22 



TIMBER PINES OF THE SOUTHERN UNITED l>TAT£S. 



Since tbe custom of painting and graining- woodwork has given way to natural grain with oil 

 finish, the wood of these hard pines is becoming very popular for inside finish. 



Kiln-drying is successfully practiced with all four species, but especially with the Shortleaf 

 and Loblolly pines which, if not artificially seasoned, are liable to "blue." The wood can be dried 

 without great injury rt high temperatures. 



RATE OF GROWTH. 



The species naturally develop somewhat differently, according to the soil conditions in which 

 they occur. Without going into a detailed discussion, which will be found in the body of this 

 work under each species, a comparison of the rate of growth of the four species, based on a large 

 number of measurements, gave, for average trees and average conditions, the results shown in the 

 accompanying diagrams (figs. 5 to 7), which permit the determination of the rate of growth at 

 different periods of their life. 



Fig. 5.— Diagram sho-mng comparative progress of hcigbt groivtli in average trees. 



From these it appears that the Cuban Pine is by far the most rapid grower, while the Longleaf 

 Pine, which usually grows associated with the former, is the slowest. Loblolly and Shortleaf 

 occupying a position between the two. 



The Longleaf shows for the first five to seven years hardly any development in height and 

 begins then to grow i-apidly and evenly to the fiftieth or seventieth year, and even after that 

 period, though the rate is somewhat diminished, progresses evenly and steadily, giving to the 

 height curve a smooth and persistent character. 



The diameter growth shows the same even and persistent progress from the start, and the 

 volume growth also progresses evenly after the rapid height growth rate is passed at seventy years. 



The Cuban Pine ceases in its maximum rate of height growth at thirty years, starts with its 

 diameter growth at about the rate of the Loblolly, but after the twenty-fifth year leaves the latter 



