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Vertebrate Fauna of Lakeland, including Cumberland nd Westmoreland, with Lancashire North of the Sands. By the Rev. H. A. Macpherson, M.A., with a Preface by R. S. Ferguson, F.S.A. (Edinburgh: D. Douglas, 1892.)

INTRODUCED to the vocabulary of naturalists by Mr. H. Cottrell Watson, more than fifty years ago, d that in the most prosaic way, the word "Lakes," as e name of an English district, still keeps its poetic grance, which is perhaps even intensified by its odern modification into " Lakeland," notwithstanding e very technical prefix, as in the title of this book, of A Vertebrate Fauna." One is naturally led to think of at school of versifiers whose early efforts excited so any conflicting feelings when the century was young, ut whose later lays have at length brought conviction of eir worthiness to the minds of most. One of their ompany, he who furnishes the motto of this journal, has specially been hailed as the Poet of Nature, and not nly does the fame of Wordsworth wax yearly, but there re those who greet every line he wrote with adulation. o such admirers the author of the book before us will eem to have missed his opportunity, in that we fail to ind in the whole volume any indication of the penultinate Poet Laureate having ever belonged to the "Vertebrate Fauna of Lakeland." Does this signify that maturalists are not poetical or that the great "Poet of Nature" was not a naturalist? The question is so momentous that we leave it for consideration by our readers, not daring to vouchsafe a reply, nor venturing to suggest to Mr. Macpherson that he has been wrong in resisting the temptation to illustrate his work by quotations, that might be gathered by the handful from the thousands of verses which flowed from the pen of the "bard of Rydal," or any of his brethren.

We must acknowledge that we took up this volume with a slight prepossession against it. We did not see why Mr. Macpherson, already the joint author of a wellknown and well-esteemed little book on the "Birds of Cumberland," to say nothing of various contributions to Natural History journals, should need a preface for his new work by a gentleman who-whatever may be his legal and antiquarian renown (which we believe to be not small) is entirely unknown as a naturalist, and it seemed to us as though a kind of sub-episcopal imprimatur, which would be derogatory to a man of science, had been sought from the Chancellor of the diocese of Carlisle. We have been glad to find this suspicion, perhaps ill-natured in its inception, wholly unfounded as we became acquainted with the contents, and we hereby make confession of our error, duly cautioning all others, and there may be a good many of them to whom the same thought may occur or have occurred, that any such hesitation is unnecessary. The Preface, it is true, contains a benediction, but none can say it is a benediction that is undeserved. The book is a real honest book, and one that no true zoologist can fail to discover has been wrought at with conscientious care,

unbounded labour, and a deep sympathy with the subject. 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 certainly belongs to the first class of books of its kind, while, should it be the author's good fortune to have another edition demanded, a severe revision might give it a high place in that class. We do not assume ourselves to be purists in style, but it does seem to us that the English language, as written by men of acknowledged literary merit, is wide enough to cover every shade of meaning, without the least necessity of bringing in words or phrases that border upon slang, and certainly without using slipshod expressions that, if not altogether inappropriate, are in many cases vague and therefore unseemly in a book that may fairly claim to rank among scientific works. We assure the author in all good will that these shortcomings, which might be so easily remedied, greatly diminish the pleasure we derive from reading his volume.

