200 



NA TURE 



[December 28, 1905 



the Panama Canal," in which four locks on each 

 slope would lead to a summit-level 130 feet above sea- 

 level ; and so by greatly reducing the excavation re- 

 quired in the Culebra cutting, the designer considers 

 that the canal could be completed in four and a half 

 years; and it is proposed that a very wide earthen 

 darn should be formed at Bohio with materials 

 dredged in excavating the canal, and conveyed through 

 pipes in the site, thereby creating Lake Bohio, as 

 shown on the plan. Another lake would be formed by 

 a dam .11 Gamboa, outside the line of the canal; and 

 this canal with locks is to be transformed into .1 sea- 

 level canal, when required, entirely by dredging with- 

 out impeding navigation, the dredgers being worked 

 electrically by means of the water-power from the 

 lake, the basin of which is to serve as a depositing 

 ground for the dredged materials. 



Admiral Chester, as an old naval officer, is naturally 

 in favour of a sea-level canal, and supports his view- 

 by numerous extracts from the report of the Engineer- 

 ing Committee ; w-hereas General Abbot, with his wide 

 hydraulic experience, and the International Isthmian 

 Canal Commission of 1899-1901 have advocated the 

 construction of a canal with locks. In face of this 

 conflict of opinion, it is natural that the United States 

 Government referred the technical question last sum- 

 mer to an International Engineering Advisory Board, 

 which recently visited the site; but, according to some 

 newspaper correspondents, the members of this com- 

 mission returned to Washington with discouraging 

 and discordant views, so that their approaching report 

 to the President will be awaited with much interest. 



Undoubtedly, the conditions affecting the choice 

 between a canal with locks and a sea-level canal have 

 been modified by the United States Government hav- 

 ing undertaken the construction of the canal, for the 

 capital cost, which is a most important question for a 

 private company, is of much less consequence to a 

 Government, provided very material advantages, 

 either as to facilities of navigation or a diminution in 

 the expenses of maintenance, can be secured bv a 

 larger initial outlay; and, within certain limits, a 

 prolongation of the period of construction is also of 

 less vital importance. Too much stress, however, 

 appears to have been laid in the report of the 

 Engineering Committee of this year on the restriction 

 offered by locks to navigation and increase in the size 

 ■of ships, and too little account taken of the cost of 

 ■enlarging a canai through an exceptionally deep cut- 

 ting; and also probably much too sanguine a view- 

 is entertained of the period required for the large 

 additional quantity of excavation necessitated bv a 

 sea-level canal, especially considering the uncertain- 

 ties as to the supply of labour. 



The only restrictions to navigation caused by a 

 canal with locks are the time occupied in passing 

 through them, and the possibility of vessels being 

 built larger than they could accommodate; but the 

 loss of time can be considerablv reduced by suitable 

 arrangements for tilling and emptying the locks, 

 their capacity for traffic can be readily increased by 

 ■duplicating them when required, and their dimen- 

 sions would naturally be made at the outset, like the 

 tidal locks at Miraflores, adequate for any probable 

 increase in the size of the vessels. Moreover, in the 

 design shown on the plan, a great portion, if not the 

 whole, of the time expended in locking would be re- 

 couped by the increased speed attained by vessels in 

 traversing the thirteen miles of lake navigation. The 

 advantage of facility of enlargement claimed for a 

 sea-level canal really more rightly belongs to a canal 

 with locks, provided the locks are constructed with 

 due foresight of future requirements; for whereas the 

 portions of the canal from the Atlantic to Bohio, and 

 NO. 1887, VOL. 73] 



from the Pacific to Miraflores, with a total length of 

 25.5 miles, are the same in both schemes, owing to 

 th excavation already accomplished, as shown by 

 shading on the longitudinal section, about 11 miles of 

 the lake portion in the canal with locks are consider- 

 ably lower than required for giving 35 feet draught 

 of water; whilst the remaining \o\ miles of the 

 summit-level of the canal with locks could be enlarged 

 and deepened by 8j feet less depth of excavation 

 throughout than would be necessary for the 

 canal (Fig. 3). 



The only serious objection that has been raised 

 against the design shown in the illustrations is that 

 1 lie proposed dam near Bohio would have to be 

 carried down 42 feet lower to reach a foundation of 

 rock than was anticipated ; but it seems almost in- 

 credible that the commissions appointed during the 

 period that the New Panama Company had control of 

 the works, the special mission of which it was to deter- 

 mine the feasibility and best means of completing the 

 canal, should have neglei led such an importanl in- 

 vestigation a- the foundations for the Bohio dam. 

 'flie statements that the Engineering Committee, in 

 its report of this year, had presented the first definite 

 plan for the construction of the canal, and that the 

 \ini rican engineers bad discovered a better site for a 

 dam at Gamboa, which formed part of the original 

 si hi me, seem to indicate a bias against previous 

 schemes, and a desire to appear to strike out a novel 

 line. So far as information is at present available, 

 and assuming that the Bohio dam can be executed as 

 designed, it appears that a canal with locks would 

 cosl much less, be much sooner completed, and 

 would be much more easily and cheaply enlarged than 

 a sea-level canal, and that the greater facilities for 

 navigation which might possibly be afforded by the 

 larger scheme would, owing to the lake navigation 

 offered bv the other, be so insignificant as not to 

 justifv the additional cost, delays, and uncertainties 

 the construction of a sea-level canal would entail. 



Since the above article was written, the Advisory 

 Board of Engineers has by a majority of three re- 

 commended the construction of a sea-level canal, 

 three American and five foreigners voting in favour 

 of it, and five Americans against, giving the prefer- 

 ence to a canal with locks ; but the report of the 

 Board has not vet been published. 



THE BIOMETRICS OF BRAIN-WEIGHTS. 



" We are not endeavouring to discredit anthropology, but to furnish such 

 branches of it as anthropometry and craniology with new tools — a little 

 sharp-edged to the uninitiated who handle them incautiously— but which 

 will raise anthropometry and craniology in the future into the category ot 

 the more exact sciences" (Karl Pearson. Biometrika, vol. iii., p. 153, 

 1904). 



" There is a mathematical science of statistics which must be learnt, and 

 papers dealing numerically with anthropometric and cran : ometric data 

 which do not now apply this theory are dimply outside the field of science " 

 (Biometrikat vi.il. iii., p. 397, 1904). 



IT is not a raid, but a victorious invasion, that Prof. 

 Karl Pearson and his school have made into the 

 realms of anthropology, with the result that all that 

 part of it which deals with men in the mass becomes 

 an annex of the mathematician. The invasion 

 occurred at a most opportune time; great collections 

 of data which had been accumulated by the anthro- 

 pologist threatened to bury him, for he had neither 

 the method nor the appliances for welding them into 

 a composite whole. Especially was this the case with 

 the endless measurements of brain-weights obtained 

 most laboriously bv the anatomist and pathologist; 

 they urgently required an application of the " mathe- 

 matical science of statistics." Hence the series of 

 articles which occupy the greater part of a number of 



