WATER AND WEATHER 35 



as a foot warmer, it would give the feet only .095 as much 

 heat as an equal weight of water ; if a lead weight were used, 

 it would give only .03 1 as much heat as water. Flatirons are 

 made of iron because of the "high specific heat" of iron. 

 They heat slowly and cool slowly, and, when once thoroughly 

 heated they supply the laundress with heat sufficient for a long 

 time. 



Water and weather. About four times as much heat is 

 required to heat a given quantity of water one degree as to 

 heat an equal quantity of earth. In summer, when the rocks 

 and the sand along the shore are burning hot, the ocean and 



FIG. 21. An ocean breeze. FIG. 22. A land breeze. 



lakes are pleasantly cool, although the amount of heat pres- 

 ent in the water is as great as that present in the earth. In 

 winter, long after the rocks and sand have given out their 

 heat and have become cold, the water continues to give out 

 the vast store of heat accumulated during the summer. This 

 explains why lands situated near large bodies of water have 

 less variation in temperature than inland regions. In the 

 summer the water cools the region; in the winter, on the 

 contrary, the water heats the region, and extremes of temper- 

 ature are not great. 



These facts also explain why we sometimes have a land 

 breeze and at other times an ocean breeze. When the air over 

 the land is warmer than that over the ocean, it expands, becomes 

 lighter, and is pushed upward by cooler air which rushes in 

 from over the water. Such an inrush of cooler air from the 



CLARK INTRO. TO SC. 3 