Apart from Mr. Ferguson's scholarly Preface, the book opens with more than one hundred pages of Prolegomena, and we are mistaken if the greater part of these will not prove to have greater interest for that incomprehensible person the General Reader than all that follow-the particulars given in the bulk of the volume being mostly of especial and local value. Not that we use this last epithet in any invidious sense, for what should a local Fauna be but local? and Mr. Macpherson has avoided a great error (into which the authors of some modern local Faunas have fallen), by rightly taking it for granted that the zoological readers who will use his book do not want to be instructed on points or matters concerning which they can obtain full information from many other and more original sources, and thus he is able to husband his space for particular details, which are given in most cases with great precision. But first of these Prolegomena aforesaid-They begin, as every book of this sort ought, with what is practically a history of the subject; for it is a biographical notice of former Lakelandish worthies who have contributed to the Vertebrate Zoology of their district, and of these there is a good show; though there is no wonder that the earliest writers on the subject should possess but little scientific knowledge. It is not every county that can produce a Willughby, a Sir Thomas Browne, or still less a John Ray-but probably the earliest of the naturalists celebrated by Mr. Macpherson were the equals of Charleton, Plot, or Leigh-all men worthy to be praised in their own line. Yet setting aside these lesser lights, many of whom are lost to view in the glare that radiates from their successors, the two Heyshams (John, born 1753, died 1834, and Thomas Coulthard, born 1791, died 1857), and the two Goughs (John and Thomas, whose joint lives cover all but a century and a quarter, 1757-1880)-in each case father and son—were men deserving commemoration in any county, and the biographical notice of all four, written in excellent taste, will be gladly read by many who are not naturalists at all. For our own part we cannot help wishing that these biographical details had been longer; but the papers of the elder Heysham are not forthcoming, neither is the manuscript Cumberland Ornithology, which the younger is supposed to have left at his death. The former, if still

existing, would no doubt throw much light on more than
fifty years of Cumbrian Natural History; but most likely
everything of value in the latter was communicated to
Bell or Yarrell, with whom its author was in frequent
correspondence, and during his later years he led a life
of seclusion. The elder Gough was an extraordinary
instance of a naturalist successfully pursuing his
vocation under a grave difficulty, for the like
of which we can only call to mind Huber and
M. Van Wickevoort-Crommelin, since at an early age
he became blind from small-pox. and if he was thereby
disabled from advancing investigation according to his
bent, it did not hinder him from training his son to follow
his footsteps and indoctrinating him with so wide an
attachment to science that he became an intimate friend
and correspondent of Sedgwick the geologist and of
Cornelius Nicholson the antiquary, establishing with the
latter's aid the Kendal Literary and Scientific Institution.
The pious duty of celebrating his predecessors obsequies
being performed. Mr. Macpherson next turns to other
extinct mammals of Lakeland, and his researches re-
specting the Wolf an entire skeleton of which, found in
a cave by Mr. John Beecham. is preserved in the
museum at Kendal and the Wild Boar have been re-
warded by the discovery of documentary evidence not
without interest, even if it does not add much that is of
value to our information concerning these ancient beasts.
We have too some facts in relation to the Red Deer and
the Wild Ox, though more is said of them, and some of
it is of importance, in the body of the work pp. 50-76),
and we do not see why the former at least of them should
be called extinct, seeing that though greatly restricted in
range it still exists in freedom, while the latter, whose
right German name Mr. Macpherson persistently curtails,
misspelling it "Auroch" for Aurochs, was undoubtedly
the ancestor of the white breed, of which the last herd in
the district, having been emparked at Thornthwaite near
Haweswater, was removed in or soon after 1630 to
Naworth, and by 1575 had ceased to exist. A chapter
devoted to The Destruction of Wild Animals will
be instructive reading to many people. It contains
what will be a revelation to those who can appreciate
the facts of "how not to do it." Our excellent forefathers
and many of their descendants are not much wiser
knew very little of the way in which wild beasts could be
extirpated, and consequently the warfare against them
lasted for centuries. Some few, still accounted enemies
of the human race, yet defy their persecutors; but the
greater number have perished, and in the present depleted
state of the Mammalian Fauna of the British Islands, it
would be inexpedient to point out how the extinction, at
least in parts, of some two or three species might be ac- I
complished in perhaps twice as many years. The average
gamekeeper fortunately or not has very little knowledge;
of zoology, and the average master even less. On this par-
ticular we have no wish to enlighten either, so we shall
preserve a silence that all animals' friends will admit to
be golden. But we must always remember that by far the
most destructive four-footed "vermin of our day is re-
ligiously and rigorously preserved by a general senti-
ment, so much stronger than any law. in a way that would
have caused to wonder those who "kenned John Peel " Into the detalls of Lakeland species we sh
and his forefathers. In favour of Mr. Macpherson's next, tempt to enter. To crise that portion of the

