October 30, 1919] 



NATURE 



171 



MINERAL RESOURCES OF GEORGIA. 



Mineral Resources of Georgia and Caucasia: 

 Manganese Industry of Georgia. By D. Gham- 

 bashidze. Pp. 182. (London : Georgfe Allen 

 and Unwin, Ltd. ; New York : The Macmillan 

 Co., 1919.) Price 8s. 6d. net. 

 'T'HIS little book is interesting as being the out- 

 -*- come of the reorganisation of national boun- 

 daries after the war and as evidence of the poli- 

 tical and economic independence of the new Re- 

 public of Georgia ; this was an independent king- 

 dom until it was forcibly annexed by Russia in 

 1801, and only recommenced its autonomous exist- 

 ence in 1917. The object of the work now pub- 

 lished by Mr. Ghambashidze is to make British 

 readers acquainted with the industrial importance 

 of Georgia and Caucasia so far as the mineral 

 wealth of this region is concerned. The author 

 gives a long list of the various mineral substances 

 of economic value known to occur therein, 

 although relatively few have been worked on an 

 industrial scale. 



The oilfields of Caucasia have long been 

 known, the principal field, that of Baku, 

 having been for many years one of the 

 world's great producers, with an annual 

 (pre-war) output of about 7 million tons of 

 petroleum. Next in importance comes that of 

 Grozny, with a production of i-ij million tons, 

 and there are also several smaller ones, the out- 

 put from which is at present negligible ; even the 

 Maikop field, the first borings in which aroused 

 so much excitement, has sunk to a quite unim- 

 portant factor in the general production. Of the 

 other non-metallic minerals, bitumen is at present 

 the most important, though the sulphur deposits 

 in the province of Erivan, 30 miles from a rail- 

 way hne, may prove to be of value in the near 

 future. 



Of the metallic minerals, a few deposits 

 of iron-ore are known, but none apparently of 

 great importance. There are several known 

 deposits of blende and galena, but only one, a 

 mine at Sadon, is being worked at present; it is 

 in the hands of a Russo-Belgian company, the 

 Societe Minifere et Chimique Alagir. Copper is 

 abundant and has been worked in many parts of 

 (ieorgia and Caucasia. The best known of all is 

 the Kedabek mine at Mis-Dag, which was an 

 important producer up to about 1912, when the 

 deposits began to show signs of exhaustion, so 

 that the present output is barely 100 tons of copper 

 per annum, whereas it was at one time up to 

 1750 tons. Altogether there were in 1914 some 

 twenty-eight copper mines at work, fourteen of 

 which had their own smelters ; the total produc- 

 tion of copper in 1914 was 8259 tons. The most 

 important of the metalliferous minerals is man- 

 ganese ore. In addition to a number of deposits 

 in various parts of Georgia, which are not being 

 worked at present, and are briefly referred to, 

 the well-known deposits in the province of Kutais, 

 which cover an area of 400 square miles and are 

 estimated to contain 200 million tons of available 

 NO. 2609, VOL. 104] 



ore, are described in some detail. The exports 

 of this ore from Georgia had reached more than 

 a million tons in 1913, but then fell off rapidly 

 owing to the war. There appears to be no reason 

 why this industry should not again recover its 

 previous importance. The book contains a valu- 

 able amount of statistical information carefully 

 tabulated, showing the mineral production of the 

 districts treated of, and should be of use to all 

 engaged in the mineral industrv of the Near East. 



H. L. 



OUR BOOKSHELF. 

 A Simple and Rapid Method of Tide Prediction. 

 (Including Diurnal Time and Height Inequali- 

 ties.) By Sgt. M. E. J. Gheury. Pp. 53. 

 (London: J. D. Potter, 1919.) Price 5$. 

 In this little book the author explains the method 

 which he developed for predicting the time and 

 height of high and low water at Richborough, on 

 the River Stour (Kent). From observations of 

 these variables, extending over a fortnight only 

 (in the first instance), it proved possible to deduce 

 satisfactory predictions with but little trouble. 

 The method has a rational basis, which is 

 described in a preliminary account of the tide- 

 producing forces and their variations. The work 

 involved is partly graphical and partly tabular, 

 but no harmonic analyses are required. The aim 

 is to replace the unsatisfactory method by which 

 a set of corrections is applied to the high- and 

 low-water data for the nearest standard port, 

 which at some stations may be as much as 200 

 miles away. In the present case the nearest 

 standard port was only 20 miles away (Dover), 

 but even in this instance Mr. Gheury's method, 

 applied to deduce times of high water, gave better 

 results than did the application of a correction 

 to the elaborately derived Dover data. Rich- 

 borough, being situated several miles up a narrow 

 and sinuous tidal stream opening in a bay, 

 presents some rather complex tidal features, in- 

 cluding well-marked diurnal height and time in- 

 equalities; the success of the method, which can 

 readily be applied to other similar or simpler 

 stations, is therefore the more significant. The 

 book is marred by some irritating misprints and 

 grammatical errors, but the explanations are, on 

 the whole, correct and lucid. 



Fermat's Last Theorem: Three Proofs by Ele- 

 mentary Algebra. By M. Cashmore. Revised 

 edition. Pp. 55. (London : G. Bell and Sons, 

 Ltd., 1918.) Price 2s. 6d. net. 

 It is unfortunate that F. P. Wolfkehl's legacy of 

 a prize for settling the vexed question of 

 " Fermat's Last Theorem " should have stimulated 

 such a large erroneous mathematical literature. 

 Most of the publications pretending to prove the 

 theorem are deplorable for at least three reasons : 

 first, because many of their authors have had in- 

 sufficient mathematical training to enable them 

 to decide whether a supposed proof is sound or 

 not; secondly, because ctf the expense incurrc'f 

 by the authors in printing invalid proofs; ani 



