22 



TIMBER PINES OF THE SOUTHERN UNITED STATES. 



Since the custom of painting and graining woodwork lias given way to natural grain witli oil 

 finish, the wood of tlicsc hard ])iiR'S is becoming very popular for inside finish. 



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

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

 without great injury at high temperatures. 



RATE OF GROWTH. 



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

 they occur. Without going into a detailed discussion, which will be found in tlie 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 ijermit the determination of the rate of growth at 

 different periods of their life. 



Fig. 5. — Binp-ani showinff comparatiTe propreas of height growth in average trees. 



From these it api)ears tliat tlic Cuban I'inc is by far the most rapid grower, while the Longieaf 

 Pin(^, wliic^h usually grows associated with the former, is the slowest, i>obl(illy and Shortleaf 

 occui)ying a position between the two. 



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

 begins then to grow rajtidly and evenly to the fiftieth or seventieth year, and even after that 

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

 height curve a smooth and persistent character. 



The diauieter growth shows the same even and ])ersistent i)rogress from the start, and the 

 volume growth also piogresses evenly alter the rapid height growth rat(i 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 alter the twenty-fifth year leaves the latter 



