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THURSDAY, DECEMBER 29, 1892.

GORE'S "VISIBLE UNIVERSE."

Visible Universe. By J. Ellard Gore, F.R.A.S. ondon: Crosby Lockwood and Son, 1893)

HE object of this book is "not to propound any new
hypothesis, but simply to explain and discuss
ries which have been supported by well-known
nomers and other men of science" as to the "evolu-
of the Solar System," and to give a popular account
e "construction of the Universe as we see it, and its
able development from pre-existent matter."

r. Gore has already acquired considerable success as
pular writer on astronomical subjects, and the scheme
e present volume is, as we might expect, a very good
The first three chapters are devoted to a popular
unt of the hypotheses of Kant and Laplace, the
cipal objections that have been urged against them,
the modifications and additions suggested by recent
arch. In subsequent chapters such subjects as the fuel
e sun, the luminiferous ether, the constitution of matter,
tial chemistry, and the meteoritic hypothesis are
with. Mr. Gore then reaches the purely descriptive
on of his subject, and gives excellent chapters on the
y Way, and on "the latest results respecting the dis-
tion of stars and nebula and their relative motions."
ous theories of the construction of the Universe are
discussed, and in a final chapter the idea of infinite
e and a finite universe is developed.
though the general scheme of the book is excellent,
xecution falls in many places far short of its promise
our expectations. When Mr. Gore confines himself
e historical and descriptive his work is, on the whole,
done, but in discussing theories he has in several
5 obviously ventured out of his depth, and has con-
ently spoiled what would otherwise have been a
able addition to popular astronomical literature.
or his chapters on the Nebular Hypothesis and Faye's
ry of the formation of the solar system Mr. Gore has
ly availed himself of M. Wolf's "Les Hypothèses
ogoniques." He has also introduced extensive
itions from "the late Mr. Jacob Ennis," but in con-
ng Ennis as an authority, Mr. Gore is probably
. Mr. Ennis was, on his own admission, not a
ematician, and certainly did not by "his own dis-
ies," place the nebular hypothesis on a firm mathe-
al basis. He proved Mars could not have satellites;
he heat of the sun was entirely due to chemical
ination; that Sirius has twelve planetary attend ints;
nade several other equally important discoveries.
mathematical demonstration of the truth of the
ar hypothesis is about as sound as the well-known
that the earth's surface is flat. Mr. Gore would
Jone well to have omitted the quotations from Ennis,
› have filled the space with a fuller account of the
mathematical investigations of the nebular
hesis, especially those of Prof. G. H. Darwin.

ing freely from Young and Sir William Thomson,
ore is fairly safe in his chapter on the fuel of the
but he is in error in
stating that

"the

meteoric theory of the sun's heat must be abandoned." It is true that the larger portion of the solar heat is believed to be due to shrinkage, but it is generally conceded that a considerable fraction has its origin in falls of meteoric matter into the sun. A glaring case of the misuse of a scientific term occurs in this chapter (p. 52), where Mr. Gore is responsible for the statement that "the theory generally held by astronomers ascribes the heat of the sun to shrinkage of its mass caused by gravitation." Mr. Gore surely meant volume.

The chapter on celestial chemistry is meagre and unsatisfactory. It seems incredible that the application of photography to spectroscopic work is not even mentioned, and that no allusion is made to the Draper catalogue of photographic stellar spectra, to Rowland's photographic mip of the solar spectrum, or to any of the recent photographic work. Mr. Gore is also in error in this chapter when he states (p. 79) that although the great nebula in Andromeda " has never been resolved into stars the evidence of the spectroscope shows it is not gaseous." Bright bands have been seen in the spectrum by Backhouse Fowler, and myself, and these have been identified as probably due to carbon radiation.

The Meteoritic Hyp thesis is dealt with in considerable detail, and here Mr. Gore is most seriously in error. He gives what is professedly "a review of the principal facts and arguments advanced by Lockyer," and carefully enumerates all the objections that have been urged by "his opponents," ending the account with the opinion that "on the whole, therefore, we seem bound to conclude that the weight of evidence is against the truth of the Meteoritic Hypothesis." The chapter bears internal evidence that Mr. Gore began his consideration of this hypothesis with the opinion which he enunciates as his final judgment, already formed.

