November 6, 1902] 



NA TURE 



for its subsequent erection. The whole work of erection 

 was successfully completed in three weeks. 



The A. E.G. alternator was not in actual operation at 

 Paris, but was rotated for exhibition purposes by a small 

 motor. An equally large generating set was exhibited by 

 the Helios Company, driven by a triple-expansion engine 

 and used for the lighting of the exhibition. This machine 

 was of special design, as the makers desired to satisfy 

 the requirements of the exhibition authorities and also to 

 make the alternator suitable for subsequent disposal for 

 other purposes. Another alternator of special interest 

 was that exhibited by the Societe l'Eclairage Electrique, 

 which generated at 30,000 volts. This was designed 

 more as an experimental machine, to show the possibility 

 of directly generating at very high pressure and so dis- 

 pensing with step-up transformers. The alternator had 

 only an output of 180 k.v.-a. It is interesting in this con- 

 nection to recall that last February Messrs. Schuchert 

 and Co. completed three 1500 kw. three-phase alternators 

 generating at 20,000 volts, for supplying power to the 

 Valtellina Railway. 



M. Guilbert has collected together all the chief data 

 of the various machines in ten tables as an appendix at 

 the end of the book. There is also given as an appendix 

 a series of twenty oscillograph curves showing the poten- 

 tial wave-forms of a number of the alternators. These, 

 which were taken by means of M. Blondel's oscillo- 

 graph, though very interesting, are hardly accompanied 

 by sufficient data to make them of great value. A casual 

 inspection is, however, sufficient to show that, as M. 

 Guilbert remarks, much progress remains to be made in 

 the construction of alternators before a practically sinu- 

 soidal potential-curve is obtained. Yet though much 

 remains to be done, much has already been accomplished, 

 and the manufacturer of the modern dynamo has nothing 

 of which to be ashamed. His machines are efficient, and 

 he has shown that he is capable of making them of a 

 size suitable to the ever-increasing requirements, and 

 there can be little doubt that when the time arrives he 

 will be able to meet still greater demands. It is not 

 likely to be long before these are made, especially for 

 generators for traction work. But a year or two ago the 

 Westinghouse Company built two 2700 kw. generators 

 for the Boston Elevated Railway ; one is inclined to ask 

 what the size of the units will be when, say, the London 

 and North-Western or the Canadian Pacific Railway is 

 run electrically. We can only hope that it will not be 

 long before an answer has to be given to his question ; 

 that our progress in the future will be as rapid and as 

 sound as it has been in the past ; and that the next 

 seventy years will be as full of development and improve- 

 ment as have been the seventy which have passed since 

 Faraday "did not despair of being able to construct a 

 new electrical machine." M. S. 



OUR BOOK SHELF. 



Thirteenth Annual Report of the Local Governme?it 



Board, 1900-1. Supplement containing the Report of 



the Medical Officer for 1900-1. (London: Eyre and 



Spottiswoode, 1902.) 



The scientific memoirs contained in this volume are of 



considerable interest. Drs. Klein and Houston have 



investigated the behaviour of pathogenic organisms 



NO. 1723, VOL. 67] 



when inoculated upon various farinaceous media, and 

 conclude that the likelihood of infection of the human 

 subject from such source is probably remote. A number 

 of food-stuffs were similarly examined by Dr. Klein for 

 the presence of pathogenic organisms, with the result 

 that none was found. Dr. Gordon has continued his 

 studies upon the bacteriology of scarlatina, and he adduces 

 further proof that the Streptococcus scarlalinae is a species 

 distinct from other streptococci and that it may be the 

 causative organism of this disease. Two papers are 

 concerned with the behaviour of micro-organisms when 

 inoculated into the soil. In the first, Dr. Houston 

 inoculated soil with crude sewage, and found that on the 

 whole the soil-microbes ousted the sewage ones and 

 that the addition of sewage to soil resulted in a temporary 

 increase only of the sewage microbes. In the second, 

 Dr. Sidney Martin has continued his work upon the 

 nature of the antagonism of the soil to the typhoid 

 bacillus ; this organism survives but a short time in the 

 soil, being destroyed by the products of the putrefactive 

 bacteria which exist therein. Dr. Klein also reports on 

 the infection of cockles and mussels with the typhoid 

 and cholera microbes, and shows that these organisms 

 may persist in the interior of the molluscs for some time 

 after the source of infection has been removed. The 

 importance of rats in the dissemination of plague has 

 induced Dr. Haldane to devise an apparatus for gener- 

 ating carbonic oxide gas for destroying these pests in 

 plague-infected ships. This is described and some expe- 

 riments with it are detailed. There is also an interesting 

 report upon research work in connection with glycerinated 

 vaccine lymph. The volume concludes with a number 

 of well- executed photographs illustrating the various 

 papers. R. T. Hewlett. 



The Flora of the East Riding of Yorkshire. By J. F. 



Robinson. Pp. vii + 253. (London: A. Brown and 



Sons.) Price 7s. 6d. 

 THE " Flora of the North Riding of Yorkshire," compiled 

 by Mr. J. G. Baker so long ago as 1S63, furnishes a 

 delightful account of the plants and the plant-associa- 

 tions of that division. Dr. F. A. Lees is responsible for 

 a " Flora of the West Riding" which is equally successful. 

 The present work, therefore, fills up an important gap 

 and completes the botanical survey of the county. The 

 enumeration of plants is preceded by a historical review 

 of earlier compilations and a series of sketches referring 

 to the physiography, meteorology and plant distribution 

 of the district. These, taken in combination with the 

 geological map, add greatly to the interest of the book. 

 At the same time, these chapters seem capable of some 

 improvement. The physiographical chapter brings out 

 very clearly the interesting features of the division, the 

 ancient lake-area now represented by a single lake and 

 patches of marsh in the plain of Holderness, the estuary 

 of the Humber, the Cretaceous formation of the Wolds 

 and the mixed character of the deposits in Derwent-land. 

 But the ecological chapter suffers by being too con- 

 densed, and "xerophiles," " pelophiles," "arenophiles " 

 are tumbling over one another. The contrast of "xero- 

 philes" and " pelophiles ' : on pp. 35, 39, represents a 

 confusion of terms. A more detailed and localised 

 account of the plant forms on the different alluvial 

 deposits and an extension of the very brief indication of 

 successive littoral colonies, as well as fuller descriptions 

 of other local formations, might well be given, and the 

 extra space could be more than gained by a less generous 

 use of type and spacing in the flora proper. In the 

 enumeration of plants, the author and his colleagues have 

 endeavoured to sift out the aliens which are especially 

 abundant round Hull Docks, and also the recorded 

 localities have received personal confirmation as far as 

 possible. The author and the Hull Scientific and Field 

 Naturalists' Club deserve the thanks of botanists for a 



