'9U] OF THE UNITED STATES. 263 



have been planned and are carried out mainly not for the study of 

 climate as it may influence plant growth but for the study of meteor- 

 ology and climatology and for weather prediction; second, the 

 methods now employed for handling the observational data after 

 they have been obtained are not well suited to the study of the cli- 

 matic relations of plants. To make these propositions clear, we may 

 consider the work of the United States Weather Bureau, this work 

 being familiar to all of us and having a direct bearing upon the prob- 

 lems of plant distribution as I have been led to attack them. Al- 

 though the Weather Bureau is officially a part of the national De- 

 partment of Agriculture, being one of the largest bureaus of that 

 department, its main activities have neven been primarily directed 

 towards the relation between agriculture and climatology. Weather 

 prediction and weather history seem to have been almost the sole 

 scientific aims of the organization up to the present time. The stu^ 

 dent of plant activities will find no fault with these aims, but he may 

 wonder how it has come about that an agricultural bureau has so 

 thoroughly ignored what we must regard as by far the most impor- 

 tant relation which exists between human welfare and climate; that 

 is, the relation between plant growth and the climatic features of 

 plant surroundings. 



As to the making of climatic observations, it is clear that observa- 

 tories in the rural districts are the only ones whose records are prop- 

 erly available for our present purposes. It is a curious fact which 

 speaks for the political or commercial rather than scientific nature 

 of our Bureau's organization, that the best equipped observatories 

 in this country are generally located in large cities, and usually high 

 in the air. As the population of the United States has increased 

 you may note a somewhat parallel increase in the average distance 

 of the climatic observatories from the ground. This of course ought 

 not to be. If political and commercial interests demand observa- 

 tories in the urban districts the records from these should be treated 

 only as special studies of special conditions. It is interesting to 

 note that the charts of Day's^ recent bulletin upon frost data have 



^ Day, P. C, " Frost Data of the United States," etc., U. S. Dept. Agric. 

 Weather Bureau Bulletin V, 191 1. 