treatise on the Variation of colour Animas
to be said, and this capitulum will disappe
consult it, while we take leave to observe
many authorities are cited from the Car..
these times to Dr. Caius of 15-0, that learned
never wrote a book with a title so tauring
rariorum animalium et aciun dra
have been taken p. lxxvi, note, at second hand f
of the popular writers, who imagine that turus

animals and do not know the technica
stirpes. Albinescent specimens if not albinos are rave
known, a great charm for some colectors-w
any reasonable being can say-and it is of them that
author chiefly discourses using too a word-
ism-quite unfamiliar, but apparently mean no
as the recognised albinism though so far as w
little scientific interest attaches to them, but w
quite see the point of his remarks pr
tendency in the direction of variation of the LacE
Viper. He only mentions two examples, and what
they among so many? Nevertheless the ne gred
strange-looking enough, and it would have been sati
factory to be assured that there can be to stake
determination of the species. The succeed ng.
devoted to Hybrid Birds; but here agam
much of interest in a general way on that Inte
and extremely interesting, not to say important, s.
Mr. Macpherson has been so fortunate as to see
than one wild hybrid between the two British spec
Sparrow Passer domesticus and P. mrez
sidering that these are species in what some

physiological sense-the sexes being outwards
alike in the latter and wholly different in the f
the question deserved further attention than is best
upon it pp. lxxx-x.

There is cent

More instructive is what follows on Bird F (as the author redundantly terms it or rather we say more instructive it might be. lxxxviii of the netting of Razorbills and Galeniu the rocks of St. Bees', taken, we are tox "Sandford MS. p. 18," but where this manuscripts to xe seen or of what age it may be we are not tat language of the passage quoted only shows that it is no exactly of yesterday. Now the netting of Albar is so so far as we are aware, known to have been pre elsewhere in Britain, and Mr. Macpherson says the cur is obsolete in Cumberland, probably from there not birds enough left to make its continuance worth the of the Hivites," for it may be accepted as a om versa, rule that the taking of birds at their breeding batts year afte year, unless under such condtions as St. K. da presents must end in their diminution and may easy be cared on to their extinction.

For the rest of the Frolegomena there is no need to av anything, and we willingly pass over the useless repre sentation p xcv of the Polish Swan's traches, s we congratulate Mr. Macpherson on being able to tgr p. c the foot of a real Westmorland Sea-Ezze mere "marauder from over the border”—is the examples killed in England are-but a mouria re. for all that.

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the critic should have nearly as much local knowledge as the author, and we pretend to none. To some though not to a great extent the besetting sin of nearly all << Faunists" is evident, and that is the tendency to exalt the importance of the capture of stray individuals, this especially among birds. The Occurrence these wanderers is undoubtedly worth recording; but that a zoologist should claim consideration for Cumberland because a Saxicola isabellina was shot there, or for Furness because a Pelagodroma marina was washed up on Walney, is an indication that he takes rather a narrow view of things-though we are bound to admit that Mr. Macpherson at the same time descants on the merits of the Wheatear as a characteristic Lakeland bird; and, especially as befits one by descent "servile to Skyey influences", laments the almost complete absence from the Lakeland seas of the Manx Puffin, due no doubt to its extirpation in the neighbouring island, or its Calf, that gives it an English epithet nowadays inappropriate. Indeed there is no fault to find with our author in his sympathy for the true denizens of his district, and the highest praise is due to him for the labour he has exercised, of which almost every page bears witness, in telling their story. To wind up we must add, what perhaps we ought to have said before, that for the purpose of this work" Lakeland " consists of the counties of Cumberland and Westmorland, together with that part of Lancashire known as Lancashire Over-Sands, being identical, the Isle of Man excepted, with the "twelfth Province" of Mr. Watson's Cybele Britannica; but the want of a map of the entire district is a grievous drawback, for which even the dozen or more excellent etchings, showing as many places of interest, do not wholly make amends.

THE EVOLUTION OF DOUBLE STARS. Die Entwickelung der Doppelstern-Systeme. Von T. J. J. See. 60 pp. (Berlin: R. Friedländer und Sohn, 1893.)


