126 NATURE STUDY BY GRADES 



planting, and the implements used in these activities, also 

 should be studied. 



Predatory animals and insect pests, the particular evil 

 wrought by each, and the means adopted by the farmer to 

 protect his animals and crops from them, also should receive 

 attention. 



Besides affording splendid opportunities for nature study, 

 such a trip will form a theme for the choicest language 

 work and art, and may be made the basis of the his- 

 tory and evolution of farming and farm implements. It 

 thus becomes the natural means of the most valuable cor- 

 relation of useful thought and knowledge. 



Discuss subsequently each crop produced : how it is 

 grown, harvested, and marketed. It will be found that 

 the farm is the source of supply for a great number of the 

 most necessary commodities. Base as many lessons upon 

 the visit as may be advisable. 



LESSON II 

 THE THERMOMETER 



Every schoolroom should contain a thermometer. One 

 may be purchased for twenty cents that will serve for ordi- 

 nary use, but one that will indicate boiling point and be 

 more accurate will cost one dollar or more. To tell the 

 temperature of the air indoors or out, the thermometer 

 should be so placed as not to receive undue heat from the 

 stove or radiator, or from the rays of the sun. . 



Experiment. Let the pupils examine a thermometer, 

 breathe on it, etc., to see the mercury rise and fall. Explain its 

 action. Plunge it into melting ice, if convenient. Note the 

 temperature. Place it in boiling water. Note this temperature. 



