Geology and Natural History. .81 



neighborhood of high masts it should be insulated from the earth 

 and the resonance of the wires leading to the parts of the appara- 

 tus should be obviated. Wires which are at right angles to the 

 antennae and to the line connecting sending and receiving 

 intruments exercise no influence. Trees and buildings diminish 

 the energy received if they lie between the sending and receiv- 

 ing instruments ; if they lie behind the apparatus at sending and 

 receiving stations they can in certain cases form standing waves 

 which strengthen the result. — Ann. der JPhysik, No. 12, 1905, 

 pp. 348-371. J. t. 



11. JEleJctrische Kraftubertragung • von Wilhelm Philippi. 

 Pp.'viii, 386, 321 figures, 4 plates. Leipzig, 1905 (S. Hirzel). — 

 The literature of electricity, particularly on the technical side, 

 owes much to the contributions which have been made from the 

 German press. The present volume illustrates this well, being a 

 very thorough and admirable presentation of a subject of more 

 than usual importance. The author deserves praise not only for 

 the clear presentation of the facts which he sets before the 

 reader, but also for his discrimination in omitting many things 

 which would have required much space and are of minor import- 

 ance. Thus, although presenting in simple form some of the 

 fundamental principles involved, for the benefit of the non-spec- 

 ialist, he omits the descriptions of individual machines and 

 apparatus which are to be found in the catalogues of makers. 

 Furthermore, while going very fully into the subject of the vari- 

 ous plants in Germany and abroad, where electricity is being used 

 as motive power, he limits himself to establishments where the 

 conditions are peculiar and of special interest, leaving those 

 which involve only the usual principles with brief notice only. 

 The mining and smelting establishments and rolling mills are 

 treated with particular fulness ; the dicussion of the two last 

 having been prepared by Dr. Georg Meyer. A detailed account 

 as to what the work contains would involve enumeration of the 

 various forms of single phase and multiple phase motors, trans- 

 formers, etc., but a general statment must suffice. The presenta- 

 tion is throughout clear and thorough and illustrations are used 

 very freely, the comparatively large size of the page giving good 

 opportunity for this. 



II. Geology and Natural History. 



1. United States Geological Survey. — Recent publications of 

 the U. S. Geological Survey are contained in the following list. 



Folio : No. 126. — Description of Bradshaw Mountains Quad- 

 rangle ; by T. A. Jaggar, Jr. and Charles Palache. 



Professional Papers: No. 37. — The Southern Appalachian 

 Forests ; by H. B. Atres and W. W. Ashe. Pp. 291, with 37 

 plates and two figures. 



Am. Jour. Sci. — Fourth Series, Vol. XXI, No. 121. — January, 1906. 

 6 