HE essay which we review is a dissertation for the doctorate of philosophy of Berlin, and the author, Mr. See, is an American, although he writes in German. The component stars in double systems appear to be usually of comparable magnitudes, and are found to move in highly eccentric orbits. This case the author holds to be the normal one, whilst the solar system, with its one preponderant mass, and its nearly circular orbits, would be exceptional.

He attributes the observed high eccentricity of orbit to the influence of tidal friction, and accordingly the greater part of the paper is devoted to the consideration of the results which will ensue from the supposition that each of two bodies raises in the other tidal disturbances, which are subject to frictional resistance.

If the rotations of the two bodies differ in speed, the problem is an insoluble one, without some postulate as to the law of the frictional resistance. The author is, however, of opinion that sufficient insight may be gained from the solution in the case where two equal bodies rotate with equal speed. This opinion seems justifiable, but it might have been well if the dynamical stability of equality of rotations had been explicitly pointed out.

That there is such stability is clear from the consideration that, if one of the bodies rotates more rapidly than the other, it is subjected to a more rapid retardation of rotation, and there is accordingly a tendency towards the restoration of equality.

The influence of tidal friction on the elements of the orbit of a satellite and on the rotation and obliquity of a planet have been investigated in my several papers, and Mr. See here adapts my conclusions to the case of the double tidal friction of two stars. The adaptation is not difficult, for whilst the rate of change in the rotation of each star remains the same as though the other did not rotate, the rates of change of the elements of the orbit are exactly doubled. Mr. See has then redrawn the curves which exhibit the gradual transformation of the system, and, as might have been expected, finds them to have features closely similar to those of my


The generality of these solutions is limited by the supposed smallness of the eccentricity and of the inclinations of the orbit and of the two equators to the plane of reference. The author, however, then passes to a second case, which is more special in that the equators of the stars remain coincident with the plane of the orbit, but which is more general in that the eccentricity is not treated as being necessarily small. The object is to obtain a numerical solution of the following problem :-Two equal stars, each of three times the sun's mass, revolve in a nearly circular orbit at a distance equal to that of Neptune from the sun, and the rotation of each star is nearly equal to its orbital motion; it is required to find the greatest mean distance and the greatest eccentricity of orbit to which the system will change under the influence of tidal friction.

Mr. See solves this problem by methods analogous to those which I have employed, and finds that the mean distance will increase from 30 (Neptune's distance) to 50, and that the eccentricity will increase from an assumed initial value of one-tenth to a maximum of about threefifths, which is attained a little earlier than the maximum of mean distance.

It may be remarked that these results can only be very rough approximations to the truth, because the calculation is conducted on the supposition that the moment of inertia of each star is the same as that of a homogeneous sphere of the same mass and radius, whereas it is obvious that the stars would really be highly condensed spheroids of great oblateness.

It is to be regretted that the calculation has not been repeated with variations of the assumed initial conditions. It is easy to see that a change in the assumed degree of concentration of the stars would give very different results. Supposing, for example, the stars had had only half the diameter assumed, the rotational moment of momentum would have had a quarter of its value in Mr. See's example. Now the enlargement of orbit is due to the transference of rotational to orbital moment of momentum, and thus the transferable moment of momentum would only have amounted to one quarter of its former value. But the orbital moment of momentum varies as the square root of the mean distance, and hence the enlargement of the orbit could not have been so much as 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.

Notwithstanding this criticism, it appears to me that Mr. See fairly establishes the proposition that a high eccentricity is explicable by means of tidal friction.

Turning, then, to the question of the relative masses of the components of double star systems, Mr. See remarks with justice that the comparable brightness of the components renders it highly probable that the masses are also comparable, and he sees in certain results of M. Poincaré and of my own an evolutionary explanation of this fact.

Jacobi first showed than an ellipsoid of homogeneous fluid, with its three axes bearing to one another proper proportions, is a figure of equilibrium when it rotates about its smallest axis with a proper angular velocity. M. Poincaré next showed that if the length of the Jacobian ellipsoid exceeds the breadth in a certain ratio, the equilibrium becomes unstable, but that there is a stable figure which may be described as a Jacobian ellipsoid with a furrow nearly round the middle, so that it resembles an hour-glass with unequal bulbs. If we trace the further development of the hour-glass we find its neck gradually thinning, and finally rupturing the figure of equilibrium, henceforth consists of two detached masses.

