April 24, 1896.] 



SCIENCE. 



615 



that can be obtained in the way of work 

 which relates to causes of action, and thus, 

 for the reason that men, however great their 

 training may otherwise be, are unlikely to 

 conceive the earth about them as a realm 

 of continuous processes, their geology is 

 thus not brought down to the present 

 period. The beds and banks of the streams, 

 the retreating escarpments, the shores of 

 lakes and of the ocean — above all the, when 

 rightly discerned, majestic phenomena of 

 the soil — all may serve to impress the pupil 

 with the activity of the earth, and thus clear 

 his mind of the natural but blinding con- 

 ception that after its creation time the 

 sphere entered on an enduring rest. 



Difficulties Enccmntered in Field Teaching. 

 In my experience the difiBculties which 

 have to be m.et in field teaching, apart from 

 the hard labor involved in the simultane- 

 ous exercise of mind and body, consists in 

 the struggle which the instructor has to 

 make with the incapacities which arise 

 from the supei-civilization of his pupils. 

 These hindrances are protean in form, but 

 they are most commonly to be found in an 

 inability to think in three dimensions any 

 Ijetter than we can in four, and an inca- 

 pacity to continue any work when alone. 

 As to the iirst of these defects there seems 

 to be no resource except to revive the 

 natural dimensional sense which primitive 

 people have. If the student has had sound 

 training in solid geometry he may the more 

 quickly recover the capacity to form the 

 special conceptions which are required of 

 the geologist ; but the natural solid is quite 

 another thing from the ideal, and while the 

 theoretical view of them is the same the 

 practical experience is very different. Some 

 youths never learn to deal with the earth 

 problems from the solid point of view. 

 Thej' are therefore cut off from the better 

 uses of the field ; yet even with this signal 

 disadvantage they may do good work in cer- 



tain parts of the science. One of the most 

 distingushed of our American geologists, 

 now dead, was, perhaps on account of the 

 fact that he saw from but one eye, quite 

 without the sense of the relations of the 

 solid ; yet, while in the field work his suc- 

 cess as measured by his talent was limited, 

 his contributions in other departments were 

 great and of enduring value. Neverthe- 

 less, though the people who abide in two 

 dimensional spaces may possess abilities of 

 a high order, they should be kept out of the 

 science which more than any other calls for 

 the ability to frame three dimensional con- 

 ceptions. 



An inability to work alone in the field is 

 a rather common, and in my experience an 

 incurable, defect in certain students who 

 would otherwise be fitted for geology. 

 Those who are thus afflicted appear to lose 

 their motive of inquiry when they are parted 

 from their fellow men. Their malady is to 

 be regarded as one of the many defects of 

 body and mind which are due to over-hous- 

 ing — to that absolute separation from the 

 peace of the wilderness which character- 

 izes our city life. 



As soon as possible the field student 

 should be brought to the point vs'here he is 

 required to make his own maps, at first as 

 sketches, and then in the more formal way 

 by pacing, with some methodical control, 

 such as by a simple triangulation. One 

 piece of such map work where the delinea- 

 tion of the surface in general ground plan 

 and contour, as well as the geological color- 

 ing, is from his own labor will often be 

 sufi&cient to affirm the working power of 

 the man. In the ideal of the system such 

 instruction should come to every student 

 who undertakes the study of geology, but 

 in practice it will probably be gained by 

 very few. In the department of Harvard 

 University which is devoted to the science 

 300 men each year enter on the elementary 

 work. Of these not more than the eighth 



