December 28, 1900.] 



SCIENCE. 



1003 



After furthei- elaborate proceedings, "'Is 

 this all?' asks the chairman. ' Oh no,' replied 

 Mr. Cartesian, ' there are other proportions in 

 which the ingredients may be combined so as 

 to produce a possible movement,' and he was 

 proceeding to state them when Mr. Common- 

 sense interposed. 'Stop! Stop!' said he, 'I 

 can make nothing out of all these figures. 

 This jargon about x^ y and .~, may suffice for 

 your calculations, but it fails to convey to my 

 mind any clear or concise notion of the move- 

 ments which the body is free to make.' " 



So we might continue quoting every para- 

 graph of this amusing but seriously constructed 

 essay, with equal zest. The book closes with 

 an elaborate bibliography containing all the 

 work relating to the theory of screws from its 

 inception with Poinsot, Chasles, Grassmann, 

 Hamilton, Mobius and Pliicker, to the modern 

 advances of Clifford, Klein and their confreres 

 and Ball himself. Carl Barus. 



Brown University. 



topographic atlas of the united states. 



The second folio of what promises to be a 

 magnificent topographic atlas of the United 

 States, published by the United States Geolog- 

 ical Survey, has recently been issued. This 

 second number, like the first, bears Henry Gan- 

 nett's name, and like its predecessor, also pre- 

 sents illustrations of typical topographic forms 

 for the use primarily of students and teachers 

 of physiography. From the large number of 

 topographic sheets issued by the Geological 

 Survey, ten have been selected which furnish 

 admirable examples of well-developed physio- 

 graphic features, such as a coastal swamp, a 

 graded river, Appalachian ridges, alluvial cones, 

 etc., and bound in a folio, together with brief 

 descriptions and explanations. 



The maps have been well selected and in 

 themselves, so far as one can judge who is not 

 intimately acquainted with the areas repre- 

 sented, are all that could be desired. Not only 

 does the field-work seem to have been carefully 

 executed, but the engraving and printing is 

 excellent. 



The text accompanying each map is intended 

 to supplement and explain the topographic and 

 culture features shown on it. These descrip- 



tions are for the most part evidently compila 

 tions from the writings of geologists and geog- 

 raphers, who have studied the areas represented 

 or other similar regions, although no acknowl- 

 edgments of the sources of information are 

 made. Such references are much to be desired 

 not only injustice to the original investigators, 

 but for the purpose of directing the reader to 

 sources of more extended information. In 

 some instances the maps chosen represent topo- 

 graphic forms which have been carefully studied 

 elsewhere, and might profitably be accompanied 

 by citations from the descriptions of the type 

 examples. Such references and citations could 

 easily be made, as the printed text seldom oc- 

 cupies an entire page : in fact much valuable 

 space is wasted. 



Instructive and pronounced features on some 

 of the maps are not referred to in the text, 

 although there is space available. For example, 

 in the description of the Norfolk sheet, the 

 origin of the drowned stream valley, the prom- 

 inent hills near the ocean's shore presumably 

 dunes, and well-marked characteristics of the 

 shore topography, due to the action of waves 

 and currents, are not mentioned, but in place 

 of such information a questionable explanation 

 of the origin of Lake Drummond is presented. 

 Again, in the text accompanying the excellent 

 map of alluvial cones, no reference is made to 

 the conspicuous channels excavated in their 

 upper portions. 



The pictures in the text are poorly printed, 

 and one of them bearing the objectionable name 

 of 'hogback,' is reversed in reference to right 

 and left ; this reversion throws the picture out 

 of harmony with the diagram beneath it, in- 

 tended to show the structure on which the 

 monoclinal ridge depends. In the title of the 

 picture just referred to — and the same is true 

 in at least one other instance — no reference is 

 made to the geographical position of the scene 

 represented. 



The diagram described as a ' volcanic neck,' 

 might be accepted as representing a cross-sec- 

 tion of a peculiar plutonic intrusion, but by no 

 stretch of the imagination can it be considered 

 as illustrating the structure of a volcanic neck. 

 In attempting to Indicate the ' stratified beds 

 now eroded away ' they are carried completely 



