ADDRESS BY THE PRESIDENT, NOVEMBER 7, 1873. 119 



Association at Bradford in September. Two localities were selected 

 after much correspondence, and in one (Carnwath) the recording 

 of systematic observations has commenced. The subject is con- 

 fessedly a most difficult one to investigate, and I would caution you 

 against forming conclusions from the experience of one or two 

 years, and not to expect much from the observations in one locality. 



In regard to this inquiry, " Man and Nature," * by the Hon, 

 G. P. Marsh, United States Plenipotentiary at Florence, is a most 

 interesting and valuable work, treating the subject broadly and 

 generally, recording many remarkable facts in history and physical 

 geography; but the author does not attack the subject instrumental! y, 

 or enter upon a rigid inquiry based upon numerical data. Indeed, 

 our best meteorologists admit that we are not in a position at 

 present to grapple with the problem directly by instrumental obser- 

 vation. For, from the capricious distribution of the rainfall at all 

 times, many years must be allowed to elapse (at least twenty or 

 thirty years) before the influence of forests on the rainfall can be 

 unmistakably indicated from the data collected by gauges, suppos- 

 ing even that rain gauges are planted over a district in positions 

 suited for the proper investigation of this question. 



The only satisfactory means of investigation that can be recom- 

 mended as likely to lead to successful results is to consider it as 

 part of the more general question, viz., the influence afforests on 

 climate, particularly on the two great elements of climate, tempera- 

 ture and humidity. This branch of tbe question has not been 

 investigated with so much success as has attended Mr Marsh's 

 inquiries into that part of the problem with which he deals. In- 

 deed, the examination of the temperature and humidity can only be 

 said to have commenced. In Prance, Becquerel has given a good 

 deal of attention to the question, and published the results of his 

 investigation concerning it, but these are unfortunately unaccom- 

 panied by the requisite details, and the conditions under which 

 the temperatures were observed are not stated with sufficient 

 exactness. Signor Eivoli in Italy, Paul de la Cour in Denmark, 

 and some others, have done a little in the investigation of the 

 subject. But Mr Buchan, Secretary to the Scottish Meteoro- 

 logical Society, informs me that the most systematic series of 

 observations set on foot in the prosecution of this inquiry are those 

 of Ebermeyer in connection with the forest school at Aschaffenburg 

 in Bavaria, of which the results are regularly published. 

 * London 1804, and Flomu-p 1870. 



