January 8, 1903] 



NA TURE 



22' 



subject will be of much use to machine-tool makers. The 

 book under notice is well worth studying ; it gives an 

 able description of the metallurgy of iron and steel ; it 

 deals with the subject in a concise manner and contains 

 much useful general information. The subject is ap- 

 proached from a scientific point of view, and this is as it 

 should be. Special tool steels are now coming very 

 rapidly to the front ; in fact, " Mushet," so long the sheet 

 anchor of the machine shop, is being displaced by these 

 special steels, which only require hardening in a blast of 

 compressed air, thus getting over the risk of cracks due to 

 water hardening and doing infinitely more work. Machine 

 tools have now to be designed to meet the requirements 

 of these new tool steels, more power being required to 

 take the heavier cuts rendered possible by their use. 

 The volume contains much unusually accurate inform- 

 ation, but in section 72 we read that the piston rod of a 

 steam engine is of " mild steel " ; if a forty-ton steel can 

 be called " mild," then the reviewer is with the author ; 

 the same may be said of material for crank pins. Taken 

 as a whole, we can recommend this book. Students of 

 machine design should study it, and those of metallurgy 

 will not waste their time by doing so. 



LETTERS TO THE EDITOR. 

 [ The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of NATURE. 

 No notice is taken of anonymous communications.} 



Traces of Past Glacial Action in the Orange River 

 Colony, South Africa. 



The subject of glaciation in South Africa is so interesting 

 and important that I venture to take an early opportunity of 

 dire.-ting the attention of geologists to the farm of Brit Koppje, 

 siluited about three miles west of Vredefort Road Station, filty 

 miles north of Kroonstad, in the Orange River Colony. Here, 

 on a koppje, the surface of the rock is so very conspicuously 

 smoothed and rounded that its appearance can hardly, I think, 

 be attributed to the action of any agent other than ice. The 

 general resemblance to photographs of the glaciated rocks at 

 Prieska in Cape Colony recently shown me by Mr. A. W. 

 Rogers, of the Cape Colony Geological Commission, is very 

 great (see a paper read before the South African Philosophical 

 Society by Messrs. Rogers and Schwartz on November 29, 

 1S99). 



• T le bedding planes of the rock are perpendicular and the 

 strike is nearly from north to south. So far as I can recollect 

 (although I was unable to take any accurate observations on this 

 point), they are cut across by the slope of the rounded surfaces, 

 which run rather in a north-easterly to south-westerly direction. 



The locality can be very easily visited from Vredefort Road 

 Station. G. E. II. Barrett-Hamilton. 



Rilmanock House, Arthurstown, Ireland, 

 December 22, 1902. 



Risley's "Tribes of Bengal." 



Having had occasion to make use of Mr. H. H. Risley's 

 valuable anthropometric data of the tribe; and castes of Bengal, 

 som: of the "means" for the cephalic breadth, minimum 

 frontal breadth and maximum bizygomatic breadth were inci- 

 demally recalculated. This was done whenever the tabulated 

 value for the mean seemed a highly improbable one, and as 

 some serious differences between our means and those given by 

 Mr. Risley were found, it was thought well to point this out for 

 the benefit of those who may be basing their arguments on these 

 data without recalculation. Thus, in vol. i., for the Murmi 

 tribe of the Darjiling Hills, for the mean minimum frontal 

 breadth Mr. Risley gives 113-5, where we find 107-2 ; for the 

 maximum bizygomatic breadth Mr. Risley's value is 145-9, 

 ours is 138-4. 



In vol. ii., Kachi caste of N.W. Provinces and Oudh, for the 

 maximum bizygomatic breadth Mr. Risley's value is 120S, 

 ours is 130-0. Pathan caste of Panjab, for the minimum frontal 



breadth Mr. Risley's value is 117-7, ours ' s II0 3- These are 

 very serious differences. 



