling of his own goods” is a new charge.
B temperature of exhaust. Lastly, I must point out that Mr. Dyer, by inadvertence,
S superheated temperature. attributes to me a statement, or rather assent to a statement, The temperatures are all absolute, and, to suit engineers, in before the Royal Commission on the proposed new University Fahrenheit measure, and the steam data of Regnault are adopted. for London, which had exactly the opposite significance to that The mean specific heat for the range of superheating is taken which he gives to it. Mr. Dyer says that I admitted to Sir
= 0'5. This will be nearly correct at high temperatures, and William Thomson that “a teacher may, with judiciousness of this is strictly in accordance with my statement that the specific course, and with common-sense in his teaching, teach the best
heat of steam at low temperatures is 0-39 at constant pressure. that he knows” under the present University of London The above expressions become, without superheating, system. I am glad to note that Mr. Dyer has looked at the
A - B 1437 Blue-book. But if he had read more carefully he would have
E: seen that Question 662, by Sir William Thomson, was, “Can an
H examiner under the London system ask the best that he
3A - B