472 SCIENCE PROGRESS 



The Transition Spiral, and its Introduction to Railway Curves, with Field 

 Exercises in Construction and Alignment. By Arthur Lovat 

 HiGGiNS, M.Sc. A.R.C.S., A.M.Inst.C.E. [Pp. viii + iii, with lo 

 illustrations.] (London : Constable & Co., Ltd., 1921. Price 6s. net.) 



In this book the various formulae used in laying out a transition curve are 

 collected and amplified, with special reference to the curve known as Glover's 

 Spiral. 



After a general account of the formulae, there are a set of worked examples 

 which should prove useful to the practical man, and the close agreement be- 

 tween the cubic parabola and the Glover's Spiral is pointed out. It may be 

 thought unfortunate that the term " deflection angles " has been used in 

 places for what might better be called " tangential angles" ; but Mr. Higgins 

 can at least argue that if this is a fault it is by no means singular to his book. 



M. T. M. O. 



ASTRONOMY 



The Elements of Theoretical and Descriptive Astronomy. By Charles T. 

 White, A. M., formerly Professor of Mathematics of Harvard College. 

 Eighth Edition. Revised by Paul P. Blackburn, Commander U.S. 

 Navy. [Pp. xi + 309, with 84 figures and 9 plates.] (New York: John 

 Wiley & Sons. London: Chapman & Hall, 1920. Price 175. 6d. net.) 



This volume is the eighth edition ol a work first published in 1869 to meet 

 the requirements of the United States Naval Academy. At the date of its 

 initial publication it represented fairly the state of astronomical knowledge, 

 and it gave in a simple, concise, and readable treatment the essential facts 

 required by a student taking an elementary course in astronomy. With 

 successive revisions, however, the volume has gradually become hopelessly 

 out of date, and that it has reached an eighth edition is doubtless due to its 

 adoption as a textbook at the U.S. Naval Academy. 



Only a few instances can be given to illustrate the failure to bring the work 

 up to date ; the volume contains many others. Our knowledge of promi- 

 nences is thus summed up : " Mr. Lockyer, of England, who has since examined 

 them, pronounces them to be merely local accumulations of a gaseous envelope 

 completely surrounding the sun." In dealing with solar eclipses, no 

 mention is made of information derived from eclipses later than 1868. The 

 greater part of the section dealing with the solar motion is concerned with 

 the work of Otto Struve and " Mr. Airy." The much more important modern 

 investigations are disposed of in two lines. Star-streaming is not even 

 referred to. The important work of recent years in the determination of 

 radial velocities and of the orbits of spectroscopic binaries is represented by 

 the statement that " Mr. Higgins, using a spectroscope of large dispersive 

 power, and carefully comparing the spectrum of Sirius with that of hydrogen, 

 found that the line F in the spectrum of Sirius was displaced by about ^zsth. 

 of an inch." The only important event since 1891 considered to be worth 

 chronicling in the table of astronomical chronology is the completion of the 

 Cape Photographic Durchmusterung. 



These instances will sufiice to illustrate the success of the reviser. It is 

 not probable that the volume will find much sale outside the Academy for 

 which it was originally written. H. S. J. 



The Parallaxes 0! 260 Stars derived from Photographs. By S. A. Mitchell 

 assisted by C. P. Olivier, H. L. Alden and others. Publications of 

 the Leander McCormick Observatory, Vol III. [Pp. 659]. (New 

 York: Columbia University Press, 1920.) 



This publication contains the detailed results of the parallax determinations 

 of a first series of 260 stars derived at the Leander McCormick Observatory. 



