452 



NATURE 



[August 7, 19 19 



problem. A short note on the equations of similarity 

 as applied to aerial propellers is also unsatisfactory, 

 and indicates a lack of appreciation of the true meaning 

 of the principle of dynamic similarity. Thus, while the 

 general articles are good, the technical section leaves 

 something to be desired, and we hope that in future 

 issues it will more nearly approach the standard 

 of the rest of the production. The quality of paper 

 and letterpress is excellent, but the price of 

 3.50 francs per copy seems rather high for a publica- 

 tion of this kind, however well produced. 



In a paper published recently in the Philosophical 

 Transactions (vol. ccxviii., A, p. 395), Dr. A. E. H, 

 Tutton gives a further instalment towards the com- 

 pletion of that colossal task to the accomplishment of 

 which he has devoted himself through so many years, 

 viz. the complete crystallographic and physical in- 

 vestigation of the sulphates and selenates of the series 



In the investigation of the double ferrous selenates of 

 the alkalis with which this paper deals, special diffi- 

 culties were encountered owing to the unstable nature, 

 first, of the solution of ferrous selenate and, secondly, 

 of the crystals of potassium ferrous selenate which 

 decompose and become opaque within a few hours of 

 their formation. The first' difficulty was overcome 

 by the method of preparation of the ferrous selenate 

 by the action of selenic acid upon ferrous sulphide, 

 and the second by preparing and investigating the 

 crystals of the potassium salt in the depth of winter. 

 The results of the investigation are in complete accord- 

 ance with those previously obtained in the case of 

 other members of the series, and show the regular 

 progression of crystallographic and optical properties 

 with the increase in atomic number (or weight) of 

 the alkalis, and also the almost perfect isostructure 

 of the ammonium and rubidium salts. 



Prof. G. H. Bryan's "Tables of Bordered Anti- 

 logarithms, Trigonometrical Logarithms to every Two 

 Minutes, Natural Functions on Three Pages, Tables 

 of Exact Squares," which occupy twenty pages of the 

 May issue of the Mathematical. Gazette, present cer- 

 tain novelties which will commend their use to cal- 

 culators. The antilogarithms are given to five signi- 

 ficant figures up to tne antilogaritnm of o-6i, there- 

 after to four figures. This increases the accuracy in 

 the lower figures, whether used directly as an anti- 

 logarithmic table or inversely as a logarithmic table. 

 The logarithms of the circular functions are given 

 to every minute from 0° to 5° and from 85° to 90°, 

 and to every two minutes from 5° to 85°. 

 The saving of space by reading up the page 

 for angles between 45° and 90°, although satis- 

 factory for the practised calculator, is not regarded 

 favourably by the school teacher. The table of squares 

 is to five significant figures for numbers lower than 

 316, and to six significant figures for higher numbers. 

 The chief advantage is that the complete square is 

 given for every integral number up to 999. The 

 square of a number of four digits is obtained by use 

 of the formula (N -!-«)' = N'+(2N+s;)x. This is a 

 disadvantage in rapid work. For true accuracy 

 Barlow's tables are all-essential; for limited accuracy 

 to four figures (a very useful thing in laboratory work) 

 the table in Chambers's " Four-figure Tables " would 

 probably be found more serviceable. There is not the 

 least doubt, however, that Prof. Bryan has provided 

 us with a convenient compact set of logarithmic 

 tables of greater accuracy than any similar set which 

 has hitherto been devised. For many important kinds 

 of practical work it is amply sufficient. [ 



NO. 2597, VOL. 103] 



I From an article in the Engineer of July iS we 

 I extract the information that ttie Mitta Mitta Dam 

 ' on the Murray River, the boundary between Victoria 

 and New South 'Wales, Australia, will have a total 

 length of 3601 ft., divided into three sections : — (a) An 

 earthen dam of 2700 ft. ; (b) a concrete spillway 740 ft. 

 long, including turbine wells.; and (c) outlet works, 

 j 161 ft. long. The object of the dam is to effect the 

 storage of 1,000,000 acre-ft., or 272,250 million gallons, 

 of water, so as to secure a regulated flow of 240,000 

 acre-ft. per month for irrigation during the dry 

 season. For this purpose a height of 94 ft. from 

 the bed of the river to full supply level will be re- 

 quired. The earthwork, with a core of concrete, is 

 on the Victorian side of the river, the site-formation 

 being alluvial, overlying beds of sand and gravel, 

 below which there is a layer of decomposed granite 

 of varying thickness. The bedrock of grey granite 

 is reached at a depth of 34 ft. below surface-level, 

 and the dam summit is 85 ft. above the same datum, 

 the level of the crest being such as to give a margin 

 of 12 ft. above full supply level. The spillway lies 

 across the bed of the river, and will be constructed 

 entirely in concrete. The cost of the scheme, includ- 

 ing contingent works, with a series of locks and 

 weirs from Echuca, in Victoria, to Blanchtown, in 

 South Australia, is estimated at 4,5oo,oooL. and is 

 being met by the States of Victoria, New South Wales, 

 and South Australia, and the Commonwealth. 



The Scientific Instrument, Glassware, and Potash 

 Production Branch of the Board of Trade has been 

 transferred from 117 Piccadillv to 7 Seamore Place, 

 W.I. 



A LONG list of second-hand microscopes, spectro- 

 scopes, telescopes, a'nd other instruments and acces- 

 sories has been issued by the firm of Mr. John 

 Browning, 146 Strand, W.Ci2. Copies can be obtained 

 upon application. 



We are asked to announce that Messrs. C. F. 

 Casella and Co., Ltd., have removed their factory 

 from Walworth to Walthamstow, and opened offices 

 and showrooms at 49 and 50 Parliament Street, 

 S.W.I, to which address all correspondence for the 

 firm should be sent. 



The University of Chicago Press has in pre- 

 paration for appearance in the University of 

 Chicago Nature-Study Series "A Field and Labora- 

 tory Guide in Physical Nature-Study" and "A 

 Source Book of Physical Nature-Study." A book 

 of current interest is promised by Messrs. J. M. 

 Dent and Sons, Ltd., for the autumn, viz.. one 

 dealing with the British coal industry. It will be 

 the work of Mr. G. Stone, the assistant secretary to 

 the Coal Commission, who is treating the subject from 

 the historical point of view and that of present-day 

 needs. In the latest list of Messrs. Longmans and 

 Co. we notice '"The Natural History of South Africa," 

 F. W. Fitzsimons, 4 vols., two of which are in the 

 press, viz. vol. i.. Mammals, including the Vervet 

 Monkeys, Baboons, Galagos, Fruit Bats, Insectivorous 

 Bats, Lions, Leopards, Serval Cats, Black-footed 

 Cats, African Wild Cats, Caracals, and Hunting 

 Leopards; vol. ii.. Mammals, including Civets, 

 Genets, Mungooses, Meerkats, Earth Wolves, Hyenas, 

 Jackals, Foxes, Wild Dogs, Otters, Honey Ratels^ Mui- 

 shonds, and Sea Lions ; " Mensuration for Marine and 

 Mechanical Engineers (Second and First Class Board 

 of Trade Examinations)," J. W. Angles ; and a new 

 and abridged edition of " Human Personality and its 

 Survival of Bodily Death," the late F. W. H. Myers, 

 with a portrait and biographical sketch of the author. 



