PREFACE. 



Several experts in agricnltnral science having stated to me their 

 need of a systematic summarv of the present state of our knowledge 

 with regard to the specific influence of climate in agriculture and its 

 relation to or absolute effect on the percentages of the resulting har- 

 vest, and the subject being one in which I had long been interested, 

 I therefore presented the matter to the Chief Signal Officer, who 

 thereupon issued an instruction, dated February 25, 1891, authorizing 

 me to prepare this work, completing it before June 30 of that year. 

 The present report is a rapid compilation from a wide range of 

 sources, and presents a preliminary view of the condition of our 

 knowledge at that time as to the effect of climate upon the gi'owth 

 and distribution of our staple crops. As far as practic?Mc I have 

 presented, in the words of the respective authors, the results of their 

 own investigations on the points at issue, my owm duty being not to 

 undertake any extensive original study, but to merely connect their 

 results together in a logical manner, to collect data for future general 

 use, and to suggest, or stimulate, further inquiry on the points here 

 presented. I regi'et that the report could not have been published 

 in 1891, as many of the ideas presented therein have by delay thus 

 been withheld from their practical applications to the benefit of 

 agriculture. 



As the study of phenology and agriculture, in the modern* spirit, 

 has been cultivated for over a century in Europe, much of our knowl- 

 edge must be drawn from European literature, which is really far 

 too extensive to be satisfactorily summarized in the time and space 

 at my disposal. Originally it was my hope to introduce into this 

 report a sunnnary of the large and sadly scattered literature of 

 American phenology, including the dates of l)lossoming and ripening 

 both of natiA'e and cultivated ])lants, enlarging the work already done 

 in this line by F. B. Hough for the State of New York; but I did not 

 succeed in completing this part of the work, and reserve it for a 

 future occasion. Requests for phenological observations in the 

 United States have been frequently made since 1800. and large collec- 

 tions of data exist in manuscript and print sufficiently extensive to 

 justify the hope that they may prove worthy of a study as elaborate 



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