Mvv 1. lOOOl 



KNOWLEDGE 



m 



nebulosities will eniirely Uisiippear from view.'' This is a factor 

 that should certainly be borne in mind by the directors of those 

 observatories which are takins; part in tlie work of international 

 chartin;;, for tlioui;h the cost of reproduction of all the plates on 

 paper print with permanent ink may be considerable, it is insij;nili- 

 cant when compared with the cost of procurinir the original 

 neiratives which may thrimsih lapse of time become valueless. 

 Though we may be assured that in these photofrr.iphs lie hidden 

 the solution of many problems that have not been even stated as 

 ret. the mere superficial investisration of one of these photo>;ra)ihs 

 set'ms to indicate many avenues for investixation. Four or live 

 hours were spent in the study of one selected almost at random, and 

 a few of the forms and contisrurations depicted in it were fcjlUnved 

 out. Cluster H VI. 5 Orionis which is reproduced in Plate 2 is 

 by no means one of the most striking photographs in the vohime. 

 It is no huge cluster, and no trace of nebulosity could be discovered. 

 To the astronomical eye, however, its star images are objects of 

 extreme beauty, being veiy small and perfectly round, the fainter 

 stars looking like needle points of white on the dark b.iclcgrouml. 

 In the s.f. corner of the Plate there is one of the most ])crfecfc 

 spiral of stars that we have ever seen. Xo vestige of nebulosity is to be 

 seen stretching in the spaces between (he stars which curve through 

 seven distinct widening convolutions round the large star which 

 is evidently the central condensation of the original spiral nebula. 

 The stars vary greatly in magnitude, large and small being inter- 

 twined in the convolutions without ajiparent law. From its appear- 

 ance the stellar spiral is a left handed planar not a helical one, and 

 its plane is not far from being perpendicular to the line of sight. 

 The whole is like the sevenfold coil of a huge serpent covering some 

 20' of arc in the sky. In the centre of the plate is another spiral 

 of stars of a different species, and not of so distinct and perfect a 

 nature. Here can be diiidy made out a series of spirals which 

 radiate from a common centre like the feelers of the cuttle lish. 

 Following this central cluster by about 16' to 21 ;u'e two other 

 clusters which Dr. Roberts says are suggestive of a s|iiral origin. 

 A close examination indicates that these two clusters are not distinct 

 but form part of the same helix of stars (which is a very perfect one). 

 The apparent clustering seems due to the oblique presentation of 

 the helix, which might be represented by three turns of a corkscrew. 

 In this spiral the stars do not appear to present so great a range of 

 magnitude as in the other two describee!. These three do not by 

 any means exhaust the spiral forms which are to be found in tliis 

 very wonderful photograph. In every region of the Plate are to he 

 found spiral systems under some type or ijresentation. We heartily 

 congratulate and thank Dr. Roberts for his issue of these beautiful 

 and valuable photographs. 



'■ Animals in Jlotion." An Electiopbotographic Investigation 

 of Consecutive Phases of Animal Progressive Movements. By 

 Eadweard Muybridge. (Chapman and Hall.'l 2Us. net. Of all 

 the results which have followed tho introduction some quarter 

 of a century ago of photographic methods into scientifi.-. 

 research, the knowledge of animal locomotion which Mr. Muy- 

 bridge has given to the world is certainly not the least impor- 

 tant and interesting. Like many other investigators, Mr. 

 Muybridge was put upon the track of his future elaborate 

 experiments bj- a very simple incident As he tells the reader 

 in his preface, he was in the spring of 187i! directing the photo- 

 graphic surveys of the United States Government on the 

 Pacific Coast, and being in San Franci.sco he took part in a 

 controversy, the pi incipal subje -.t of which was the possibility 

 of a horse while trotting — even at the height of its speed — 

 having all four of his feet, during any portion of his stride, 

 simnltaneously free from contact with the ground. Mr. 

 Maybriilge resolved to attempt the settlement of the question, 

 and though the days of the rapid dry photogra])hic process had 

 not yet come, he was soon at work with wet collodion plates. 

