212 APPENDIX 



13. Usefulness of plants to man Farmers' Bulletins, Nos. 173, 358; 

 Freeman & Chandler, pp. 278-297. 



XIII. WORK AND MACHINES 

 1 



1 . Meaning of the terms work and energy (Any good text in Physios. ) 



2. Classes of levers (Any good text in Physics.) 



3. Pulleys (Any good text in Physics.) 



XIV. MAGNETISM AND ELECTRICITY 



1. Electro-magnets Brownell (Physics), pp. 84-85, 129. (Any good 



text in Physics.) 



2. Electricity and chemical changes (Any good texts in Physics and 



Chemistry.) 



XV. PHENOMENA OF LIGHT 



1. Shadows and eclipses (Any good texts in Astronomy, Physical 



Geography, and Physics.) 



2. Images by reflection Brownell (Physics), pp. 71-74. (Any good 



text in Physics.) 



3. Color phenomena Hooker (Part III), Chaps. XXVII-XXVIII. 



(Any good text in Physics.) 



XVI. THE EARTH AS A PLANET 



1. Day and night and the earth's rotation (Any good texts in As- 



tronomy, and Physical Geography.) 



2. Rotation combined with revolution and changes in seasons Tarr, 



pp. 397-401. (Any good texts in Astronomy, and Physical 

 Geography.) 



3. The moon and its phenomena Crawford, pp. 185-187. (Any 



good text in Astronomy.) 



4. Time and time-keeping, and standard time (Any good texts in 



Astronomy, and Physical Geography.) 



XVII. THE HEAVENS 

 Tarr, 1-6. (Any good text in Astronomy.) 



