14 ^NATURE STUDY REVIEW [10:1— Jan., 1914 



The subject of eclipses both lunar and solar can be made intel- 

 ligible by the use of a single diagram as shown in Fig. 7. A few 

 simple experiments with a light and shadows will help to make 

 such a diagram better understood. 



The teacher who wishes to make use of astronomy as a basis 

 for nature-study work should become familiar with some text 

 book in the subject, not too large and written in a popular style. 

 A too technical book will discourage by the mass of detail given 

 which, fortunately, is out of place in a nature-study course. 



No reference has been made to the use of a telescope and it is by 

 no means essential. If some one in the community possesses an 

 instrument which could be made available for use of the school it 

 would greatly increase interest in the subject. 



The Lay of the Land 



James G. Needham 



Chief of all land laws is the law of gravity. 



The solid crust of the earth is overspread with a thin film 

 of loose materials that collectively we call the soil. How 

 thin a film it is as compared with the great mass of the earth \ 

 Yet it is the abode and the source of sustenance of all the 

 life of the land. It enfolds and nourishes the roots of all the 

 trees and herbage. It clothes itself with ever-renewing 

 verdure. On it we live and move. From it we draw our 

 sustenance. We usually mean this thin top layer when we 

 speak of the land. 



This film of soil covers the rocky earth-crust with great 

 irregularity as to distribution and depth; for its materials 

 are derived in the main from the weathering of the rocks. 

 Alternating frost and sun have broken them to fragments; 

 attrition and chemical action have progressively reduced 

 the fragments to dust; wind and flood have mixed them 

 and mingled with them the products of life and decay. 

 Sun and frost and rain and wind and life and decay act 

 intermittently but gravity operates all the time. Weather- 

 ing and gravity are the great factors in the modeling of the 

 landscape. While weathering gleans the basic soil materials 



