148 Notices respecting New Boohs. 



of thirty carefully prepared maps of the principal Star Groups, and 

 accompanying each one, on the opposite page, a short description 

 is given of the most interesting objects. We should have liked 

 to see these descriptions more complete, as there is considerable 

 blank space left, and Mr. Gore is so much at home amongst stellar 

 objects that he might readily have utilized it with further valuable 

 references. The maps will prove of great utility to everyone who 

 employs them as a means of becoming acquainted with the con- 

 figuration of the leading Star Groups. Mr. Grore mentions in his 

 preface that his "little maps are intended as an aid to the 

 beginner," and this intention will doubtless be realized in many 

 cases ; but we hope the student will not feel nonplussed by the 

 opening paragraph accompanying Map xiii., where it is stated : 

 " Aries, the Earn, is the first sign of the Zodiac, or that in which 

 the Vernal equinoctial point was situated in the time of Hip- 

 parchus. Owing, however, to the precession of the equinoxes this 

 point has now retrograded into Pisces." Of course this reads 

 simple enough to those well versed in the subject, but it is likely 

 to prove too technical for mere beginners. On the whole, how- 

 ever, Mr. G-ore's book undoubtedly merits commendation. Many 

 a tyro can spend an agreeable hour in comparing the charts with 

 the stars seen in the heavens and identifying the various groups as 

 well as their individual stars. The volume is an example of Mr. 

 G-ore's well-known accuracy. We hope that, if a second edition is 

 called for, the author will iu elude one or two maps of Draco, a 

 constellation which abounds in bright stars and which, large and 

 straggling though it is, contains many interesting objects always 

 visible in our latitude. The conspicuous stars in the head of 

 Draco may be said to form a constellation by themselves ; then 

 there are £, n, 0, and i, which make up another bright group ; a 

 third attracts the eye near B ; and <j>, ^, and \p form a pretty tri- 

 angle about 5° N". of the pole of the ecliptic. 



An Elementary Treatise on the Integral Calculus, containing Ap- 

 plications to Plane Curves and Surfaces, and also a Chapter on 

 the Calculus of Variations, ivith numerous Examples. By 

 B. Williamson, D. 8c. 9 F.R.S. London: Longmans, 1891 

 (pp. xvi+463). 



The fact that this is the Sixth edition shows most unmistakably 

 that Dr. Williamson has met the wants of students of the ' Calculus.' 

 In the April No., 1881, we noticed the third edition. We have 

 before us the first edition (a very modest volume), 1875 (pp. vi + 

 267) ; the second edition, 1877 (pp. xi+348); the third edition, 

 1880 (pp. xiv + 375). The issue of Six editions of a Mathematical 

 treatise in sixteen years must be almost, if not quite, unprecedented. 

 It is evident from the data above enumerated that the author is not 

 content to rest upon his oars, but has laboured to make each edition 

 better than its predecessor. A particular examination of so 

 familiar a text-book is not called for here, and we shall simply 



