July 13, 1900.] 



SCIENCE. 



73 



contrast to the broad deep valleys in which 

 the loess was deposited— valleys 3000 feet 

 deep and 2 to 7 miles wide. 



Fred. B. Weight. 

 Tientsin, Nobth China, May 30, 1900. 



POWER OP THE EYE. 



To THE Editor of Science : We often hear 

 people say that they can merely by a steady 

 gaze affect a person at a distance who is not 

 looking at them ; and some say that they are 

 able to make one sitting in front turn the head 

 in this way. Mr. Bell in his ' Tangweera ' (p. 

 198) mentions this feeling when he says : " Pre. 

 sently I felt as if someone was looking at me, 

 and, raising my head, saw a large puma stand- 

 ing ten yards oflf." To the physiologist it may 

 seem uncalled for to investigate a manifest ab- 

 surdity, but it has at least a practical value to 

 explode a common error by direct experiment. 

 I asked a young man, who is very confident of 

 his powers, to stand, unknown to re-agent A, 

 behind a book case, and look through a care- 

 fully concealed peep hole. I gave him the best 

 opportunity, placing A about four feet from the 

 hole and directly facing him, and I engaged A in 

 mechanical writing. To the young man's con- 

 fessed disgust and irritation he was unable to 

 disturb A. My few experiments were negative 

 in results. However, it may be that telepathic 

 influence is exerted under certain conditions, 

 and experiments with twins and others con- 

 stantly en rapport, especially when under emo- 

 tional stress and at critical junctures, might be 

 worth trying. If there be nervous telepathy, 

 this is, perhaps, as simple and common a form 

 as any. If disturbance arose subconsciously 

 the test would be that the tracings from an in- 

 strument to show nervous conditions should 

 show large fluctuations ooincidently with the 

 times when the agent regards himself as suc- 

 cessful. 



Hiram M. Stai^ley. 



CURRENT NOTES ON PHYSIOGRAPHY. 

 glacieres or freezing caverns. 

 A handsome volume under the above title 

 by E. S. Balch has just appeared (Allen, Lane 

 and Scott, Phila., 1900, 337 pages, many illus- 

 trations). Nearly a third of the book is given 



to a narrative of personal experiences in visit- 

 ing ' ice caves ' or freezing caverns in various 

 parts of the world. Fifty pages follow on the 

 causes of subterranean ice ; the first suggested 

 and simplest explanation, the cold of winter, 

 being held sufllcient against a variety of leg- 

 endary and fanciful processes. The prevalent 

 belief that freezing caves are colder in summer 

 than in winter and that ice forms in the warm 

 season is controverted by direct observation. 

 The reason for this curious perversion of fact is 

 probably to be found in the temperature con- 

 trasts between cavern and external air in sum- 

 mer and winter ; the cavern air feeling colder 

 than the open air in summer and warmer in 

 winter. Thermometric records show, however, 

 that cavern temperature is relatively constant 

 all the year round. The whole story is that 

 cold air enters from the outside in winter time 

 and produces ice when there is water to freeze. 

 This simple explanation is confirmed by the oc- 

 currence of glacieres only in regions where the 

 winter has temperatures below freezing. A 

 compendious list of glacieres occupies 100 

 pages ; abstracts of many opinions concerning 

 them, 40 more ; and a good bibliography and 

 index close the volume. The views of the ice 

 stalagmites in the glaciere de Chaux-les-Passa- 

 vant in the French Jura are excellent, and the 

 book as a whole is highly creditable to Amer- 

 ican geographical scholarship. 



the old mountains of MICHIGAN. 



Monograph XXXVI, U. S. Geological Sur- 

 vey, by several authors, treating of the Crystal 

 Falls iron bearing district of the upper peninsula 

 of Michigan, contains an instructive account of 

 physiographic features amid a great body of 

 geologic and economic details. The items here 

 abstracted are from chapters by Smyth and 

 Clements. Although the district is partly un- 

 derlaid by resistant and deformed pre-Cambrian 

 rocks of diverse structures, and partly by weak 

 and gently inclined upper Cambrian sandstones, 

 the most general aspect of its surface is that of 

 a somewhat rolling plain with a gentle and uni- 

 form descent for about thirty miles from an alti- 

 tude of 1800-1900 feet in the northwest to 1200- 

 1300 in the southeast. The areas of harder 

 rocks form broad swells of moderate relief, but 



