628 



SCIENCE. 



[N. S. Vol. V. No. 120. 



fully renders the fundamental formula cos a= 

 cos b cos c + sin 6 sin c cos A perfectly general, 

 and then by basing all further deductions on 

 this one determines rigorously all necessary 

 relations. 



To some teachers it may seem that on this 

 feature of the work too much emphasis is laid, 

 and that too much time, and, possibly, clearness 

 and definiteness are sacrificed to this end. On 

 the other hand, the careful student will main- 

 tain that this one feature should recommend 

 the book most highly, for long after the pupil 

 has forgotten what a cosine is he will have re- 

 tained the habit of mind which distinguishes 

 clearly between the general and the particular, 

 and will be less apt to make that most frequent 

 of all mistakes in logic, that of arguing to the 

 former having proved the latter. Certainly, if 

 the present criticism is at all just, enough has 

 been said to put in evidence the fact that Pro- 

 fessor Miller has succeeded, at important points, 

 in improving Lock's trigonometry, and his 

 work will assuredly be found acceptable to 

 many educators. 



So far as the publishers are concerned, the 

 typographic results are excellent ; different 

 types have been employed with useful discrimi- 

 nation, and a cheerful appearance is given 

 through liberal use of space. The book, how- 

 ever, is, for practical use, large. It contains 

 two hundred pages, is heavier than Chauvenet, 

 while containing only one-fourth as much sub- 

 ject-matter, and three times as heavy as Wells, 

 while, save for some sixty pages devoted to 

 logarithmic tables of questionable value, it does 

 not contain any more. The student of Lock's 

 text book in its present dress will certainly 

 receive the impression that trigonometry is a 

 very large subject indeed, and, the probabilities 

 are that he will never entirely recover from 

 this, his first impression. 



J. B. Chittenden. 

 Columbia TJniveesity. 



SCIENTIFIC JOURNALS. 



THE ASTEOPHYSICAL JOURNAL, MARCH. 



Resume of Solar Observations Made at the Royal 

 Observatory of the Roman College During the Sec- 

 ond Half of 1896 : By P. Tacchini. A general 

 summary of solar observations, giving the dis- 



tribution in latitude of spots, faculse and promi- 

 nences during the period indicated. 



Oxygen in the Sun : By Arthur Schuster. 

 In a short note Professor Schuster calls atten- 

 tion to the close agreement in wave-length be- 

 tween two of the triplets of the ' compound line 

 spectrum ' of the oxygen and two of Young's 

 chromosphere lines. In view of the recent 

 opening of the question of the existence of oxy- 

 gen in the solar atmosphere, Professor Schuster 

 suggests that an accurate determination of the 

 chromorpheric lines in question be made. 



The Yerkes Observatory of the University of Chi- 

 cago — I. Selection of the Site : By George E. 

 Hale. The writer gives a review of the con- 

 siderations that led to the selection of the 

 site of the Yerkes Observatory. A general 

 discussion of the points to be considered 

 in the selection of an observatory site is fol- 

 lowed by a discussion of the conditions to be 

 met in the case in hand. 



Preliminary Table of Solar Spectrum Wave- 

 lengths ; By Henry A. Rowland. 



On the Occurrence of Vanadium in Scandina- 

 vian Rutile: By B. Hasselberg. The paper 

 describes the detection of the heretofore unsus- 

 pected existence of Vanadium in Norwegian 

 and Swedish Rutile. The research was entirely 

 spectroscopic. 



A New Formula for the Wave-lengths of Spec- 

 tral Lines : By J. J. Balmer. The author dis- 

 cusses a generalization of his formula for the 

 hydrogen spectrum. This formula, which is 

 generally known under the name of ' Balmer's 



law,' is 1„ = 3645.6 



«2 — 4 



By introducing a new 



constant c, we have A„ = o 



_ {n + cY 



which is 



{n + c) ^—6' 



found to satisfy the series of lines hitherto in- 

 vestigated by Kayser and Runge by the aid of 

 1 B C 



the formula 



=A—-^—- 



Balmer's new 



law is similar to that due to Rydberg, except 



b 



that the latter considered the value of 



to 



be constant for all elements. Several geomet- 

 rical constructions based upon the formulse are 

 given. 



Minor Contributions and Notes, Reviews of 

 Recent Astrophysical Literature. 



Bibliography of Recent Astrophysical Literature. 