My own attack on this problem was from the opposite point of view, for I endeavoured to trace the coalescence of a pair of detached masses so as to form an hour-glass or dumb-bell.

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 equilibrium, the detached portion will not normally be a ring, but that there will ensue two quasi-spheroidal masses of matter of comparable magnitude. He also remarks that if the fluid be heterogeneous, the ratio of the

it now is in appearance. Where he maintains that Saturn's ring will never coalesce into a satellite, he might with advantage have referred to the remarkable investigations of M. Roche,1 who showed that a satellite would be torn to pieces by tidal action if it revolved at a distance of less than 2:44 times the planet's radius. We may here note the interesting fact that whilst Saturn's ring almost touches "Roche's limit" on the inside, the Martian sate!lite, Phobus, and the fifth satellite of Jupiter almost touch it on the outside.3

In order to prove his thesis as to the highness of the eccentricity and the comparability of masses, Mr. See gives a careful table of the observed elements of the orbits and of the relative brightnesses of seventy-three pairs of double stars. The values of the elements are of course open to much uncertainty, but the mean eccentricity, which is found to be '45, must lie near the truth. In the few cases in which the masses have been determined, they are found to be comparable, and the comparability of the brightnesses confirms the generality of this law Thus the facts of observation agree with our author's ideas.

Mr. See must be congratulated on having written an essay of great cosmogonical interest, and although his theory may never be susceptible of exact proof, yet there is sufficient probability of his correctness to inspire us with fresh interest in the observations of double stars. G. H. DARWIN.


Magnetic Induction in Iron and other Metals. By J. A
Ewing, F.R.S. (London: Electrician Office.)

masses will be much smaller than when it is homo- IN


In the discussion of these figures of equilibrium the wording of the essay appears a little careless, for it might naturally be supposed to mean that increase of angular velocity is a necessary concomitant of the rupture of the neck of the hour-glass. Now it is a somewhat paradoxical fact that, with constant density, the longer elongated figures of equilibrium rotate more slowly than the shorter ones, and it might therefore seem that the rupture of the neck should go with retardation of angular velocity. But it is the value of the square of the angular velocity divided by the density which determines the length of the elongated figures, and thus increase of density tells in the same way as retardation of angular velocity. In the history of a nebula the only condition for rupture which can be specified is that of contraction.

The probability of this view of the genesis of double stars is strikingly illustrated by a number of drawings by Sir John Herschel of various nebulæ. The great similarity between Herschel's nebulæ and the theoretical hour-glass is obvious. It may be hoped that in the book which Mr. See promises he will also illustrate this point by photographs.

Annulation is usually accepted as the mode of separation in the nebular hypothesis, but, as already stated, this is held by Mr. See to be exceptional. He thus regards

N this admirable book Prof. Ewing has brought together matter which was before to be found only in the journals of learned societies, and he has also given a full account of his own researches in magnetism. The book is written in a lucid style, and is supplied with numerous references to original papers.

In Chapter I. Prof. Ewing explains clearly the mearing of such terms as "intensity of magnetisation" and the like, which many students have difficulty in understanding. As stated in the preface, he has “endeavoured to familiarise the student with the notion of intensity of magnetisation (I) as well as with the notion of magnetic induction (B)." When endless magnetic circuits are discussed, it is convenient to talk of "permeability” and “induction"; on the other hand, "magnetic poles" 25 'magnetisation" are just as important when permanent magnets are dealt with. The magnetisation of ellipsoids and the influence of the shape and dimensions of magnetised bodies upon magnetic quality are ful


1 "Acad. des Sciences de Montpelier," vol. i. (1847-50), p. 243. See 2 Darwin, Harper's Magazine, June, 1889.

2 The values given by Barnard (NATURE, p. 377) make the disa" 112,000 miles, and Roche's limit 107,000 miles.

3 It is proper to warn the reader that Roche's limit depends to some exon the density of the planet. For the sun it will be about one-tenth of 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-tenth, out being broken up into meteorites; and conversely a flight of mete with less than the same perihilion distance can never coalesce planet.

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