 He commenced his investigation on the race-track at Sacra- 

 mento in May of the same year, and in a few' days made several 

 negatives of a horse trotting literally in front of his camera at 

 varying speeds ; some of the resulting photograjdis exhibited 

 the horse with all four of his feet clearly lifted, at the same 

 time, above the surface of the ground. The next step was to 

 obtain a series of photographs in rapid succession at properly 

 regulated intervals of time, or distance, so as to discover the 

 true explanation of animal movements. After designing 

 special apparatus and utilising the leisure hours of a busy 

 official career, Mr. JInybridge was able in 1878 to deposit at 

 ■Washington Congress Library sheets of jihotographs illustiating 

 consecutive phases of one complete stride of a horse, while 

 walking, trotting, galloping, and so on. Then came the con- 

 struction of the zoiipraxiscope, an instrument for synthesising 

 the actual image from these separate impressions. The dis- 



covery of celluloid ribbons, which made it possible to obtain a 

 larger number of successive phiises of motion, led the way to 

 Edison's kinetoscope. But all these successes l\lr. Muybridge 

 regards as preliminary work to tho production of bis uiastorpiece 

 of 1887, known as •'Animal Locomotion,'' and containing more 

 than 'iOjiltUt figures of moving men, women, children, beasts, 

 and birds, in 781 photo-engraviiios, bound in eleven folio 

 volumes. Tlie possibility of taking the luiiidrcMl thousand 

 plates which were used in'the iireparatiou of this monuinciital 

 work, and of publishing it, was due to the public-spirited action 

 of the University of Pennsylvania, which undertook the 

 expense. The volume uiuh:r consideration comprises a selec- 

 tion of the most important plates contained in the larger 

 volume on a reduced scale, and should be in the bands of every 

 student of science and art, since the plates furnish a trust- 

 worthy guide to tlie laws which control animal movements. 



"A Book of Whales." Bv F. K. Beddard. Progressive Science 

 Series. (Murray.) 1900. "illustrated. 6s. The huge boilily 

 size of its more typical members, the few ojiportunities that lands- 

 men have of seeing them, coujiled with the fact that, in spite of 

 their generally lish like form, tliey are warm-blooded animals, sur- 

 rounds the group of Whales, or cetaceans, with a halo of mystery 

 and fascination wdiich cannot fail to attract general interest. It is, 

 therefore, most satisfactory to have a popular and succinct account 

 of the grouj) from a writer wlio lias evidently worked hard at his 

 subject and brought together almost all that is worth knowing con- 

 cerning the structure and inoile (jf life of these strange creatures. 

 Taken as a wliole, it niav be said that Mr. liedilard's treatise is all 

 that can be desired, and that it is likely to remain for a long time 

 the standard poi>ular work on the subject. To a certain extent it 

 is more than this, for it enters on the consideration of many 

 technical details — notably as regards the number of species, and 

 the alHnities of the various genera. Indeed, there may be aipiestion 

 whether the author has in all cases descended to the level i>f his 

 readers, the xise of terms like " thoracic niusi^ulature " when 

 " muscles of the chest " would have served the purpose better, 

 being calculated to mystify the uninitiated. Kspecially is this 

 noticeable in the section devoted to osteology, where the ordinary 

 reader is likely to be puzzled as to the exact meaning of terms 

 like "acromion" and " coracoid process." And since figures of 

 manv bones are given, the difficulty could have been so easily 

 avoifled by the addition of descriptive letters. Confusion is also 

 made by Hguring in Plate IV. tympanic bones of the Right ''■Vliale 

 and the Ronpial wliicli belong to ojjposite sides. If we were dis- 

 posed to be critical we could point out a good many typographical 

 and grammatical blemishes ; but in regard to errors of this de- 

 scription we will be content with asking our readers to compare the 

 figure of Bahena australis facing page 22 with the cast in the 

 Natural History Mu.seuin, from which it is taken, when we venture 

 to atlirai that a surprise will await them. 



Among the more interesting features of Whales are the numerous 

 "vestigial" structures to be met with, such as the functionless 

 teeth of ftt'tal Rorquals, and the bony plates on certain Porpoises. 

 That Cetaceans had toothed ancestors, everyone was prejiared to 

 admit, but that their progenitors should luive been mail-clad 

 animals is indeed a "staggerer." But it is very difficult to come 

 to any other conclusion. And this leads to a puzzle, for the only 

 mammals that are known to possess such an armour are tlie 

 Armadillos and certain other Kdentates, which are in no sense 

 ancestral (,'etaceans. Here, we regret to say, the author is not 

 quite so clear as is desirable. While of opinion that both the 

 'VV'halebone and the Toothed Whales have a common ancestry 

 (p. 106), he .seems undecideil whether to regard such ancestry as 

 connected with the Sirenia or the Ungulata,. But if a dermal 

 armour were present, it is quite certain that suih ancestry had 

 nothing to do with the sea-cows, while it is difficult to see where the 

 ungulate connection could have come in. Apparently Mr. Beddard 

 will h.'ive nothing to do with a carnivorous ancestry for his 

 favourites ; although if this view were accepted the arnmur diffi- 

 culty remains in full force. 



An important feature in the work is the atteiilion jiaid to fossil 

 forms, and although the reference to these is for the most part 

 satisfactoiy, exception may be taken by some to the statement that 

 Whalebone Whales do not antedate the Miocene. Being in a 

 charitable mood, we will assume that the statement on I'age 20 as 

 to the derivation of Whales from Rejitiles is a la|isus calami : but 

 we must take excejition to the one on ])age 220 — that the Sabre- 

 toothed Tigers were hindered by the conformation of their tusks 

 from opening their mouths to the fullest extent ! 



In some parts, too, the author appears unnecessarily sceptical, 

 as for instance when I p. 199) he refuses to credit the statement 

 that the Sperm Whale drops its lower jaw when feeding. Mr. 

 Bullen's observations in the " Cruise of the ' Cachalot ' " ought 



