100 NATURE STUDY AND AGRICULTURE 



its physical condition; changes in measured noonday 

 altitude and in the length of day and night; the ecliptic and 

 the zodiac; the apparent annual motion of the sun; the 

 rotation of the star sphere; the poles and the equator; the 

 autumn constellations; the milky way; the planets, noting 

 their changes of position; the general plan of the solar 

 system; eclipses if one occurs. 



Winter. Physical: Systems of lighting in common use; 

 construction and principles involved; incandescent light; 

 arc light; kerosene lamp; gasoline lamp; gasoline car- 

 bureter; acetylene lamp. Study of petroleum; crude 

 petroleum; production; refinement into commercial prod- 

 ucts. Coal gas; manufacture and combustion of coal gas; 

 kinds or grades of coal; peat, lignite, bituminous, cannel 

 and anthracite. Sources of coal and petroleum. Chem- 

 istry of combustion; kindling temperature and burning 

 point. Application of these facts to lighting studied above. 

 Brief reference to the history of the production of fire and 

 its influence upon civilization. 



Spring. Garden: Plant sweet scabious, gaillardia, cos- 

 mos, several varieties of poppy, California poppy; cabbage, 

 broccoli, cauliflower, Brussels sprouts, kohl-rabi, kale, 

 endive; coldframe work in preparing members of the 

 cabbage family for transplanting; continue the study of the 

 annual field and garden weeds begun in the fall; complete 

 the work on the budded peaches; study the flower of the 

 peach, cherry, and the plum as representatives of the rose 

 family and compare with the flowers of other members of 

 the rose family in bloom at this time of year; consider the 

 formation of the fruit from the flower in these fruit trees; 

 note the effects of weather on the flower and fruit crops, 



