137 



ecologists borrowed many ideas from the foresters. Among the 

 notable contributions to science enumerated are the significance 

 of the gregarious habit of trees, the relation of different species 

 to light and shade and humus, the death rate of trees, differences 

 in longevity and productivity of different individuals of the 

 same species, the discovery of a constant ratio between certain 

 measurements of a tree and its volume, regardless of the species, 

 investigations of the properties of wood, the value of forests as 

 soil indicators, the influence of trees on each other and on climate, 

 runoff and soil, the classification of forest types, and the study of 

 the laws of distribution. 



But whether forestry is a science or not depends on the defini- 

 tion of forestry and of science. The prevailing idea of forestry, 

 as admitted by Graves, and to which perhaps no one can reason- 

 ably take exception, is that it is the art of utilizing forests to 

 best advantage. There are many more or less different concep- 

 tions of science, but apparently the only one that does not confuse 

 it with other things is that science is the study of the laws of 

 nature. The mere fact that some foresters have worked out 

 new laws does not prove forestry to be a science, any more than 

 the discovery of some of the laws of physics and human physiol- 

 ogy by engineers and physicians proves engineering and thera- 

 peutics to be sciences. (It is the scientist's business to know 

 why, and the artist's or artisan's to know how.) Most arts, 

 other than the very simplest, are based on one or more sciences, 

 and every science is distinguished from others by laws peculiar to it* 



Forestry is based mostly on the botanical sciences, and the 

 supposed laws of forestry really belong to one or the other of 

 these sciences. For example, the physical properties of wood 

 are matters for the taxonomist to take cognizance of in describing 

 trees, the ratio between dimensions and volume is a principle of 

 morphology — even though the morphologists may not have 

 thought of it before — and the relations of forests to soil and 

 climate are matters of ecology, climatology, etc. Forest men- 

 suration, one of the most important parts of a forester's work, 

 is not a science but an art, which however can be made very 

 useful to scientists, as will be explained farther on. 



* See Science II. 38: 817. Dec. 5, 1913. 



