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unbounded labour, and a deep sympathy with the subject. THURSDAY, MARCH 16, 1893.

We are not going to hold it up as a model “ Fauna”; there is evidence, notwithstanding what we have just said,

of too much haste in its composition for that; but it WACPHERSON'S FAUNA OF LAKELAND. certainly belongs to the first class of books of its kind,

while, should it be the author's good fortune to have * Vertebrate Fauna of Lakeland, including Cumberland

another edition demanded, a severe revision might give it and Westmoreland, with Lancashire North of the

a high place in that class. We do not assume ourselves Sands. By the Rev. H. A. Macpherson, M.A., with a

to be purists in style, but it does seem to us that the Preface by R. S. Ferguson, F.S.A. (Edinburgh: D.

English language, as written by men of acknowledged Douglas, 1892.)

literary merit, is wide enough to cover every shade of NTRODUCED to the vocabulary of naturalists by meaning, without the least necessity of bringing in words

Mr. H. Cottrell Watson, more than fifty years ago, or phrases that border upon slang, and certainly without id that in the most prosaic way, the word “Lakes," as using slipshod expressions that, if not altogether inaple name of an English district, still keeps its poetic

propriate, are in many cases vague and therefore unagrance, which is perhaps even intensified by its seemly in a book that may fairly claim to rank among jodern modification into “Lakeland," notwithstanding scientific works. We assure the author in all good will be very technical prefix, as in the title of this book, of that these shortcomings, which might be so easily

A Vertebrate Fauna." One is naturally led to think of remedied, greatly diminish the pleasure we derive from hat school of versifiers whose early efforts excited so nany conflicting feelings when the century was young, Apart from Mr. Ferguson's scholarly Preface, the book but whose later lays have at length brought conviction of opens with more than one hundred pages of Prolegomena, their worthiness to the minds of most. One of their and we are mistaken if the greater part of these will not company, he who furnishes the motto of this journal, has prove to have greater interest for that incomprehensible especially been hailed as the Poet of Nature, and not person the General Reader than all that follow-the paronly does the fame of Wordsworth wax yearly, but there ticulars, given in the bulk of the volume being mostly of are those who greet every line he wrote with adulation. especial and local value. Not that we use this last epiTo such admirers the author of the book before us will thet in any invidious sense, for what should a local seem to have missed his opportunity, in that we fail to Fauna be but local? and Mr. Macpherson has avoided a find in the whole volume any indication of the penulti- | great error (into which the authors of some modern local mate Poet Laureate having ever belonged to the “Verte- Faunas have fallen), by rightly taking it for granted that brate Fauna of Lakeland.” Does this signify that the zoological readers who will use his book do not want naturalists are not poetical or that the great “Poet of to be instructed on points or matters concerning which Nature” was not a naturalist? The question is so they can obtain full information from many other and momentous that we leave it for consideration by our more original sources, and thus he is able to husband his readers, not daring to vouchsase a reply, nor venturing space for particular details, which are given in most cases to suggest to Mr. Macpherson that he has been wrong in with great precision. But first of these Prolegomena aforeresisting the temptation to illustrate his work by quota said—They begin, as every book of this sort ought, with tions, that might be gathered by the handful from the what is practically a history of the subject ; for it is a thousands of verses which flowed from the pen of the biographical notice of former Lakelandish worthies who "bard of Rydal,” or any of his brethren.