The summary of Prof. Lockyer's book has not been made with the care that should have been bestowed upon

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There are several errors due to histy compilation, observations and theories being attributed to Prof. Lockyer in cases where he only quotes the observations and adopts the theories. On p. 92 Mr Gore says "he (Lockyer) also finds line absorption in Comet Wells and the great September comet of 1882." This is misleading, the observations of absorption having been made by Copeland, Maunder, and Vogel. On p. 93 we find the "theory that the light of comets is due to collisions between the component meteorites" attributed to Prof. Lockyer. The theory is due to Reichenbach, Tait, and Sir William Thomson; Prof. Lockyer's contribution being the demonstration that spectroscopic observations lead to and support the hypothesis. The results of Tait's calculations given on pp. 227-229 of the "Meteoritic Hypothesis" are also attributed to Lockyer on p. 93 of Mr. Gore's book. On p. 95 we read, "the spectra of the true nebulæ consist of a very faint continuous spectrum crossed by one, two, three, or four bright lines" Lockyer gives seventeen bright lines in his table. Mr. Gore's footnote that "the complete hydrogen series of lines were

photographed by Dr. Huggins in 1890," in the great

nebula in Orion is also a mistake.

Mr. Gore has evidently failed to appreciate the importance of several portions of Prof. Lockyer's book, and has consequently omitted to mention them in his summary. Thus the observations of meteoritic glows recorded on pp. 49-51 of the "Meteoritic Hypothesis" are entirely passed over. In these experiments it was found that on slowly warming meteorites in a vacuum tube through which electric discharges were passing, the spectrum of hydrogen was first developed, then carbon was added, and the first line due to any metal was the 500 line which is the characteristic nebular line. Further heating gave the 495 line and then the B magnesium lines. These experiments, omitted in Mr. Gore's summary, are an effective answer to the objections of Messrs. Liveing and Dewar given on p. 116 of this book, for we have here the 500 line developed in presence of hydrogen, and at a lower temperature than the B lines.

Mr. Gore believes that "one of the crucial tests of the meteoritic hypothesis" is the question of the identity of the 500 nebular line with the magnesium fluting at this wave-length. He says (p. 86) that "it is on the identity of this fluting (or rather its brightest edge) with the chief line in the spectrum of the nebula that the meteoritic hypothesis mainly depends," and from pp. 118-121 it is obvious that he thinks the evidence conclusively against the hypothesis on this point.

In the first case the identity of the 500 nebular line with magnesium is not essential to the meteoritic hypothesis, although the latest observations have strongly supported the case for the identity. The main point is whether the 500 nebular line is due to high or to low temperature, and whether nebulæ are high or low temperature phenomena. Previous to the publication of Prof. Lockyer's book all cosmical bodies were believed to be cooling. The nebulæ were considered to be the hottest of all bodies, and on losing heat were supposed to pass into stars of the Sirian type. Further loss of heat converted them into stars of the solar type, and by still further loss they became red stars with banded spectra before reaching final extinction. This hypothesis was supplemented by Dr. Croll, who suggested that nebula were formed by the complete and almost instantaneous volatilisation of these dark bodies on collision, the heat generated by impact being sufficient for the purpose. Lockyer's hypothesis supposes nebula to be loose swarms of colliding meteorites. Condensation of these swarms by gravitation increases the number of collisions, and as the temperature rises we get stars with bright lines in their spectra. Further increase of temperature gives red stars of Secchi's III. class, which pass with still rising temperature into stars with fine absorption lines in their spectra, and so on until the Sirian type is reached, in which we have the highest temperature. Collisions have now ceased and the process of cooling begins, the stars passing into the solar type, then into red stars of Secchi's IV. class, and to final extinction.

