10 



THE RUBBER INDUSTRY 



flood-level would be required, and to build anything of 

 the kind in a country where stone is rarely found would 

 entail an expenditure out of all proportion to any 

 possible results to be obtained from a colonization or 

 agricultural standpoint. 



In such a vast extension of territory as that com- 

 prised within the area embraced by the Amazon Valley, 

 considerable difference of climate must necessarily 

 exist ; but throughout a very large section, more 

 especially in those districts where rubber-yielding trees 

 are most abundant, the variations of temperature are 

 not so great as might be expected. In the portion of 

 the Amazon Valley situated between the Atlantic coast 

 and Porto Velho, a distance of 1,600 miles, the follow- 

 ing results were obtained as the average maximum and 

 minimum records, extending over a period of the five 

 years from 1907 to 1912 : 



No accurate statistics are available to determine any 

 variations at other points ; but the deductions to be 

 drawn from occasional reports and observations are 