have contributed to the Vertebrate Zoology of their We must acknowledge that we took up this volume district, and of these there is a good show; though there with a slight prepossession against it. We did not see is no wonder that the earliest writers on the subject should why Mr. Macpherson, already the joint author of a well possess but little scientific knowledge. It is not every known and well-esteemed little book on the “ Birds of county that can produce a Willughby, a Sir Thomas Cumberland," to say nothing of various contributions to Browne, or still less a John Ray-but probably the earliest Natural History journals, should need a preface for his new of the naturalists celebrated by Mr. Macpherson were work by a gentleman who-whatever may be his legal and the equals of Charleton, Plot, or Leigh-all men worthy antiquarian renown (which we believe to be not small) — 1 to be praised in their own line. Yet setting aside these is entirely unknown as a naturalist, and it seemed to us lesser lights, many of whom are lost to view in the glare as though a kind of sub-episcopal imprimatur, which that radiates from their successors, the two Heyshams would be derogatory to a man of science, had been sought (John, born 1753, died 1834, and Thomas Coulthard, from the Chancellor of the diocese of Carlisle. We have born 1791, died 1857), and the two Goughs (John and been glad to find this suspicion, perhaps ill-natured in its Thomas, whose joint lives cover all but a century and a inception, wholly unfounded as we became acquainted quarter, 1757-1880)-in each case father and son-were with the contents, and we hereby make confession of our men deserving commemoration in any county, and the error, daly cautioning all others, and there may be a good biographical notice of all four, written in excellent taste, many of them to whom the same thought may occur or have will be gladly read by many who are not naturalists at all. occurred, that any such hesitation is unnecessary. The For our own part we cannot help wishing that these Preface, it is true, contains a benediction, but none can biographical details had been longer ; but the papers of say it is a benediction that is undeserved. The book is the elder Heysham are not forthcoming, neither is the a real honest book, and one that no true zoologist can fail manuscript Cumberland Ornithology, which the younger to discover has been wrought at with conscientious care, is supposed to have left at his death. The former, if still existing, would no doubt throw much light on more than treatise on the Variation of colour in A als so : fifty years of Cumbrian Natural History ; but most likely to be said, and this capitulus 7 disp t sa everything of value in the latter was communicated to consult it, while we take leave to observer Bell or Yarrell, with whom its author was in frequent 'many authorities are cited from the Cor p correspondence, and during his later years he led a life 'these times to Dr.Caius of 1570,that lezne of seclusion. The elder Gough was an extraordinary never wrote a book with a title so ta g a as . instance of a naturalist successfully pursuing his rariorum animalium et si sti

d vocation under a grave difficulty, for the like have been taken 'p. Invi, note) at second bad se of which we can only call to mind Huber and of the popular writers, who imagine tk s are u M. Van Wickevoort-Crommelin, since at an early age animals and do not know the techoaca!

* * he became blind from small-pox, and if he was thereby stirpes. Albinescent specimens if not alboos are disabled from advancing investigation according to his known, a great charm for some collector , Oce bent, it did not hinder him from training his son to follow any reasonable being can say-ani is en h oe his footsteps and indoctrinating him with so wide an author chiefly discourses using too a

es attachment to science that be became an intimate friend ism -quite unfamiliar, but apparently setzte ga and correspondent of Sedgwick the geologist and of as the recognised - albinisinthoegh so far as reason Cornelius Nicholson the antiquary, establishing with the little scientific interest attaches to the : 50 ve do 3 latter's aid the Kendal Literary and Scientific Institution quite see the point of his remarks

sc e The pious duty of celebrating his predecessors obsequies tendency in the direction of variation of the Lakes being performed, Mr. Macpherson next turns to other l'iper. He only mentions two examples, 204 was an extinct mammals of Lakeland, and his researches re- they among so many? Serertheless the see igared. specting the Wolf an entire skeleton of which, found in strange-looking enough, and it would bare bees a cave by Mr. John Beecham, is preserved in the factory to be assured that there can be do Distake e museum at Kendal, and the Wild Boar bare been re- deteranination of the species. The socceedz chapter warded by the discovery of documentary evidence not devoted to Hybrid Birds; bat bere agais se without interest, even if it does not add much that is of much of interest in a general war on the E

. value to our information concerning these ancient beasts. and extremely interesting, not to say important, bec We have too some facts in relation to the Red Deer and Mr. Macpherson has been so fort nate as to see sort the Wild Ox, though more is said of them, and some of than one wild hybrid between the tro British soccer it is of importance, in the body of the work 'pp. 50-76). Sparrow Passer domesticus and P. OO 250 con and we do not see why the former at least of them should sidering that these are species in wha: some vol i be called extinct, seeing that though greatly restricted in the “physiological o sense-be seves bemg ostis range it still exists in freedom, wbile the latter, whose alike in the latter and wholly diferent in the barenight German name Mr. Macpherson persistently curtails, the question deserved further attention than s bestowed misspelling it “ Auroch " for Aurochs, was undoubtedly upon it Pp. lx-m . the ancestor of the white breed, of which the last herd in More instructie is what follows on - Bird Forg the district, having been emparked at Thornthwaite near (as the author redundantly terms it or r2:be se sasi Haweswater, was removed in or soon after 1630 to say more instructive it might be. There is best Naworth, and by 1675 had ceased to exist. A chapter .Imviii, of the setting of Razorbills and G emas C devoted to - Tbe Destruction of Wild Animals will the rocks of St Bees, takea, we are free the be instructive reading to many people. It contains **Sandford MS. p. 18," but where this manuscript s to be what will be a revelation to those who can appreciate seen or of what age it may be we are not to

