116 



SCIENCE. 



[N. S. Vol. XXII. No. 552. 



feature. Commendable also is the effort 

 throughout to render clear the meaning and 

 limitations of cardinal theorems. We doubt, 

 however, whether the vexed question whether 

 a variable may attain its limit is, in spirit, 

 quite settled by the ingenious example given 

 on page 20. 



The Boston Colloquium consists of three 

 sets of lectures: three by Professor White on 

 ' Linear Systems of Curves on Algebraic Sur- 

 faces ' ; three by Professor Woods on ' Forms 

 of ISTon-Euclidean Space ' ; and six by Pro- 

 fessor E. B. Van Vleck on ' Selected Topics 

 in the Theory of Divergent Series and Con- 

 tinued I ractions.' The lecturers being all of 

 them former pupils of Professor John Monroe 

 Van Vleck recently retired from the chair of 

 mathematics and astronomy at Wesleyan Uni- 

 versity, where he had served for a period of 

 fifty years, this volume of lectures is inscribed 

 to him. Each set of the lectures affords a 

 compendious account of the advanced thought 

 in its field, together with indications of exist- 

 ing problems and of the directions that fur- 

 ther immediate developments will probably 

 follow. The lectures being of highly tech- 

 nical character and being addressed to special- 

 ists, any adequate account of them must be 

 reserved for journals specifically devoted to 

 mathematics. Cassius J. Keyser. 



Columbia University. 



NeudrucJce von Schriften und Karten uber 

 Meteorologie und Erdmagnetismus heraus- 

 gegeben von Professor Dr. G. Hellmann. 

 No. 15 (Schlussheft). Denhmdler Mittel- 

 alterlicher Meteorologie. Berlin, A. Asher 

 & Co. 1904. 4to. 46 pp. introduction + 

 270 pp. reprints + 12 pp. addenda and er- 

 rata to previous numbers. 

 The publication of this volume, which is the 

 fifteenth and final one of the series, affords an 

 opportunity to congratulate Dr. Hellmann 

 on the completion of so admirable a biblio- 

 graphical work, which offers to students the 

 advantage of reading in their original form 

 many epoch-making papers relating to meteor- 

 ology and terrestrial magnetism. Readers of 

 Science are familiar with the nature of these 

 reprints from the reviews that have appeared 



in Vol. I., p. 302; Vol. IX., p. 910; Vol. XIII., 

 p. 821; and Vol. XVI., p. 352. Five of the 

 earlier volumes demonstrated that meteorology 

 was actively cultivated in the fourteenth, fif- 

 teenth and sixteenth centuries, but in the 

 present issue it is seen that much earlier, and 

 during the entire middle ages, meteorological 

 questions were continually discussed. As il- 

 lustrations there are given, in part or in ex- 

 tenso, 26 writings, dating from the seventh 

 to the fourteenth centuries, inclusive, among 

 them the following examples of famous au- 

 thors : ' De Natura Rerum,' by Isidorus His- 

 palensis and Beda Venerabilis; two papers 

 by Albertus Magnus ; Roger Bacon's ' Opus 

 Majus,' and ' De Proprietatibus Rerum,' by 

 Bartholomseus Anglicus. Most of the treatises 

 are taken from printed books, but a few are 

 printed from manuscripts for the first time. 

 Certain tracts that were written in little- 

 known languages have been translated into 

 German and so are made accessible to a wider 

 circle of readers, but those in early French, 

 Italian and Dutch appear in the original 

 tongues. It is hardly necessary to say that 

 the facsimile reproductions have been made 

 with the same care that characterized Dr. 

 Hellmann's previous reprints, for the accuracy 

 of which the writer can vouch, having com- 

 pared several with the originals in his own 

 possession. Their value is much enhanced by 

 the explanatory and bibliographical notes 

 which accompany each. 



One or two copies of this last volume have 

 been placed on sale at the Blue Hill Observa- 

 tory, Hyde Park, Mass., and will be sent on 

 receipt of the publisher's price, viz., 28 Marks, 

 or $7. In conclusion it may be stated that at 

 least four of the earlier volumes are already 

 out of print and command high prices. 



A. Lawrence Rotch. 



SCIENTIFIC JOURNALS AND ARTICLES. 



The last number of The American Journal 

 of Mathematics contains the following ar- 

 ticles : 



G. W. Hill : ' Deduction of the Power Series 

 Representing a Function from Special Vahies of 

 the Latter.' 



