SCIENTIFIC READINGS. /* 135 



507. What rivers take their rise from the Alps, what 

 from the Himalayan, and what from the Stony moun- 

 tains ? 



508. How are Lakes sometimes formed ? 



509. Where is the temperature of the ocean the lowest, 

 on its surface, or some fathoms below it ? 



510. What are the causes of Currents? 



511. What are the causes of the change which has 

 taken place on the Earth's surface ? 



512. What change has taken place on the coast of 

 England ? 



513. What is the present situation of Calicut ? 



514. Cite examples of the land having gained on the 

 the sea. 



515. What quantity of matter is on an average annu- 

 ally carried down the Ganges ? 



516. What has been the effect of Downs of sand 

 thrown up by the sea ? 



517. How many Climates are there, and how are they 

 formed ? 



518. What effect has the elevation of a place on the 

 temperature ? 



519. What is the height of Quito and of Mexico above 

 the level of the sea, and the consequence of such ele- 

 vation ? 



520. What effect have mountains on the temperature, 

 and give examples ? 



5 '21. What are the Tramontanes, and what the Siroccos ? 



522. What effect has the cultivation of a country on 

 its temperature ? 



523. What effect has the sea on the temperature, and 

 why are islands less hot than the main lands ? 



524. What effect has climate on the animal and vege- 

 table world ? 



