394 



NATURE 



[August 24, 1905 



exercises in the use of symbols to the difficult problems 

 in surds, theory of exponents, quadratics, and in arith- 

 metical and geometrical progressions. The work 

 shows no trace of having been influenced by the 

 reform movement going on in this country, but 

 teachers will receive valuable hints and much useful 

 matter by consulting this thorough and extensive 

 compilation. 



The " Geometrical Conies " by Messrs. Caunt and 

 Jcssop is a preliminary deductive course for students 

 about to enter on a systematic study of analytical 

 geometry. Only the leading properties of conies are 

 dealt with, and these are established when possible 

 from corresponding properties of the circle by the aid 

 of the modern methods of projection. The book is 

 well suited to its purpose. 



VA^AMA r.LY,4L. 

 Problems of the Panama Canal. By Brig.-General 

 Henry L. Abbot, U.S. .'^rmy. Pp. xi + 248. (New 

 York: The M.-icmlllan Company; London: Mac- 

 millan and Co., Ltd., 1905.) Price 6s. 6d. net. 

 I ^HE author of this book acquired distinction in 

 -*- hydraulics in early life by the publication, in 

 conjunction with Captain Humphrej's, of their well- 

 l<no\vn " Report on the Physics and Hydraulics of the 

 Mississippi River " in 1861 ; and, accordingly, this 

 statement of the problems of the Panama Canal, in 

 which hydr.-uilics are so largely involved, by such a 

 high authority, who, as a member of the technical 

 committee of the New Panama Company, devoted 

 seven years to their study, deserves the most careful 

 consideration of the American nation, for whose guid- 

 ance this volume has been published. It appears at a 

 very opportune time, when the LInited States Govern- 

 ment has undertaken the completion of the works, but 

 has entrusted to a commission of engineers the con- 

 sideration of the precise designs for the canal. 



The chapters on the "New Panama Company," 

 with uiikh the .-luthor was connected, " The Rival 

 Routes " of P;m:uiia and Nicaragua, the " Physical 

 Conditions of the Isthmus," "The Chagres River," 

 with its torrential floods and difficulty of control, and 

 the " Disposal of Rainfall," all present features of 

 interest, and the last three are essential in a study 

 of the works to be carried out ; but undoubtedly the 

 most interesting portion of the book for the British 

 public and engineers generally is contained in the 

 final chapter on " Projects for the Canal." It will be 

 remembered that when M. de Lesseps started the 

 scheme about twenty-five years ago he proposed the 

 construction of a tide-level canal ; and the works were 

 commenced on this basis with very inadequate in- 

 vestigations of the nature of the strata to be traversed 

 by the cuttings, especially- through the Culebra ridge, 

 and the physical conditions of the locality. When ex- 

 perience had proved the unexpected magnitude of the 

 undertaking, and the unforeseen difficulties to be over- 

 come, the original company, approaching the end of 

 its resources, decided in 7887 to introduce locks, 

 thereby greatly reducing the amount of excavation, 

 NO. 1869, VOL. 72] 



and also the time required for the completion of the 

 canal. Eventually, after the failure of the first 

 company, a New Panama Company was formed in 

 1894 (given by a misprint as 1904 in the introduction); 

 and the works for a canal with locks were slowly pro- 

 ceeded with as funds permitted, until at length, last 

 vear, the United States Government purchased the 

 undertaking with the view of carrying it out as a 

 national work. Early this year an engineering com- 

 mittee of the Panama Commission recommended a 

 sea-level canal again, with a bottom-width of 150 feet 

 and a minimum depth of 35 feet, and the necessary 

 duplicate tidal locks near the Panama end, capable of 

 accommodating vessels up to 1000 feet in length and 

 100 feet in width. 



The principal objections to the formation of a canal 

 across the isthmus at sea-level throughout, are the 

 time, difficulties, and cost involved in making a 

 cutting, reaching a depth of 317 feet, in unfavour- 

 able strata exposed to tropical rains, and the efficient 

 control of the River Chagres, which crosses the line of 

 the canal on the .Atlantic slope in several places, and 

 the floods of which will become a more serious peril to 

 the maintenance of the canal in proportion as the 

 water-level of the canal is lowered. The objection of 

 cost, and, to some extent, that of time, are of con- 

 siderably less importance in a national than in a 

 private undertaking; but tlie floods of the Chagres 

 appear liable to prove a standing menace to the safety 

 of a tide-level canal. The Isthmian Canal (Commis- 

 sion of 1899-1901 expressed its disapproval of a sea- 

 level project in the following words : — 



" The cost of such a canal, Including a dam at .Mha- 

 juela, and a tide lock at Mlraflores near the Pacific 

 end, is estimated at not less than 240,000,000 dollars. 

 Its construction would probably take at least twenty 

 years. This Commission concurs with the various 

 French Commissions which have preceded it, since 

 the failure of the Old Company, in rejecting the se.i- 

 level plan. While such a plan would be physically 

 practicable, and might be adopted if no other solution 

 were available, the difficulties of all kinds, and espeii- 

 ally those of time and cost, would be so great that 

 a canal with a summit level reached by locks is to be 

 preferred." 



The author regards these remaining difiiculties as 

 very important; and, after discussing them, and par- 

 ticularly the problems concerning the control of the 

 Chagres, he concludes his book with the following 

 expression of his opinions : — 



" It is the unanimous opinion of all the engineers 

 who have had practical experience in canal work, and 

 time to thoroughly study the problem, that no sea- 

 level projct without locks, and no sea-level canal 

 even with a tidal lock, is practicable that would be 

 comparable in ease and safety of transit to one 

 equipped with modern locks, and planned to take ad- 

 vantage of all the desirable elements which the natural 

 conditions offer. Why, then, waste an extra ten or 

 a dozen years, and untold millions of dollars, to 

 execute a scheme which the investigations of thirty- 

 five years have demonstrated to possess only a senti- 

 mental merit due to the imagination of M. de Lessejis ? 

 Congress and the .American people are Impatient for 

 the opening of the best possible canal." 



