314 



NA TURE 



\^Fcb. 4, 1886 



admirable ; a brief sentence is frequently found to 

 contain an accurate and vigorous expression of an 

 elaborate point. On page 3 we are told that "ob- 

 servation is the pitiless critic of theory." We are 

 told that the probability of 61 Cygni forming a con- 

 nected pair is actually greater than the chance of the 

 sun rising to-morrow morning. We read of incon- 

 spicuous minor planets being difficult to detect " in the 

 majestic disguise of a distant sun." We are told how 

 Prof. Adams would not " take any steps to obtain a pub- 

 licity which he was more anxious to merit than to secifre." 

 In referring to the same event. Miss Gierke describes 

 how Lalande narrowly escaped the accidental discovery 

 of Neptune, and adds : " An immortality which he would 

 have been the last to despise hung in the balance ; the 

 feather-weight of his carelessness, however, kicked the 

 beam." In speaking of the moon and the possible varia- 

 tions of lunar objects. Miss Gierke says : " A change 

 always seems to the inquisitive intellect of man like a 

 breach in the defences of Nature's secrets, through 

 which it may hope to make its way to the citadel." 

 There are charming bits of biography through the book : 

 as of Olbers, who became a mathematician because he 

 was an astronomer ; of Encke, who became an astro- 

 nomer because he was a mathematician ; or of Schwabe, 

 who, seeking his father's asses, found a kingdom. 



There are, however, some few omissions, for which we 

 hope in a future edition room will be made. We should 

 have an account of Briinnow's work on stellar paral- 

 lax. We think also that a history of modern researches 

 on double-stars should include a notice of Dembowski's 

 most elaborate observations ; while the labours of 

 Doberck deserve notice, as we owe to this indefatigable 

 astronomer the greater part of our knowledge of the 

 binary-star orbits. Miss Gierke has, however, fully appre- 

 ciated the splendid work of S. W. Burnham, who has in 

 ten years discovered 1000 double-stars. Those who are 

 aware of the magnificent labours of Prof Rowland, of 

 Baltimore, on the solar spectrum will be disappointed in 

 not finding some reference in a work of this kind. It 

 must, however, be admitted that a complete account of 

 Prof Rowland's work has not yet been published. 



Miss Gierke's most admirable work fills a widely-felt 

 want. The progress of spectroscopy has been recently 

 so rapid that it was often difficult to find out what was 

 known and what was unknown. It is here that Miss 

 Gierke renders an assistance that every astronomer must 

 appreciate. He can in this volume obtain a vivid and 

 accurate summary of what has been done, or, if he prefers 

 to read the original memoirs, he will be directed where 

 to find them. The work has been most skilfully and 

 faithfully executed, and we heartily recommend it to 

 every one who is interested in the noblest of the sciences. 

 Robert S. Ball 



CRANIOGRAPHY 



Einc exacte Methode der Craniographie. Von Dr. C. 



Rieger. (Jena : Verlag von G. Fischer, 1885.) 



*HIS work contains the description of a method of 



craniography employed by the author for upwards 



of five years for obtaining exact geometrical drawings 



T^ 



from the skull or from the head of the living person. The 

 first question dealt with by the author is the plane of 

 orientation of the skull to be adopted. He discards all 

 those which have for their aim the placing of the skull or 

 head in the position natural to man, namely, with 

 the axis of vision as nearly as possible horizontal, and 

 prefers a plane determined by anatomical considerations 

 alone. After studying different anatomical points on the 

 skull for this purpose, he came to the conclusion that the 

 most suitable is a plane running along the base of the 

 cerebrum, extending in front from the angle which the 

 horizontal and vertical portions of the frontal bone make 

 internally with one another to the upper border of the 

 sulcus transversus of the occipital bone, the attachment 

 line of the tentorium cerebelli. This plane placed hori- 

 zontally is the orientation of the skull adopted by the 

 author. He then proceeds to consider the question of 

 how far the proposed horizontal corresponds to the base 

 of the cerebrum ; and secondly, whether it can be deter- 

 mined on the periphery of the unopened skull or the 

 head of the living. Sections of the skull show that the 

 plane corresponds fairly in front with the base of the 

 cerebrum, but posteriorly there is an elevation of the 

 anterior part of the cerebellum and ganglia, so that it 

 does not follow exactly the line of the cerebellum, though 

 roughly it may be said to do so. The determination ol 

 the points on the exterior which correspond respectively 

 to the anterior and posterior ends of the plane or long 

 axis of the skull is of greater importance. The anterior 

 point is defined as that point where a line joining the 

 upper borders of the orbits crosses the median line of the 

 skull. The posterior point is more difficult to define, as 

 here several anatomical questions are involved, such 

 as the relation of the protuberantia externa to the 

 interna, and whether the latter corresponds to a fixed 

 point externally. From his investigations the author 

 found that the position of the attachment of the tentorium 

 on which the posterior end of the cerebrum rests cannot 

 be exactly determined in the unopened head or skull, but 

 the variations in position of the external and internal 

 protuberances in comparison to the whole cranial space 

 are so small that the error is infinitesimal. Both in the 

 skull and in the living the termination externally and 

 posteriorly of the plane may be taken as that point where 

 the linea semicircularis superior intersects the protuber- 

 antia occipitalis externa in the middle line, or in the 

 living immediately above the line of attachment of the 

 muscles. Having determined these points, he proceeds 

 to show that the outlines of the dimensions of the skull in 

 relation to this plane can be taken only with the assist- 

 ance of ordinates standing at right angles to one another. 

 He has satisfied himself that it is necessary to have 

 complete outlines of the whole of the curves, and not only 

 the greatest dimensions, so that a model of the skull from 

 which they are taken can be at once apparent. Only a 

 few of the most important curves require to be taken in 

 every case : these are a curve of the ground or horizontal 

 plane, of the median plane, and a third transversely over 

 the cranium in the plane of the external auditory 

 meatus. 



The method of obtaining the curves is as follows : — 

 Two threads are tied in the centre so as to form a cross ; 

 each end is weighted with lead. The knot is placed lis 