be the facts of how not to do it. Our excellent forefathers language of the passage quoted only shows that SDK and many of their descendants are not much wiser exactly of yesterday. Nor the betting of Alde is not knew very lizele of the way in which wild beasts could be so far as we are aware, known to bave bece at extirpated, and consequently the warfare against them elsewhere in Britain and Mr. Macphersoa sans obe c lasted for centuries. Some few, still accounted enemies is obsolete in Cumberland, probably from there so en of the human race, yet defy their persecutors ; but the birds enough left to make its continence word the te greater number have perished, and in the present depleted, of the “ Hivites, for it may be accepted as a seversaire state of the Mannalian Fauna of the British Islands, it that the taking of birds at their breeding barnts year afe would be inexpedient to point out how the extinction, at , year, unless under such conditioes as S. Kida presos, least in parts, of some two or three species might be ac- l must end in their dimination and may easily be carried complished in perhaps twice as many years. The average i on to their extinction. gamekeeper i fortunately or no: has very little knowledge. For the rest of the Prolegomena there is no see to say of zoology, and the average master even less. On this par- | anything, and we willingly pass over the aseless repor ticular we have no wish to enlighten either, so we shall, sentation R XCV. of the Polish Sran's trades, preserve a silence that all animals friends will admit to we congratulate Mr. Macpherson on being able to get be golden. But we must always remember that by far the 'p. cin the foot of a real Westmorlaad Sea-Eagle, xa most destructive four-footed“ vermit of our day is re- mere “ marauder from over the border-95 oss ligiously and rigorously preserved by a general senti- the examples killed in England art—bat a wot e ment, so much stronger than any law, in a way that would for all that. have caused to wonder those who kenned John Peel * into the details of Lakeland species se skal a and his forefathers. In favour of V: Macpherson's next i tempt to enter. To criticise that portion of the

the critic should have nearly as much local knowledge as That there is such stability is clear from the considerathe author, and we pretend to none. To some though tion that, if one of the bodies rotates more rapidly than not to a great extent the besetting sin of nearly all the other, it is subjected to a more rapid retardation of

Faunists” is evident, and that is the tendency to exalt rotation, and there is accordingly a tendency towards the the importance of the capture of stray individuals, restoration of equality. this especially among birds. The occurrence of The influence of tidal friction on the elements of the these wanderers is undoubtedly worth recording; but orbit of a satellite and on the rotation and obliquity of a that a zoologist should claim consideration for Cumber- planet have been investigated in my several papers, and land because a Saxicola isabellina was shot there, Mr. See here adapts my conclusions to the case of the or for Furness because a Pelagodroma marina was double tidal friction of two stars. The adaptation is washed up on Walney, is an indication that he takes not difficult, for whilst the rate of change in the rotation rather a narrow view of things-though we are bound to of each star remains the same as though the other did admit that Mr. Macpherson at the same time descants on not rotate, the rates of change of the elements of the the merits of the Wheatear as a characteristic Lakeland / orbit are exactly doubled. Mr. See has then redrawn bird ; and, especially as befits one by descent" servile to | the curves which exhibit the gradual transformation of Skyey influences", laments the almost complete absence the system, and, as might have been expected, finds from the Lakeland seas of the Manx Puffin, due no doubt them to have features closely similar to those of my to its extirpation in the neighbouring island, or its Calf, | curves. that gives it an English epithet nowadays inappropriate. The generality of these solutions is limited by the supIndeed there is no fault to find with our author in his | posed smallness of the eccentricity and of the inclinations sympathy for the true denizens of his district, and the of the orbit and of the two equators to the plane of highest praise is due to him for the labour he has exer- | reference. The author, however, then passes to a second cised, of which almost every page bears witness, in telling case, which is more special in that the equators of the their story. To wind up we must add, what perhaps we stars remain coincident with the plane of the orbit, but ought to have said before, that for the purpose of this which is more general in that the eccentricity is not work" Lakeland " consists of the counties of Cumberland | treated as being necessarily small. The object is to obtain and Westmorland, together with that part of Lancashire a numerical solution of the following problem :--Two known as Lancashire Over-Sands, being identical, the Isle equal stars, each of three times the sun's mass, revolve of Man excepted, with the "twelfth Province" of Mr. / in a nearly circular orbit at a distance equal to that of Watson's Cybele Britannica ; but the want of a map of Neptune from the sun, and the rotation of each star is the entire district is a grievous drawback, for which even nearly equal to its orbital motion ; it is required to find the dozen or more excellent etchings, showing as many the greatest mean distance and the greatest eccentricity places of interest, do not wholly make amends.

of orbit to which the system will change under the influence of tidal friction.