The lines in the spectra of nebula and bright line stars according to this theory may be due to three causes. (a) Radiating vapours filling the interspaces between the meteorites; the lines of hydrogen and the bands of

carbon being due to these. (b) Low temperature li metals, due to grazing collisions of meteorites. (E) temperature lines of metals, due to direct collisions is essential to the theory that low temperature line metals should be found in nebulæ spectra, and the temperature origin of the 500 line seems clearly blished. Its chemical origin is of quite secondar portance. That it is due to low temperature is sho the experiments on meteoritic glows which Mr. omits; by its presence in comets away from the st observed by Huggins in 1866 and 1867 (this being only line present), by Vogel in Coggia's come.. Konkoly in the great September comet of 1882; an by the fact that it persists in all temporary stars as» temperature falls and is the last line to disappear. I these facts are explained away the foundation meteoritic hypothesis remains unshaken. Mr. Gorese unaware that this main point is now generally ade for although the low temperature origin of nebula denied by Dr. Huggins as late as 1889, it was ad in his Address to the British Association at Card 1892.

There is early evidence in the book that Mr. Ger entirely failed to grasp this essential point of the thesis. On p. 41, discussing Croll's impact theory t formation of nebulæ, he says, "according to Prof. La the temperature of the original solar nebula was as i as that of the sun at present." Mr. Gore word done well to have noted that on p. 528 of his book Lockyer explicitly states that "the temperature most prominent radiating vapours in nebulæ is i that of the Bunsen burner."

Mr. Gore's misconception of the theory and the in which he approached its discussion are also sho p. 101, where he says, "All these conclusions re course, on the supposed coincidence of certain lines: spectra of comets, nebulæ, and stars, with bright line flutings, a coincidence which has been disputed by observers. Relying, however, on the accuracy! experiments, Lockyer proposes a new grouping of cobodies. He supposes some of these bodies to be ing in temperature, while others-like our own str cooling." To this he adds a footnote, "Lockyer's rests on this assumption, but it should be stated some astronomers doubt that the sun is really co We should be glad to know who these "astronome: Mr. Gore himself is evidently not of their number, distinctly recognizes the sun as a cooling body chapter on the fuel of the sun, and specially ment as such on pp. 42 and 53. It is possible that Mr. Go misunderstood the apparently paradoxical fact thats in changing from a gas to a liquid, may rise in tes ture while losing heat, but that will not justify the style which leaves it to be understood by the g reader that Lockyer's curve rests solely on hist ments, and the "assumption" that the sun is cool that this fact is doubted by some astronomers. quite aware that Mr. Gore's expression will bear of terpretations, but this is the idea conveyed to s readers to whom we have shown the book.

Returning to the question of the coincidence of L nebular line with magnesium, the evidence recor Mr. Gore is in favour of, rather than against, the a

facts are:- Huggins finds the wave-length in the n nebula as 500475, the magnesium fluting being $5, a difference of 175. At the same time, Huggins s very little, if any, sensible motion in the line of sight. Keeler finds as a mean from 10 nebulæ 500568, nesium being, according to his measurement, 36, a difference of 68. These latter observations pletely invalidate Huggins's evidence on this t, especially as Mr. Keeler recognizes a motion ecession for the Orion nebula of 107 miles per nd.

r. Gore ought to have recorded the fact that in ler's observations the comparisons for different nebulæ the magnesium sometimes more refrangible and etimes less refrangible than the nebular line. Later ervations of Keeler, "corrected for the earth's orbital ion and the sun's motion," give the nebular line a wave;th of 5005 93, i.e. only 43 from the magnesium. uming Keeler's latest results as perfectly correct, and cing his position at Charing Cross, while representing position found for this line by Dr. Huggins in 1868 at Paul's Cathedral, we find Dr. Huggins's limiting posiis in 1889 as the extreme east and extreme west ends Green Park, his 1890 position in the middle of Green k, while the magnesium fluting will be at Cecil Street. en we consider that a motion in the line of sight of than twenty miles per second will make the nebular and the magnesium fluting absolutely coincident, that rate of the sun's motion in space is estimated but not olutely known, that these measurements are probably most difficult of all astronomical observations, and : every increase of power and accuracy has brought lines closer together, we are certainly not justified tating that the "weight of evidence" is "against the h of the hypothesis." The differences in recorded re-lengths of well-known solar lines by experienced ervers are in many cases greater than the difference question here.

