538 



SCIENCE. 



[N. S. Vol. XIV. No. 353. 



moraines, the joint product of the Erie and 

 Saginaw lobes of the Laurentide ice sheet. 

 Unusual features abound. ' ' Half-filled valleys 

 and abnormal drainage lines, isolated knobs 

 and morainic outliers, clusters and chains of 

 lakes, kettles and kames conspire with esker- 

 like ridges to produce a type of topography and 

 scenery which seems artificial and almost 

 bizarre." Two of these lakes. High and 

 Gordy's, owe their existence and outline to the 

 presence of eskers, whose origin is ascribed to 

 deposition in tunnels or crevasses in the wast- 

 ing ice sheet. 



THE ONTARIO COAST. 



The Ontario coast between Fairhaven and 

 Sodus bays (near Oswego, N. Y.) is described by 

 J. O. Martin, of Cornell {Amer. Geol, XXVIL, 

 1901, 331-334), as consisting of truncated drum- 

 lins connected by stony beaches which enclose 

 bays and marshes. Active 'long-shore move- 

 ment was noted when waves came obliquely on 

 the shore ; a cobble weighing seven ounces was 

 moved sixteen yards in ten minutes by waves 

 whose breaking height was a foot. The reces- 

 sion of the shore line is rapid, in some cases sev- 

 eral feet a year. The farmers know this, as they 

 have to set back their shore fences fi'om time to 

 time. Several submerged boulder pavements, 

 having the outline of drumlins but standing at 

 a considerable distance off shore, seem to indi- 

 cate former drumlins now swept away. 



GLACIAL CORRIES IN THE CARPATHIANS. 



Recalling a recent note on corries in the 

 Bighorn Mountains of Wyoming, reference may 

 be made to de Martonne's studies of similar 

 forms in the Carpathians (' Sur la Formation des 

 Cirques,' Ann. de Geogr., X., 1901, 10-16. See 

 also Bull. Soc. Geol. France, XXVIII., 1900, 275 

 -819, and Bull. Soc. Sci. Bucharest-Boumanie, 

 IX., 1900, No. 4). After a careful study of 

 several examples, this author concludes not 

 only that cirques or corries are certainly of 

 glacial origin, but that they are as safe indica- 

 tion of glacial action as moraines, striations 

 and rounded rocks ; that they are of longer 

 duration than the latter, and hence of greater 

 value for the detection of somewhat remote 

 glacial periods ; and that they give definite in- 

 dications of the character of the glaciation by 



which they were produced, being due to gla- 

 ciers of the Pyrenean type, and not to a general 

 nor to a local ice sheet. High mountains may 

 thus owe a significant share of their form to 

 glaciation, although whether de Martonne 

 would go as far in this direction as Richter has 

 (see Science, April 5, 1901) does not appear. 



W. M. Davis. 



SHORTER ARTICLES. 

 DEFINITIONS OP PHYSICAL QUANTITIES. 



The standards of ' scholarship ' must be 

 essentially alike in all branches of knowledge, 

 although differences in detail will show them- 

 selves according to the subject. I suppose that 

 the attainment of these standards in the physics 

 of to-day must include accuracy in conceiving 

 fundamental quantities and their connection 

 with each other. Within the past half century 

 much careful thought has been devoted to gain- 

 ing such clear conceptions and constructing a 

 framework of relation among them. In propor- 

 tion as the younger physicists inherit the results 

 of that thought undiminished, they will them- 

 selves be trained for discriminating and exact 

 thinking. It is therefore a matter of regret 

 that some of our leading authorities are habitu- 

 ally lax in presenting certain definitions that 

 are built into the foundations of mathematical 

 physics. I refer particularly to deliberate state- 

 ments found in text-books of great general ex- 

 cellence. These are fair marks for criticism, 

 because they must aim at consistent and system- 

 atic exposition, and because they influence 

 strongly minds that are in the formative stage. 

 Their example should not encourage a student 

 to confound ideas that are really distinct, nor 

 to tolerate inaccuracy in himself. This can be 

 said without implying a demand for pedantic 

 nicety in writing for experts, who are able to 

 catch the right cue, even from an elliptical ex- 

 pression. I shall illustrate my meaning with a 

 few quotations from Professor Thomson's 'Ele- 

 ments of the Mathematical Theory of Elec- 

 tricity,' and from Professor Webster's ' Theory 

 of Electricity and Magnetism.' These are 

 chosen because they are books of acknowledged 

 value ; at the present time each may be taken 

 to register high-water mark within its own 

 range. Since they are representative, we are 



