ia ` Instruction in Geological Investigation. [Sept 
ply the tests that furnish him with answers to such questions as l 
these. He must make a second and a third attack before he | 
really gets possession of all the facts about the dike,—its width, 
dip, and direction; the detail of its contact phenomena; its tex- 
ture and its joints; but by persevering attention all these facts 
can be discovered from his own seeing, and then a good lesson 
is learned. A few such lessons correct the habit of using words 
recklessly, of making guesses and of offering unjustifiable sug- 
gestions in explanation of discovered facts. All this is very ele 
mentary ; but it is the only basis for good work ofa higher order. | 
The better students take to the work with fine spirit; in some | 
cases the opening of their eyes, the awakening of the conscious | 
ness that the work is in their hands and that they are really able 
to undertake it, is an inspiring experience to the instructor,—om 
that serves to carry him over the disappointment occasioned by 
the obdurate youths who insist that they, who have most ® 
learn, cannot learn anything from the quarry before them. Itis 
indeed a real ‘pleasure to go with an appreciative new-comer to 
an old, familiar field and watch his rapid learning of new facts 
and methods: it is this that saves teaching from becoming M% | 
notonous, and makes it instead a very live work. t 
It is not always easy to secure a good conception of the truth 
and actuality of phenomena that are named and talked about 
familiarly enough; for i 
example, the intrusion f 
of the dike that has J | 
been discovered. 5006 | 
little commonplace E 
amined — minutely 
ried away out of sight in the further widening of the git i 