1r. Gore regards the dispersion used by Prof. Lockyer nsufficient, and yet he records that sixteen prisms were d by Loc yer in some of his observations of the codence of the nebular line with magnesium, so that dispersion was actually greater than that used by Dr. gins, and two-thirds that of Mr. Keeler, whose version equalled twenty-four prisms.

he objections to that portion of the meteoritic hypois which deals with the meteoritic origin of the lines e auroral spectrum do not in any way affect the main othesis. That this subject is unimportant is distinctly gnized by Prof. Lockyer, "Meteoritic Hypothesis," 7, where he claims that "certainly the coincidence is as to justify us in regarding meteoritic dust as the in of the spectrum until a better and more probable in is demonstrated."

e are told (p. 122) that Mr. Monck objects to Ayer's hypothesis, because it contains no explanation why all the planets and asteroids and the great majority je satellites revolve in the same direction, why the ts of the larger bodies of the system deviate so little the circle and why they are so nearly in the same e." This was asked in 1890; and yet Prof. G. H. win had in 1888 shown that a swarm of meteorites h, on the meteoritic Lypothesis would form a nebula,

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may be considered as a gas, and therefore any answer that the nebular hypothesis can give to these questions will also apply to the meteoritic hypothesis.

Such puerile suggestions as that the meteorites used by Prof. Lockyer “may have been" of terrestrial origin : "that meteor clouds dense enough to produce the requisite amount of light by their collisions would also be dense enough to intercept a great part of it again on its way to the earth" (the italics are ours); and objections based on Mr. Monck's interpretation of Prof. Newton's calculations, and on opinions to which Mr. Monck "inclines" as to the origin of certain comets, are evidence that Mr. Gore has not hesitated to avail himself of anything that in any way seems to disagree with the meteoritic hypothesis. The whole of the "objections" of the "opponents" of Prof. Lockyer recorded by Mr. Gore are on matters of secondary importance, and have been insisted upon by him owing to his complete misconception of the theory. As a guide to the meteoritic hypothesis his chapter is misleading, and utterly valueless either as exposition or as criticism.

After his account of the meteoritic hypothesis Mr. Gore abruptly turns to a comparison of the various drawings that have been made of the Milky Way, and gives an interesting and valuable summary of the present state of our knowledge as to star distribution and movement and the construction of the Universe. For this portion of the book we have nothing but praise. It is carefully written and copiously illustrated. Mr. Gore has evidently taken the word "visible" in its widest possible sense, for he includes not only things visible to the retina of the eye, but those visible to the retina of the camera; and six excellent reproductions of photographs of nebulæ and stars clearly demonstrate the superiority of the latter for astronomical purposes. It is probable that the use of photography in the preparation of complete charts of the Milky Way will throw much new light upon many of the points discussed in this portion of the book, and may profoundly modify many of the views at present held; but in presenting a clear and concise account of the present state of our knowledge Mr. Gore has made a valuable addition to the literature of the subject. An appendix, in which are given various calculations and tables involved in the discussion of several points raised in the book, and a useful index, complete the volume. A. TAYLOR.

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cusses at length the American policy of protection. Comparison is made of American exports as affected by British free trade. Then follows a series of short articles on various subjects-the Anglo-American, imports of tinplates from this country, imports and exports of both countries, America as consumer and as exporter, and other important matters. By way of illustration copious tables are adduced with the author's deductions therefrom, and these will well reward the closest attention.

Section 2 deals with the relative cost of the necessaries of life in various mining and metallurgical localities :

sumers.

"In the United States the manufacturers are enriched at the expense of the agriculturist and of other conSome time before the abolition of protective duties in the United Kingdom years of scanty harvests entailed a great amount of misery among the labouring population of these islands, and at all times the landed interest by the protection granted to it by law, imposed a burthen upon industry generally. This relation between land and industry is now, as we have seen, reversed in the United States, by which, according to our views, the manufacturers are enriched at the expense of the agri

culturists and of other consumers.

"Circumstances have greatly changed since the repeal of the corn laws, and the general introduction of free trade in the British Isles, for we have a people, the largest food importers in the world, obtaining their supplies 3000 miles from where they are grown, frequently at prices as favourable as those charged in the cities of America itself."