As it was important to determine how far these discrepancies 

 reflected on the general accuracy of the work, the means for six 

 tribes taken at random were recalculated. I will merely give a 

 list of the figures for the means : — 



RMey. 

 I32-S 

 I43"2 



I02'6 



1325 



i 3 S-6 

 977' 



Recalculntion. 

 '32-57 



H3' 2 5 

 102 60 



■3^59 ' 

 13S69 



9773 



There is substantial agreement, except in the decimal figure. 



S. M. Jacob. 

 Ciometric Laboratory, University College, London, 

 December 21, 1902. 



Local Floras of India. 



The writer of the notice of "The Trees, Shrubs and Woody 

 Climbers of the Bombay Presidency," by W. A. Talbot 

 (Nature, December 18, 1902, p. 14S), refers to the need of 

 local floras to supplement Sir Joseph Hooker's "Flora of British 

 India," and names several works of this nature, though not always 

 correctly, which have already appeared. Perhaps I may be 

 permitted to add a few facts on this subject. 



Inthefirstplace.it should be known that Sir Dietrich Brandis's 

 '■ Forest Flora of the North- West and Central India 'Ms not, in 

 any sense, an outcome of the " Flora of Briiish India," as it was 

 published before the first volume of the latter work. Further, 

 the late Dr. Trimen's " Handbook of the Flora of Ceylon " was 

 not completed by himself, the last two volumes having been 

 prepared by Sir Joseph Hooker. Among the local floras not 

 mentioned by the writer of the notice in question is Dr. T. 

 Cooke's excellent "Flora of the Bombay Presidency" (see 

 Nature, vol. lxv., 1901, p. 88), of which two parts have been 

 issued, containing the natural orders Ranunculaceas to Le- 

 guminosx. Two other important works of the same class aie 

 nearly completed, namely, " The Flora of Bengal " and ' ' The 

 Flora of the Gangetic Plain." The former is by Major D. 

 Prain, the Superintendent of the Calcutta Botanic Garden and 

 Director of the Botanical Survey of India, and the latter by 

 Mr. J. F. Duthie, Director of the Botanical Department, 

 Northern India. I am not sure that I have given the exact 

 titles these two books will bear. Then there is the modest but 

 useful "Forest Flora of the School Circle, N.W.P.," by 

 Upendranath Kanjilal. More ambitious among the works 

 supplementary to the "Flora of British India" are the 

 " Annals of the Royal Botanic Garden, Calcutta," commenced 

 by Sir George King and continued by Major Prain. Upwards 

 of 1600 quarto plates illustrative of the flora of India have 

 appeared in this publication, including 450 orchids. Finally, 

 there is the second edition of Gamble's " Manual of Indian 

 Timbers," which contains a vast deal more information than the 

 title would imply. W. Botting Hemsley. 



Herbarium, Kew. 



It was not necessary for our purpose to cite all the works 

 dealing with the Indian flora that were published during the 

 quarter of a century that elapsed between the issue of the first 

 (1872) and of the last volume of Sir Joseph Hooker's " Flora 

 ofBritishIndia"(lS97). In the preface to vol. vii. of that work, 

 the " Forest Flora of the North-West and Central India," by 

 Dr., now Sir, Dietrich Brandis, is mentioned among the works 

 "that have appeared during the publication of the 'Flora of 

 British India,' " and the date assigned is 1874. 



The first part of Sir Joseph Hooker's " Flora " was issued in 

 May, 1872, the second in January, 1874, the third in February, 

 1875 ; it is in this latter section, at p. 527, that we find the first 

 citations from Dr. Brandis. 



Other publications of Mr. C. B. Clarke, the late Mr. Kurz 

 and Colonel Beddome are alluded to in Sir Joseph Hooker's 

 preface, in addition to those cited in Mr. Hemsley's note. 



The second edition of Mr. Gamble's "Manual of Indian 

 Timbers" has only reached us quite recently, and, as we 

 believe, since our previous note was written. 



The Reviewer. 



NO. 1732, VOL. 67] 