Mr. See solves this problem by methods analogous to THE EVOLUTION OF DOUBLE STARS.

those which I have employed, and finds that the mean

distance will increase from 30 (Neptune's distance) to 50, Die Entwickelung der Doppelstern-Systeme. Von T. J. and that the eccentricity will increase from an assumed

J. See. 60 pp. (Berlin : R. Friedländer und Sohn, / initial value of one-tenth to a maximum of about three1893.)

fifths, which is attained a little earlier than the maximum THE essay which we review is a dissertation for the of mean distance.

doctorate of philosophy of Berlin, and the author, It may be remarked that these results can only be very Mr. See, is an American, although he writes in German. rough approximations to the truth, because the calculation

The component stars in double systems appear to be is conducted on the supposition that the moment of inertia usually of comparable magnitudes, and are found to of each star is the same as that of a homogeneous move in highly eccentric orbits. This case the author sphere of the same mass and radius, whereas it is obvious holds to be the normal one, whilst the solar system, with that the stars would really be highly condensed spheroids its one preponderant mass, and its nearly circular orbits, l of great oblateness. would be exceptional.

It is to be regretted that the calculation has not been He attributes the observed high eccentricity of orbit | repeated with variations of the assumed initial conditions. to the influence of tidal friction, and accordingly the It is easy to see that a change in the assumed degree of greater part of the paper is devoted to the consideration concentration of the stars would give very different reof the results which will ensue from the supposition that sults. Supposing, for example, the stars had had only each of two bodies raises in the other tidal disturbances, half the diameter assumed, the rotational moment of which are subject to frictional resistance.

momentum would have had a quarter of its value in Mr. If the rotations of the two bodies differ in speed, the See's example. Now the enlargement of orbit is due to problem is an insoluble one, without some postulate as to the transference of rotational to orbital moment of the law of the frictional resistance. The author is, how- | momentum, and thus the transferable moment of momenever, of opinion that sufficient insight may be gained tum would only have amounted to one quarter of its former from the solution in the case where two equal bodies | value. But the orbital moment of momentum varies rotate with equal speed. "This opinion seems justifiable, as the square root of the mean distance, and hence the but it might have been well if the dynamical stability of enlargement of the orbit could not have been so much as equality of rotations had been explicitly pointed out. I one-sixteenth of its former value. We may feel sure that the increase in the eccentricity of orbit would also have the ring of Saturn as being as exceptional in its history as been largely reduced.

it now is in appearance. Where he maintains that Saturn's Notwithstanding this criticism, it appears to me that ring will never coalesce into a satellite, he might with Mr. See fairly establishes the proposition that a high advantage have referred to the remarkable investigations eccentricity is explicable by means of tidal friction. of M. Roche, who showed that a satellite would be torn

Turning, then, to the question of the relative masses o to pieces by tidal action if it revolved at a distance of the components of double star systems, Mr. See remarks less than 2.44 times the planet's radius. We may here with justice that the comparable brightness of the com- note the interesting fact that whilst Saturn's ring almost ponents renders it highly probable that the masses are touches “Roche's limit" on the inside, the Martian sate! also comparable, and he sees in certain results of M. lite, Phobus, and the fifth satellite of Jupiter* almost touch Poincaré and of my own an evolutionary explanation of it on the outside.3 this fact.

In order to prove his thesis as to the highness of the Jacobi first showed than an ellipsoid of homogeneous eccentricity and the comparability of masses, Mr. See fluid, with its three axes bearing to one another proper gives a careful table of the observed elements of the orbits proportions, is a figure of equilibrium when it rotates and of the relative brightnesses of seventy-three pairs of about its smallest axis with a proper angular velocity. double stars. The values of the elements are of course M. Poincaré next showed that if the length of the Jacobian open to much uncertainty, but the mean eccentricity, ellipsoid exceeds the breadth in a certain ratio, the equili- which is found to be .45, must lie near the truth. In the brium becomes unstable, but that there is a stable few cases in which the masses have been determined, figure which may be described as a Jacobian ellipsoid they are found to be comparable, and the comparabilitý with a furrow nearly round the middle, so that it resembles of the brightnesses confirms the generality of this lax an hour-glass with unequal bulbs. If we trace the further Thus the facts of observation agree with our author's development of the hour-glass we find its neck gradually ideas. thinning, and finally rupturing the figure of equilibrium, Mr. See must be congratulated on having written an henceforth consists of two detached masses.

essay of great cosmogonical interest, and although his My own attack on this problem was from the opposite theory may never be susceptible of exact proof, yet there point of view, for I endeavoured to trace the coalescence is sufficient probability of his correctness to inspire us of a pair of detached masses so as to form an hour-glass with fresh interest in the observations of double stars. or dumb-bell.

