442 



NATURE 



{April A,y 1872 



meteorology still impressed with the idea that, with a 

 correct knowledge of what has baen, we may be able to 

 form an opinion of what is to be. It seems to us by no 

 means improbable that with more accurate information, 

 such as this now being stored for future use, we may 

 before long arrive at the power of foretelling the general 

 character of seasons, in regard to their being wet or dry, 

 hot or cold, stormy or gentle ; but we see no reason to 

 believe that any amount of study of the past will ever 

 enable us to predict in detail for any length of time in 

 advance, though it may and must lead us to a better 

 capability of rightly interpreting the atmospheric changes 

 going on, of detecting them at their earliest beginning, of 

 judging their probable effects, and thus of extending the 

 period for which " storm warnings " may be made 

 available. With increased experience new power will be 

 gained, new methods will be learned and proved. Even 

 now, the spectroscopic observations by Commander 

 Maclear, to which he called our attention in these 

 columns only a fe v weeks ago, seem to point hopefully 

 towards a new path in meteorological research ; for it is 

 not only in the widely different climate of the Bay of 

 Biscay, the Red Sea, and the Indian Ocean, that he 

 observes the differences in the spectrum which he has 

 spoken of in the article just referred to ; he informs us 

 that his later observations lead him to believe that the 

 changes in the atmospheric humidity distinctly correspond 

 to changes in the solar spectrum ; that, for instance, an 

 increasing humidity manifests itself by a shortening in of 

 the blue, and by a well marked development of aqueous 

 bands in the red and yellow. Whether further examina- 

 tion will confirm this belief or not it is at present impos- 

 sible to say, but the spectroscope has done so much 

 towards teaching us the cons'itution of other atmospheres, 

 that we may fairly entertain a hope that the time has 

 come for it to teach us something about the distant and 

 outlying parts of our own. J. K. L. 



Index of Spectra. By W. I\I. Watts, D. Sc. (London : 



Henry GiUman.) 

 All workers with the spectroscope must have felt the 

 great inconvenience arising from the employment of num- 

 berless different scales in the mappirg of spectra. It is 

 to be hoped that at some future time there will be more 

 uniformity, and that authors, when publishing original 

 memoirs, will reduce their measurements to a definite and 

 recognised system. It is clear that such a method must 

 be perfectly independent of the spectroscope and its con- 

 comitant parts ; the position of each line can therefore 

 only be expressed by its colour, or, in other «'ords, by the 

 length of the wave of light which produces this colour. 

 Dispersion spectra, obtained by the use of prisms of 

 different materials, vary greatly in the relative breadth of 

 the respective colours ; thus in the spectrum from crown- 

 glass the red end is larger and the blue end shorter than 

 in the spectra obtained from flint-glass, carbonic disul- 

 phide, and by diffraction. It is therefore necessary in 

 spectroscopic researches to record the positions of 

 numerous well-known lines as observed in the instrument 

 that is used. In a diffraction spectrum, however, the 

 position of the lines is dependent solely on their colour, 

 and is precisely the same by whatever method the spectrum 

 is obtained. For the results of different observers to be 

 accurately comparable, the readings obtained by dis- 

 persion must either be expressed in wave-lengths, or the 

 spectra must be obtained by diffraction. The wave-lengths 

 of the Fraunhofer lines of the sun have been accurately 

 determined by several observers. The author has adopted 

 as the basis of his work the measurements made by 

 Angstrom, as these appear to exceed in accuracy all 

 similar measurements at our disposal. When ihe wave- 

 lengths of a number of lines are known, it is easy to cal- 

 culate the wave-lengths of the lines of any new spectrum, 

 either by the interpolation formula given by W. Gibbs 

 Phil. Ma^. [4] xl.157) or by the method of graphical inter- 



polation.both of which methods are explained in the volume 

 before us ; all that is required is to have the wave- 

 lengths of two known lines, between which the line to be 

 measured falls. By the aid of Angstrom's measurements 

 the author has reduced the measurements of the bright 

 lines of all the elements whose spectra have been carefully 

 investigated, and also of air lines as mapped by Thaler, 

 Huggins, and Plucker. These tables will therefore assist 

 materially in the work of reduction, by serving as land- 

 marks from which to calculate the wave-lengths of new 

 lines. The attention that the author has bestowed on 

 this work is the best guarantee of the accuracy of the 

 numbers given. In the lithographic plates at the end of 

 the tables, a drawing of the specrum of each element is 

 given on the plan proposed by Bunsen, in which the in- 

 tensity of a bright line is indicated by the height of the 

 line representing it ; a chromo-lithograph is given of the 

 double spectra of nitrogen, sulphur, and carbon, and 

 another plate, showing two spectra obtained by Wiilner 

 from aluminium, and three from hydrogen at different 

 powers. Dr. Watts is deserving of the best thanks of all 

 those interested in spectroscopic work, for it is to be 

 hopsd that his "Index of Spectra" may contribute to 

 the adoption of a uniform scale of measurement, and thus 

 facilitate the advance of the science. A. P. 



LETTERS TO THE EDITOR 



\Tke Editor does not Jwld himself responsible for opinions expressed 

 by his correspondents. No notice is taken of anonymous 

 communications. ] 



The Adamites 



Philologists will notice with regret a paper bearing the 

 above title in the late number of the Journal of the Anthropo- 

 logical Institute. The author appears to have taken up, without 

 proper study, that difficult and dangerous line of argument, the 

 comparison of historical names, and has naturally fallen into the 

 network of delusive fancy which in past generations entangled 

 Jacob Bryant and Godfrey Higgins. Modern philology has 

 abundantly proved that slight, loose, and occpsional correspon- 

 dences in proper names are deceptive as evidence, even among 

 languages of the same family, much more among languages of 

 different families. It is a fair sample of the present paper, that 

 it argues an affinity between the peoples of the Old and New 

 Worlds on the basis of a connection between various names of 

 the Deity, among which are the I-iussian Bog, the Mantchoo 

 Ab-ka, and the Hottentot Tcqoa . The special purpose is to 

 prove that nations are shown by their names to trace descent 

 from an ancestor called Ad — ^^ Adam, or Father Ad." Thus 

 " the great Hamitic race of .Akkad" is interpreted by the aid of 

 Welsh i7("// — root, lineage," so as to mean "sons or lineage of 

 Ad ; " and the name of Ta-ata, the Polynesian First Man, is 

 *'that of the mythical ancestor of the Adamites, reversed, how- 

 ever, and with the addition of ata [aka], spirit" ! It is obvious, 

 though unaccountably overlooked in the paper, that two of the 

 clearest cases of the theory may be found near home. The 

 descent of two nations from Father Ad is perfectly recorded by 

 ourselves, when we call the representative of one a Paddy, clearly 

 Ap-Ad (from .-//, " used in the sense of son''), while the other's 

 Adamite ancestor is commemorated by calling his descendant a 

 Ta.3'- 



It is not necessary to give the name of the author of this un- 

 lucky paper. Everybody is liable to slips, great or small ; and a 

 man may have done work worth doing in one line, but turning 

 suddenly to another, may come to grief utterly. But the Council 

 of the Anthropological Institute should have consulted their own 

 interest and that of their contributor by declining to print the 

 present essay. It is the duty of a learned society to examine 

 even a hasty and ill-considered idea brought forward by one of 

 its members, but not to put it on public record against them- 

 selves and him. M. A. I. 



The Segmentation of Annulosa 

 In the extract from his Address to the Entomological Society, 

 given in Nature, February 29, Mr. Wallace remarks that Mr. 

 Spencer's views have not been so much as once alluded to in the 



