XVII.] PLANT -EVENT RECORDS. 303 



those products which are very perishable, or for which 

 there exist strong home demands ; and these attributes 

 apply particularly to horticultural crops. The horti- 

 culturist, therefore, is vitally interested in the climate 

 of his particular neighborhood ; and it is the study of 

 this local climate in its relations to plant life which 

 must bring him the greatest good from climatological 

 science. 



If the horticulturist is concerned more with climate 

 than with weather, it follows that meteorological rec- 

 ords, to be of use to him, should be expressed in terms 

 of plant life rather than in terms of degrees of tem- 

 perature or other numerical standards. Very good 

 records could be made by an army of careful growers 

 who had neither a barometer nor a thermometer. Let 

 us suppose, for instance, that the peach -growers of a 

 certain geographical area were to make observations for 

 a number of years upon the relative synchronisms of 

 late frosts and blooming time, a subject which is of 

 the most vital importance to every grower of the ten- 

 der fruits. 



The tabulation of these observations would enable 

 us to construct two series of curves, which would inai- 

 cate at a glance the comparative safety of any station 

 for the cultivation of the given crop. We will suppose 

 that observations have been taken for a number of 

 years by various persons at seventeen closely connected 

 stations, represented by the letters in the margin of 

 the chart, page 305. One curve represents the date 

 of the last killing frost, and the other the date of the 

 opening of the peach flowers. Wherever the frost line 

 lies beyond the bloom line, as in the first five sta- 

 tions, peach growing is impossible. When it lies at 