G. H. DARWIN. Mr. See reproduces the figures illustrative of both these investigations, and remarks that they both show that when there is a gradual detachment from a rotating figure of MAGNETIC INDUCTION IN IRON AND equilibrium, the detached portion will not norma lly be

OTHER METALS. a ring, but that there will ensue two quasi-spheroidal Magnetic Induction in Iron and other Metals. By J. A masses of matter of comparable magnitude. He also remarks that if the fluid be heterogeneous, the ratio of the

Ewing, F.R.S. (London: Electrician Office.) masses will be much smaller than when it is homo. In this admirable book Prof. Ewing has brouga: geneous.

together matter which was before to be found only In the discussion of these figures of equilibrium the

in the journals of learned societies, and he has also wording of the essay appears a little careless, for it might given a full account of his own researches in magnetism. naturally be supposed to mean that increase of angular The book is written in a lucid style, and is supplied with velocity is a necessary concomitant of the rupture of the numerous references to original papers. neck of the hour-glass. Now it is a somewhat paradoxical

In Chapter I. Prof. Ewing explains clearly the mearfact that, with constant density, the longer elongated ing of such terms as “intensity of magnetisation" and figures of equilibrium rotate more slowly than the shorter the like, which many students have difficulty in undezones, and it might therefore seem that the rupture of the standing. As stated in the preface, he has “endeavoured neck should go with retardation of angular velocity. But to familiarise the student with the notion of intensity of it is the value of the square of the angular velocity divided magnetisation (I) as well as with the notion of magnesio by the density which determines the length of the induction (B).” When endless magnetic circuits are diselongated figures, and thus increase of density tells in cussed, it is convenient to talk of “permeability" and " iathe same way as retardation of angular velocity. In the duction”; on the other hand, magnetic poles" 200 history of a nebula the only condition for rupture which

“magnetisation" are just as important when permanez can be specified is that of contraction.

magnets are dealt with. The magnetisation of ellipsoids The probability of this view of the genesis of double

and the influence of the shape and dimensions of stars is strikingly illustrated by a number of drawings by magnetised bodies upon magnetic quality are ful; Sir John Herschel of various nebulæ: The great similarity

treated. between Herschel's nebulæ and the theoretical hour-glass 1 "Acad. des Sciences de Montpelier," vol. i. (1847-50), p. 243. Seza is obvious. It may be hoped that in the book which Mr.

Darwin, Harper's Magazine, June, 1889.

2 The values given by Barnard (NATURE, P. 377) make the disco See promises he will also illustrate this point by photo- 112,000 miles, and Roche's limit 107,ovo miles. graphs.

3 It is proper to warn the reader that Roche's limit depends to some er.

on the density of the planet. For the sun it will be about one-tenth of Annulation is usually accepted as the mode of separa

earth's distance from the sun. Thus a body of planetary size cannot

in a highly eccentric orbit, so that its perihelion distance is one-tents, w tion in the nebular hypothesis, but, as already stated, this out being broken up into meteorites ; and conversely a flight of natuurbs is held by Mr. See to be exceptional. He thus regards planet.

with less than the same perihilion distance can never coalesce s

a

A T

a 2T

Chapters II. and III. are devoted to measurements of In the latter part of the chapter hysteresis, in the magnetic quality by the magnetometer and ballistic relation of magnetic susceptibility to temperature, methods. With respect to the former very full informa- is dealt with; and mention is made of the wide ţion is given as to the construction of the apparatus and range of temperature through which the alloys of its use.

iron and nickel may exist in either the magnetic or nonThe earth's coil as means for calibrating the magnetic state. Ballistic Galvanometer is fully explained, as also Reference is made to the researches on recalescence of that of a solenoid and current. Mention is not made Osmond, who has since shown the marked influence of the of a convenient method of calibration in which initial temperature, and the rate of cooling on recalthe quantity of electricity passed is given directly escence in the case of chromium steel. Dr. Bottomley by Q = ; where A is the deflection corrected for

has shown that the alloys of chromium and steel in the

unannealed state have exceptionally high magnetic decrement; a is the steady deflection due to unit current, qualities, which are confirmed by experiments of Dr. and = is the periodic time of the ballistic needle. Here Hopkinson. a and 7 are quantities very readily obtained.

