RACTICAL ARBORICULTURE 285 



Basswood has averaged a gain of 3.28 inches circumference per annum. 

 Yellow poplar, 2.7 gain per annum. Silver maple, 5.8 gain, growing in four- 

 teen years to be 25.8 inches in diameter. 



The Cottonwood has gained 7 inches girth each year since it was planted. 

 Birches have gained from 3 to 4^2 inches per annum. Ash, 2 l / 2 inches gain. 

 Mulberry. 4 inches gain, the same as Locust. The Catalpa is 15 inches 

 diameter, a gain of 3.4 girth each year. 



The Oaks have gained 2.4 each year. Sweet gum in twenty years gained 

 2.6 inches. White Elm gained 3.2 inches girth. Hickory gained 2.4 inches per 

 annum in the twenty years, while Chestnut made 3 inches additional each 

 year. 



The foregoing tables prove beyond a question that almost every species 

 of our American woods can be grown to a merchantable size, and become 

 a profitable investment within a quarter of a century, many trees increas- 

 ing one inch diameter each year of its existence under most unfavorable situ- 

 ation and conditions. 



With fairly good soils and thorough cultivation, planted more closely 

 to prevent the formation of turf, and more especially if it be a renewal of 

 an old forest, these records should be greatly exceeded. 



