238 



AMERICAN FORESTRY 



Statements like this should overbalance 

 a thousand statement like those in the 

 paper we are considering: 



In the Hoshiarpur district of the Punjab 

 the Siwalik range of hills stretches from the 

 Bias to the Sutlej River in a southeasterly 

 direction. These hills consist of a very soft 

 friable sandstone, alternating with strata of 

 loam and clay. Formerly these hills were 

 fairly well wooded. In 1846 they became 

 British territory; the consequence was a 

 rapid increase of population, a great demand 

 for wood and charcoal in the fertile plains 

 below, and the influx of a floating popula- 

 tion of graziers with large herds of cattle. 

 The result was complete denudation of these 

 hills ; the loose soil, no longer protected by 

 vegetation, was washed down, broad rivers 

 of sand spread into the plains below, and 

 the end has been that fields and gardens of 

 940 villages, once prosperous, are now cov- 

 ered with sand, which has laid waste upward 

 of 70,000 acres of fertile lands. This dis- 

 trict, rich formerly, is now traversed by nu- 

 merous broad, parallel sandy belts, cut out 

 of the fertile and crop-bearing area. 



Efficient protection of the reserved forests 

 was only commenced a comparatively short 

 time ago, and yet the author is able to state 

 numerous instances from different parts of 

 the country, in which protection has com 

 pletely changed the character of the torrents 

 and streams taking their rise in the forests. 

 After rain, the water no longer rushes down, 

 carrying sand and silt with it; the channels 

 have been confined into permanent beds; they 

 have become narrower and deeper, and the 

 old beds to the edge of the channel have be- 

 come stocked with grass and thousands of 

 seedlings. * * * The denser vegetation, 

 which is the result of efficient protection, has 

 everywhere counteracted erosion, has pre- 

 vented landslips and sudden floods.* 



ARE FLOODS INCREASING 



Professor Moore devoted thirteen 

 pages of his thirty-six to the discussion 

 of this matter, in which he criticised the 

 discussion of Mr. Leighton of the Geo- 

 logical Survey, and of IMessrs. Hall and 

 Maxwell of the Forest Service. His 

 objections to these two papers are the 

 following: 



First : He claims that they discuss 

 "not floods as such, but moderate stages 

 of the river." 



Second : He maintains that their 

 method of discussing the observations 

 is incorrect. 



I have not at my disposal the records 

 bearing upon this matter and therefore 



^Nature, April iS, 1901. 



cannot, even were it desirable, here dis- 

 cuss them in full. Mr. Leighton's dis- 

 cussion of the Tennessee River com- 

 pares the conditions existing in the 

 twelve years 1884 to 1895 with those 

 existing in the twelve years 1896 to 

 1907. . Professor Moore admits that 

 this period of time is too small to allow 

 of definite conclusions being drawn. He 

 further says that "no records or other 

 evidence are presented that there is not 

 as much forest area in this basin as 

 there was twelve years ago." The most 

 that can be said, therefore, with refer- 

 ence to this discussion is that the evi- 

 dence is not sufficient to justify definite 

 conclusions either way. Personally, I 

 think the figures given by Mr. Leighton 

 indicate an increase in floods, but not 

 having the full data at hand, and particu- 

 larly data as to the forested area. I believe 

 this is simply another illustration of the 

 fact that the statistical method is of very 

 limited use, and perhaps of no use at 

 all, in the case of meteorological and 

 hydrological phenomena covering so 

 short a period of time. Professor Moore 

 apparently takes the same view, for he 

 says : "No matter how complete the data 

 may be or how fundamentally sound 

 and fair its collation and grouping, the 

 comparison, the one with the other, of 

 such short periods as those measured 

 by only twelve years cannot give results 

 with regard to changes in climate and 

 floods that will permit the most skilled 

 meteorologist or engineer to draw fun- 

 damental conclusions that can have any 

 value." 



If Professor Moore had stopped here 

 we could agree with him on this point. 

 I 'n fortunately, however, he goes on to 

 give what he considers a different and 

 more reliable form of investigating this 

 (|uestion of the relation of precipitation 

 to run-off. For this purpose he takes 

 the records of the height of the Ohio 

 River at Cincinnati from 1871 to 1908, 

 and from a consideration of these re- 

 sults he draws the following definite 

 conclusions: (p. 33) 



"The average discharge of the Ohio 

 River where, / presume, deforestation 

 has been as great as in any other part 

 of the country during recent titnes, has 

 not changed for a period of thirty-eight 



