652 EXPERIMENT STATION RECORD, 



mension stock, altlioiisli it is iiiitit for incli stuff owing to tlio fi-equpnt cross 

 checks. 



The general conclusion is reached that sound dead timber, i)articularly when 

 fire-killed, has decided value and keeps this value for a considerable length of 

 time. It does not decay readily, is not impaired by standing in a dead condition, 

 and is perfectly seasoned, easily handled, and cheap to ship. Owing to the ab 

 sence of watery sap it is in good condition for preservative treatment. Its use 

 is recommended wherever checking is not a detriment, both as a prevention 

 of waste and the saving of more valuable timber for better uses. 



The preservative treatment of fence posts, H. F. Weiss (U. S. Dept. Agr., 

 Forest tierv. Circ. Ill, pp. 15, fig. 1). — This circular contains an account of ex 

 periments conducted by the Forest Service with a view of determining an 

 economical commercial method of impregnating fence posts with ci'eosote. Tho> 

 experiments are described, the results ai;e tabulated and briefly discussed, and 

 some conclusions are deduced which are of general application in fence post 

 treatment. 



Initial experiments were conducted in cooperation with the Bureau of Plant 

 Industry during the Ijouisiana Purchase Exposition at St. Louis in 1904, in 

 which posts cut from maple, elm, sycamore, ash, Cottonwood, sassafras, hickory, 

 black walnut, water oak, willow, and red oak were treated. Further experi- 

 ments were conducted at Elwood and Iais Angeles, Cal., with lilue, red, 

 and sugar gums, and ironbark. With the results secured from these first experi- 

 ments as a guide, more complete experiments were made at St. Anthony, Idaho, 

 in IttOd. in treating fence posts cut from fire-killed lodgepole pine. The open 

 tank treatment was used in all of the tests. In all 18 kinds of wood were 

 treated and a table is given showing the resulting [)enetration in each case. 



The experiments at St. Anthonj' were divided into three series, in which it 

 was sought to determine the minimum of efficient temperature for the hot creo- 

 sote, the minimum efficient duration of the bath in hot creosote, and the mini-' 

 mum efficient duration of immersion in the creosote after shutting off the heat. 

 These results are tabulated and show that the hotter the creosote the greater the 

 absorption and penetration. Within fixed limits increased duration of the bath 

 in hot creosote, other factors being equal, gives greater absorption and penetra- 

 tion. This is also said to hold true with regard to the duration of immersion 

 in the cooling creosote. The effect of a long period in hot creosote with a short 

 period in cool creosote has not thus far been determined. 



Tabulated data are given showing the comparative cost of untreated 

 qnd treated posts of lodgepole pine in Idaho. The estimated annual cost of an 

 untreated post is given as 5 cts., and of a treated post as 3 cts. Thus it is 

 figured that at the end of 20 years a creosoted fence will be about 40 cts. per 

 post cheaper than if untreated. Based upon these results some general direc- 

 tions are given relative to the selection, prer)aration, and treatment of fence 

 posts. 



Introductory statements deal with the growing need for the preservative treat- 

 ment of fence posts, causes of decay, and preservative methods now' in use. 



New wood preservative, J. A. Van Hek (Daily Consular and Trades Rpts. 

 \U. /S.], 1901, A'o. 2921, p. 10). — The author reports tliat recent experiments in 

 Belgium on the preservation of wood, made with a new coal-tar extract known 

 as '* injectol," have given satisfactorj- results. In the experiments injectol was 

 applied to wooden poles, railway ties, and blocks used in street paving. 



As compared with creosoted poles in the ground, which resisted decay for only 

 a few months' time, those treated with injectol remained unattacked after 3 

 years. Similar experiments were also made with railway ties, these being 

 treated with coal creosote, creosote and chlorid of zinc, and with injectol, and 



