244 



NATURE 



[July i6, 1896 



tull operation, no restriction being placed on the quantity 

 used, the daily consumption amounted to seventy-eight 

 gallons per head of the whole population, or ninety 

 gallons for each water consumer. 



From time to time the works have had to be enlarged 

 and additional reservoirs built, until in 1875 ■' ^^'•''s 

 determined to build a second aqueduct connected with 

 a new reservoir to hold 1900 millions of gallons. 



The new aqueduct, including a short length of pipe 

 line, is thirty-four miles long, twenty-nine miles of which 

 are in tunnel through gneiss rock. This aqueduct is 

 lined throughout with masonry. The standard shape, 

 where not under pressure, is of horseshoe section with a 

 diameter of fourteen feet, the sectional area being equal 

 to a circular masonry culvert having an internal diameter 

 of fourteen feet. The available head is 3370 feet, which 

 is absorbed in overcoming friction through the conduit 

 and pipes. The grade is at the rate of 07 feet per mile, 

 and the velocity of the flowing water 3'27 feet per second. 

 It is capable of discharging 300 millions of gallons in 

 twenty-four hours. 



The "Cornell" reservoir, now under construction, will 

 contain when completed 32,000 million gallons. The 

 central masonry dam is 600 feet long, with an earthen 

 continuation of the same length. The maximum height 

 of the masonry dam is 260 feet, the height above the 

 river-bed being 159 feet, the top being 10 feet above the 

 water-line. It is to be 18 feet wide at the top, and 

 185 feet at the base. 



The total capacity of the conduits now supplying 

 the city, which has a population at the present time of 

 one and a half millions, is 425 millions of gallons. The 

 total storage capacity of the reservoir is 75,000 millions 

 of gallons, equal to a minimum supply in the driest years 

 of 280 millions of gallons. 



Mr. VVegmann's book is almost entirely of an historical 

 and descriptive character, and is confined entirely to the 

 works carried out for the water supply of New York. 

 The details of these various works are, however, so co- 

 piously illustrated that they give the book an eminently 

 practical character, which renders it of value to any 

 engineer engaged in water-works construction. 



A NEW CHEMICAL DICTIONARY. 



A Dictionary of Chemical Solubilities. Ino7-ganic. By 

 Arthur Messinger Comey, Ph.D. Pp. ,\x -I- 515. 

 (London : Macmillan and Co., Ltd., 1896.) 



THIS is a book about which it is impossible to get up 

 any feeling of enthusiasm ; but one cannot resist a 

 sense of wonder and admiration at the patient, plodding 

 spirit in which the compiler must have set about his 

 weary task, and carried it on through months or years of 

 labour to the dreary end. Of course he is an American. 

 In no other nation of the earth using or abusing the 

 English tongue would a man have been found to under- 

 take such an enterprise ; but why the busy, rushing life of 

 tTiat great country across the Atlantic should breed so 

 many compilers of catalogues and bibliographies and in- 

 de.xes, especially of physical science, of books which 

 Charles Lamlj would have called no books, biblia a-biblia, 

 NO. 1394, VOL. 54] 



it seems hard to say. The world ought to feel grateful to 

 them, but usually it does not. It often uses such cyclo- 

 p;cdias, though ready enough to grumble if it finds them 

 less than perfect. In this volume the only smack of 

 literary flavour is to be found in the preface, wherein the 

 extract from " Peter .Shaw's Chemical Lectures, publickly 

 read at London in 1731 and 1732," shows that the plan 

 of such a book was foreshadowed long before its accom- 

 plishment. For, according to the author, the first work 

 that undertook to carry out the idea in its entirety was 

 produced by Prof. F. H. Storer in 1864. All chemists 

 are familiar with Storer's "First Outlines of a Dictionary 

 of Solubilities of Chemical Substances," though long since 

 out of print. It will at once be noticed that there is an 

 important difference in the titles of the two works. Dr. 

 Comey is, however, justified in using the expression 

 "chemical solubilities," inasmuch as he does not confine 

 his work to data concerning solutions in water and 

 alcohol or other neutral solvents, but includes the action, 

 for example, of acids upon metals, and the effects of 

 various liquids, such as solutions of potash and aqueous 

 acids. Moreover, certain physical facts are mentioned, 

 such as changes of temperature on dilution, also any 

 data obtainable regarding the boiling-points of solu- 

 tions, and tables giving the specific gravities of aqueous 

 solutions. 



After all, the more modest title— " First Outlines" — 

 adopted by Storer, seems to assume quite enough ; for the 

 materials for such a work amount at present to little more 

 than a most miscellaneous collection of more or less in- 

 accurate estimations of solubilities, without any clue 

 as to the cause of solubility, and theories as to the 

 condition of the dissolved substance still in conflict. 

 This, however, has not deterred the compiler, who, on 

 the whole, has done his work carefully and well. It 

 would, 'perhaps, help the users — we can hardly speak of 

 readers — of the Dictionary if in a future edition the general 

 statements were somewhat amplified, and gathered to- 

 gether into an introductory chapter apart from the alpha- 

 betical array of details concerning particular cases. For 

 example, it is obvious in regard to salts that the solubility 

 in water is determined more by the nature of the negative 

 radicle than of the metal. We can say truly that all 

 nitrates are soluble in water except a few basic com- 

 pounds, but we cannot predicate anything general con- 

 cerning the solubility of the compounds, say, of lead. 

 Some of these broad statements are given in the 

 Dictionary, but they might be extended with advantage. 

 A classification of the metals according to the action of 

 water and of acids upon them might be given ; it might 

 also be worth while to state what is known of the colours 

 of dissolved inorganic substances, concerning which there 

 are some very curious facts which probably have an im- 

 portant significance could we only find the clue to their 

 explanation. 



From what has been said, it is obvious that this volume- 

 contains a mass of information brought together from a 

 great variety of sources. It will certainly be found 

 useful not only in the chemical laboratory, but also by the 

 manufacturer and practical man to whom time is mone\-. 

 It may therefore be fairly described as one of those books 

 which no chemist's library should be without. 