Sir Lowthian Bell appears to grasp fully a difficult situation, and gives a fair summary of the relative economic position of the two countries, and though his views will hardly be endorsed in their entirety by Americans, the present statement of them cannot fail to strengthen the movement now in progress towards a modification of the existing fiscal policy.

It is somewhat out of our province here to comment upon the protective policy so ardently advocated in America, but we are of opinion that had iron manufacturers in the States adopted, even partially, our policy of free competition, they and their employés would now have been in a stronger position, and would have had a better prospect of successfully competing with us. It is possible that the very natural desire to foster the home industry has carried them a little too far.

In the next section the assemblage of materials on American is compared with that on British railways in an exhaustive manner.

Section 5 treats of the iron ores of the States, and is fully illustrated with maps, topographic and geological, together with the coal fields. The quantities raised at different periods are given, and show that in ten years the production of ore has been fully doubled. This is followed by a detailed account of the mines and costs of working. Pages 96-104 contain some interesting speculative matter on the genesis of iron ores; the cost of raising ore, together with chemical analyses, is compared with that of Great Britain and other countries. The importance of having iron free from phosphorus is shown. It is noted that iron ore suitable for the Bessemer acid process has been imported. In 1880 only 27 35 per cent. of native ore was deemed suitable and raised for this purpose.

Treating of raw material in the States, the writer a vivid picture of the boundless wealth of both cre fuel existing within a limited area. In the great district there is a wide strip of country over 1000 long, where ore is found, and this is insignificant compared with the immense resources of fuel. The of natural gas, petroleum, and its uses receive atte -"natural gas is not a suitable form of fuel for the furnace."

Section 9, on the manufacture of coke, is inters At the outset coke is defined and compared wit analogues-anthracite or native coke. The losses 25 sarily entailed in the manufacture of coke are diste together with modes of minimizing them. It is s that it is impossible to utilise the gases evolves coking or heating coal in the blast furnace, and slowly this was realized in early practice.

Here the author's ripe experience comes inte The rationale of coking is tersely put, together w methods dealing with the utilization and recovery ammonia, tar, &c., the products of the destructive lation of coal, "or coking," with special appl. adapted for this purpose. The comparative mer hard and soft coke in the blast furnace are disc Commercial details are appended, which speci themselves, and which appear accurate.

From the section on the manufacture of pig ind may be gathered that the gigantic methods of proce and the enormous energy diplayed in the business American iron manufacture, leave the average ca Englishman in the rear. There is, however, the re side for consideration it is questionable whether: the magnificent results before us have not been purc at too great a cost. Enormous quantities of ironwithout doubt been turned out, such as would nevert been dreamt of here; but it would seem that auth are not yet in agreement as to the relative mer English and American practice. So far our Are cousins appear satisfied, pointing triumphantly: saving of both time and material accruing froz present practice. At the Edgar Thompson Works 170) one of the furnaces ran 2462 tons of iron week, and showed an average make of 2813 to week with an expenditure of only 16·80 cwts. of c ton of iron. One needs, however, only to take S Bell's elaborate demonstration of the laws which the consumption of fuel in the blast furnace, a utilization for the reduction of the ore, to see clear the above production is scarcely in the domain of pri work, carried out under ordinary conditions with a ores and fuel. Also (p. 162) he remarks, if Great! fails to offer striking examples such as are descrit Mr. Potter and Mr. Gayley, yet, all things conside more uniform as well as loftier pitch of excele British furnace work can be proved.

Our space does not admit of a complete ment of Sir L. Bell's proofs; shortly, he first tab the work done at Middlesbrough with that of the burg blast furnace, and absolutely demonstrates !! large makes are not altogether due to superior pr A perusal of the tabular statement given satisti accounts for the larger consumption of fuel in the E I furnace.

The poorer ore of Cleveland consumes 3:48 cwt. of e, as against only 142 cwt. in the richer ore used at sburg for the future of the slag.

