Notes and Commfnt. 



104 



House of Representatives, entitled "The Influence of Forests on 

 Climate and Floods." Professor Moore's pa-^er is rather sub- 

 versive of opinions that have been long and widely held, indeed 

 he states "I formerly held different views on this subject and I 

 reserve the right to change or still further modify them if the 

 presentation of new facts and figures renders such a course logi- 

 cal, and I do not consider that I will stultify myself in so doing." 

 The principal contention of Professor Moore is that de- 

 forestation does not tend to cause floods, although this main 

 thesis is very much confused throughout the paper with the 

 relation of deforestation to rainfall, in which much learned opin- 

 ion is brought to witness that portions of the globe are treeless 

 because their aridity does not permit the growth of trees, rather 

 than because of the lack of trees inhibiting rainfall. "It is not 

 believed that the cutting of the Cedars of Lebanon had any 

 thing to do with the dryness of the valley of the Jordan." It is 

 further stated as proven that cultivated soils retain water as well 

 as a forest cover does and that snow melts much more suddenly 

 and rapidly in forests than in the open. Quotations from every 

 quarter are brought to demonstrate that the number of floods 

 has not increased in recent years with the increase of deforesta- 

 tion. It seems particularly unfortunate that two pages should 

 have been quoted from a French engineer which can be summed 

 up as showing that "in the basin of the Seine there has been a 

 gradual and constant decrease in the height of floods with the 

 diminution of forests." 



The only serious attempt to prove that floods are no greater 

 after deforestation is made on the basis of the figures for rainfall 

 and for river stages in the Ohio Valley from 1871 to 1908. A 

 comparison of the figures for the first and second halves of this 

 period shows an almost exact agreement, but the figures for 

 the river stages are mean monthly amounts and give no indica- 

 tion whatever of the height of the maxima or lowness of the 

 minima in the curve of the daily fluctuation in the river's flow. 

 As if to be more exact a second table is given showing the number 

 of days that the Ohio and Tennessee were above the flood stage, 

 but giving no indication of how high they were above stage on 

 any particular day or series of days. It is almost as meaning- 

 ess to compare two 19-year periods since 1871 as it is to compare 



