70 



60 



1 23456789 10 11 12 



YEARS 



Fig. 21 — Depreciation curves for %-inch southern pine sapwood stakes treated 

 with creosote. BTL 5286A. 



90 



80 



p50 



Q 



Z 



8 40 



££ 30 



20 



1 2 3 4 5 6 7 8 9 10 It 12 13 



YEARS 



Fig. 22 — Depreciation curves for ^-inch southern pine sapwood stakes treated 

 with creosote, BTL-5285A. 



437 