The quantity of slag determines the fuel required for consumption, and here is the chief difference in the ount of fuel required, amounting to 2:06 cwts. The rence furnace consumed 1999 cwt. of coke per ton of ; the Pittsburg furnace consumed 16 80, difference , and deducting 2'06 from 19'99 cwt. = 17'93, showan excess of 113 against the English furnace. This ractically the only margin we have for economy in other sources of waste tabulated in Sir L. Bell's parison of heat distribution.

positive saving is effected of only 113 cwt., and ons are given showing that, all things considered, this ⚫ be counterbalanced by the increased expenses ined in American practice. As instance pp. 172-174 e are now four furnaces in action at the Clarence ks performing duty well after 17 years' service, as inst the hard-driven furnaces in America with lining n out, and useless in one-sixth of the period.

he limitation is well-defined in the following words, 182-183

As one who has been fifty years at blast furnaces, greatly impressed with the pitch of excellence vhich the Americans have brought this useful inion.

While saying so much I have not in my mind the mous makes.

In respect to this we must remember that neither in erials nor in labour can we look for any economy in country.

On the subject of large makes I must admit that I d to shake the belief of my friend, Mr. E. C. Patter, there is a great advantage in tasking the endurance he furnace to the extent of reducing it to a wreck it every three years.

I cannot say I am quite a convert to his creed, but nt experience, and the unswerving conviction of my erican friends, have raised in my mind the disposition nake a trial of Cleveland ironstone, on what I have ight a questionable mode of action."

he question of heat intensity, or actual temperature, ch must vary with the rate at which the fuel or coke nsumed, has not been mooted, and we admit there is ositive reason why it should.

t it is evident that a certain fuel-coke, for instance ty be so burnt as only to give a heat intensity barely ing for the fusion of lead. On the other hand, it be so manipulated, i.e. rapidly consumed by a draught or forced blast as to attain a heat sity (temperature) sufficing for the fusion of pig

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orking with high pressure blast and driving in a volume of air (87'15 cwts. Clarence, as against 71'20 Pittsburg, see p. 172), the heat intensity must be er in the latter instance, and must," according to aw of heat exchanges," result in the more rapid >mic fusion of iron in the hearth, also intensifying the chemical reactions. This seems worth consideratemperature is an important factor-in saying this st not be inferred that the estimation of the calorics a given fuel evolves, and their distribution, must be

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The Fauna and Flora of Gloucestershire. By Charles A. Witchell and W. Bishop Strugnell. (Stroud: James, 1892.)

IT T would really be almost difficult to discuss this book serious spirit were it not that the publication of so ambitious a work as the Natural History of a County must always be regarded as a serious undertaking. The reader who has struggled through the volume will lay it down with a sigh-not of regret at leaving it, but at the thought that time has been wasted in its compilation.

A glance at the index is almost enough to condemn the book, without making any attempt at further acquaintance. Among nearly a score of errors in spelling, subuteo, oesalon, tinninculus, occur as three consecutive words. Nor is this carelessness by any means confined to the index. Such blemishes disfigure the book from beginning to end; and when, among a host of errors, we find such mistakes as haliotida and helliborus, we can hardly ascribe all the blame to the printer. The compilers usually give us introduction the name is spelt "Cotswold," and there compilers usually give us "Cotteswold," but in the are pages on which both forms occur-in one case only a line apart.

We

A more serious fault is the want of balance in the work. The space allotted to birds occupies eighty-two pages, while the chapter on ants takes up nearly twenty, and that on wasps and bees close upon fifty pages. may say at once that the two latter are so good, and stand out in such marked contrast to the rest of the work that, in spite of their disproportionate length, we hardly grudge a line of the room they occupy. Perhaps, however, it is the length of these papers which makes one of the writers on mosses omit "many other interesting species," for want of space. Another contributor calls his list of fungi "short and very imperfect." If the list is as complete as it is possible to make it, no one can fairly complain of its shortness; but surely it is scarcely worth while to print an avowedly imperfect list in what professes to be a County Flora.

The fauna opens with a brief account of the bats, a mere list of names, among which we look in vain for any evidence of observation. The notices of the quadrupeds contain some interesting particulars, but they present little that is new. In the article on the badger a good deal of information is given on the authority of a gentleman who appears to think no observations but his own are worthy of credence. One of his own observations is thus worded: "Any one who has caught badgers at night knows only too well that it is certain death to a dog

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