October 14, 19 15] 



NATURE 



69 



was formerly number of tin- Xaval War College 

 Staff, and the third, Dr. Emery Johnson, is special 

 commissioner on the Traffic and Tolls of the 

 Panama Canal. 



Mr. Bakenhus narrates the history of the pro- 

 ject, and gives a clear account of the design and 

 construction of the canal. His treatment of the 

 phenomena presented by the landslides is, how- 

 ever, inadequate, and not marked by any origin- 

 ality of thought. They still occur at intervals, 

 seriously reducing the depth of the waterway ; it 

 is quite uncertain when they will cease, and until 

 that time comes the canal will not be thoroughly 

 satisfactory as a link in the chain of naval com- 

 munication between the Atlantic and Pacific 

 Oceans. 



Captain Knapp deals with the United States 

 Navy and the Panama Canal, detailing the reduc- 

 tions of sea distance. The strategic aspect of the 

 canal has not received sufficient attention in this 

 country, considering that it was primarily intended 

 for the use of the United States Navy. But if 

 the British public has been in the past somewhat 

 prone to neglect the study of strategy, our con- 

 dition is one of enlightenment compared to the 

 general misapprehension of such matters by 

 American citizens. 



"The United States," says Capt. Knapp, "is 

 not a military nation. There is little considera- 

 tion and less understanding among the people at 

 large of military matters. The Government has 

 no defined military policy, using military in its 

 wide sense, and it has no defined naval policy." 



The plain fact is that the American Govern- 

 ment is gambling on the maintenance of the 

 balance of power in Europe. Once let the balance 

 of forces on our side be destroyed and the Mon- 

 roe doctrine could not be upheld by the naval and 

 military force now at the disposal of the United 

 States, and the whole fabric of American imperial 

 policy would fall. The time which would be re- 

 quired to prepare the United States for war with 

 great Powers is probably under-estimated by 

 most people. The first step must be the education 

 of the people to its necessity, which necessarily 

 takes time. The creation of an adequate staff of 

 trained officers for a large army also takes time; 

 and the building up of a merchant marine, so 

 much required for the navy, is an extremely diffi- 

 cult problem in view of the economic conditions 

 in America. 



If the Government of the United States began 

 to-morrow to prepare for a serious war we do not 

 think that the country would be ready in less than 

 twenty years. It is earnestly to be hoped in the 

 interests of Anglo-Saxon civilisation that the great 

 and patriotic democracy of America will turn its 

 keen intelligence to the study of war. V. C. 



NO. 2.^q8, vol. q6l 



OVR BOOKSHELF. 



Refuse Disposal : a Practical Manual for Municipal 



Engineers, Members of Local Authorities, etc. 



By E. R. Matthews. Pp. xiv+i6o. (London: 



C. Griffin and Co., Ltd., 1915.) Price 65. net. 

 "/It is the purpose of this work to set forth 

 modern methods of collection and disposal, em- 

 bodying the latest practice, so as to enable the 

 municipal engineer and the local councillor to see 

 what is being done in this and other countries " ; 

 and information of the type usually accumulated 

 by local authorities in their consideration of the 

 problem of refuse disposal is presented in large 

 quantity having regard to limitations of space. 



Given a sound knowledge of the general prin- 

 ciples and practice, the engineer will find the col- 

 lected data with regard to typical plants service- 

 able, but for the councillor some assistance to 

 the intelligent application of the information pre- 

 sented might well have taken the place of certain 

 non-essential detail and superfluous photographs. 



" Discussion " of the advisability of installing 

 destructors for small communities, promised in 

 both preface and text, resolves itself into a de- 

 scription of certain destructors employed in works 

 and institutions, and the statement that destruc- 

 tors "are equally useful for a village of five 

 hundred population as for a city of 500,000." 



The bearing upon the cost of disposal, of the 

 special difficulties of collection, of the provision 

 of adequate attention at the destructor, and of 

 finding any practicable use for the heat generated, 

 in a "village of five hundred population" as com- 

 pared with a city or even an institution, is 

 apparently unrecognised. 



The book deals with the uses of destructor 

 clinker and the construction of chimneys, and 

 concludes with some interesting notes upon the 

 principles of vacuum cleaning and dust collecting. 



P. G. 



A List of Geographical Atlases in the Library of 

 Congress, with Bibliographical Notes. Com- 

 piled under the direction of Philip Lee Phillips. 

 Vol. iii. Titles 3266-4087. (Washington : 

 Government Printing Oflfice, 1914.) 

 The first two volumes of this valuable work were 

 reviewed in Nature in 1910 (vol. Ixxxiv. , p. 325), 

 and as the same general plan and arrangement are 

 followed in vol. iii., a brief notice of this will 

 suffice. It deals almost entirely with acquisitions 

 by the Library of Congress since 1909, but such 

 are the resources at the disposal of this fortunate 

 institution that the present list reaches more than 

 half the bulk of the earlier one. In part this may 

 be due to the somewhat fuller notes and analyses 

 — a feature of great value — but the additions to 

 the collection are extraordinarily numerous and 

 important. They include, e.g., copies of Lafreri's 

 rare Italian atlas, and of Waghenaer's "Specu- 

 lum Nauticum," the absence of both of which was 

 commented on in our previous notice. But few 

 copies of Lafreri, with title, are known, and no 

 two are quite alike ; so that the careful collation 

 now given, and the comparison with Norden- 



