242 Fourth Conference 



scale of i inch to I mile, a common a very common 

 microscope, with a few glass-slips and cover-glasses, 

 a hammer, and a collecting-bag. The microscope 

 is wanted to show grains of sand, minute fossils in 

 clays, and so forth ; and the structure of a few rocks 

 can be illustrated by half a dozen sections. The use 

 of polarized light and refined mineral conceptions 

 are quite unnecessary from our elementary point of 

 view. There are a good many people who are pre- 

 pared to discuss " Carlsbad twins " and " granophyric 

 structures " who never yet walked across a mountain, 

 or saw "the waters wear the stones, the overflowings 



o 



thereof wash away the dust of the earth ". 



As usual, the teacher must know a good deal more 

 than he puts into his instruction. He must be able 

 to make sketch-sections from the indications of his 

 geological maps, so as to show how the rocks rest 

 on one another, and how they control the features of 

 the landscape. He must also have some conception 

 of the aspect and geological structure of regions out- 

 side that in which he works. But his great aim will 

 be to lead his pupils to observe, and to feel, as it 

 were, the growth and movement, the vitality or 

 decay, of the surface of the earth on which they 

 live. 



We must not expect or even desire them to be at 

 once entranced by the aesthetic and the beautiful ; but 

 we must rather show them Nature doing something, 

 show them her machinery and what is going on. 

 Let us take the brook and its pebbles on one of our 

 afternoon walks. Why is a pebble round? What is 

 the stream doing? The pot-holes in its floor show 

 how it drills away the solid rock. Where does the 