In Chapter X. the magnetic circuit is discussed, and The chapter concludes with a full description of Dr. the way in which it is applied to the design of dynamo Hopkinson's “ Bar and Yoke" method.

electric machines and transformers. Reference is made Chapter IV. contains valuable information with regard to the important work of Drs. J. and E. Hopkinson and to curves of induction and hysteresis in the case of Kapp upon this subject — more especially in conwrought iron, steel, and cast iron, which will be of use nection with dynamo electric machinery. In pursuing to the electrical engineer in the design of dynamo electric the analogy of the magnetic circuit to the ordinary machinery. The effects of annealing and stretching iron conduction equation, Prof. Ewing lays stress upon are brought forward and well illustrated.

the fact that the permeability (n) is a function of the The next chapter, on magnetic hysteresis, is perhaps induction (B), and this is a point which cannot be too he most important in the book. It commences by giving strongly urged. Much that is in this chapter has great a clear definition of hysteresis, the effects of which are practical importance-the treatment of the subject being imply illustrated by curves, and stress is laid upon the considered from a graphical, as well as analytical, point of definition of permeability as being the ratio of B to view. The chapter ends with an account of the influence H with certain limitations.

upon magnetisın by cuttings and the compression of The dissipation of energy through magnetic hysteresis joints in magnetic circuits. -which plays such an important part in the design of The last chapter gives a complete account of the ores for transformers, and the armatures of dynamos-is different theories of magnetism. Weber's theory is disully treated.

cussed with modifications by Maxwell and Wiedemann, The remarks on magnetic viscosity towards the end to which are added Prof. Ewing's own views of the of the chapter are worthy of very careful consideration. subject. He goes on to show that the reduction of The author points out that in the case of quick cycles, hysteresis by vibration is explained by the molecular ( HdI may be widely different from what is found to be the theory of magnetism,-and further supposes that time

lag in magnetism can be accounted for by it. The book ase by static methods, and further remarks that experi- ends with account of Ampère's hypothesis of nental evidence is wanting under this head.

magnetic molecules.

E. WILSON. Chapter VI. treats of magnetism in weak fields. The uthor refers to experiments by Lord Rayleigh and imself, in which the time effect upon magnetism is

OUR BOOK SHELF. learly shown--the creeping up of the magnetism going Forschungsberichte aus der Biologischen Station su n for a considerable time.

Plön. Theil I. Faunistische und biologische BeobachMagnetism in strong fields is discussed in Chapter

tungen am Gr. Plöner See. Von Dr. Otto Zacharias, II. The “ Isthmus Method" introduced by the author

Direktor der Biologischen Station. (Berlin: R. Fried

länder und Sohn, 1893.) nd Mr. W. Low in 1887 is capable of producing magetic fields of enormous strength. In giving his

The first report of investigations from the biological

station of Plön, in Holstein, has just been issued. It onclusions from experiments by the isthmus method

is a journal of 52 pages with one plate, bearing on the je author states, “there is apparently no limit to the front of the cover a neat representation of the turreted alue to which the induction may be raised. But, when three-storey building reflected in the quiet waters of the le measure magnetisation by the intensity of magnetism

inland lake, and on the back a list of the regulations we are confronted with a definite limit--a true satura

observed in the management of the station. on value, which is reached or closely approached by already made his views known with regard to the im.

In his introductory remarks the Director, who has he application of a comparatively moderate magnetic portance of freshwater laboratories in the pages of several orce."

German scientific periodicals, gives a brief sketch of the A full account of Dr. Hopkinson's researches on the advance already made in this direction in Italy, France, ffect of temperature on magnetism is given in Chapter

and America. III., and reference is made to the identification of

The first paper gives a list of the fauna at present

known to inhabit the lake. This occupies seven pages; ecalescence with recovery of the magnetic state.

and fourteen names, being printed in italics, signify that 1 For recent experiments upon Magnetic Viscosity see a paper by J.

they are new to science. The new species and genera Topkinson, F, R.S., and B. Hopkinson in Electrician, September 9, 1892. are treated in detail in the second paper. The greatest

an

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