Bisbee daily review., 1909-01-19
 GOOD TIMBER
 IN MINING
Few Persons Who Should Know Realize How Much Depends On It-Some Hints To Mine Owners.

Few persons not directly interes. ed in mining realize the extent to which timber is used in this very il. portant industry" said a Government expert in preservation Of mine timber who has just returned to WashingtUI. from the West. ''rhe average man has only a vague understanding of the importance of the part that li1lI Der plays in the mining industry and seldom tn nks of the enormous quan- titles required each year to preven. the caying of the over-hanging ground and to keep clear the main working passages of the mines.
 There are two general classes of suca t-mbers,' he continued. the first is used in bracing the 'stopes' as they are called where the ore Is being taken out. As the ore is mliit.u the surrounding rock is held in Dla,- l by brac.ng 1t with leavy timberS. framed" into rectangular sets When ore directly above the first set Is removed. 2 second set is built in on top, and so on. The service of thes-. timbers ends when the ore is eS- hausted and the active m ming trans ferred to another vein or ore-body. After a time these timbers decay, 10 Doint Where the pressure of the rock walls crushes them, and cave in occurs. Tais causes no damage ii. as l nave said. he mining wui !. has been finished; but Il sometimes nappens that decay has wsakened the | timbers to sucA an exteEz that tiis eaye-in occurs premetureiy. aud then hyes are sacrificed. ia such eases tke remaining ore is alsd loss, tor when the ground once commences to move or work, es tho miners can is, It g @imost impossible to clean f out and hold back the rock so that
 Cne remain,ns ore may oe obtaihsa But Of still greitsr imp0Tancs r. the second class Of timbe-5 used .L the main working openings, tunnels, shafts, etc, which are to be main tained for as long a time as possible
 Tmbers for this service are chosen not only for their strength ana Inui- ness, but also for their ability 10 iv- sist decay.
 Tn nIne cases out of ten, when tim hers are crusled, the indirect causs, is decay produced by low forms or plant life. The dwindl.ng of cur tim Ter supply has driven consumers ol
 wood all over the country to stuay
 decay and it's prevention, and it is
 safe to say that in the very near fu- ture we shall see many more mines
 putting in smaIl plants for the treat
 mant of their timbers, after the pat tern of he plants that have been de | Q gned and installed for this purpose | Dy the United States Forest Service. | By thrc ating the permanent timbers
 with some one Of the various preserv- ] .,tnes, tAey may be made to resist decay almost indefinitely. The addi- < tional cost is light
 "Nos only this, but since timber
 when 1t is once treated retains its original strength, many of the SO
 ca led inferior timbers' wnica have
 hitherto been considered almost value less because they decay rapidly, will
 find use in many localities. Suca
 species are loblolly pine and. to a ceI-
 tain extent shortleaf pine, Engleman
 spruce, firekilled lodgepole pine, wHIto
 fir, and many other more local tim
 bers
 The first of the treating plants for
 mine tinbers was put up by an east
 ern coal company, after extensive eN-
 periments in cooperation with tho
 Forest Service which demonstrated
 the practical value of the treatments.
 Since then, other plants of the coun-
 try, two of the latest being in the
 Occur d'Alene lead district of north
 eTn Idaho where, while there is an
 ample timber supply for some time to
 come, the treatment is warranted by
 the high labor cost of replacing tim
 Der sets. The added cost of treating
 timbers is from 10 to 25 cents of the original cost.
 An interesting point in the prob
 lem of wood preservation is the spread tof decay in old workings, causeu Ds infection from nearby timbers. A fresh green post. placed between tNO sticks that are already sick will be- come infacted and decay inucd more rapidly that if 1t were isolated. The lcontagion is similar to that of the ills that man is heir to, although 1t usually works more slowly. h. O..s large niue a two file tunnel was com pleted eight years ago and during C,a~ first four years the timber stood up in fine shape Then signs of decay began to creep in here and there, anu since then the disease has extended throughout the entire length of une tunnel, necessitating an annual eA- penditure of between four and five thousand dollars for replacing timbers through decay. less than one-fourth of this sum goes for timber, the remainder s-epre,ssniIng the cost of framing and installing Unquestionably many Of the cave-ins which crush the timbers and black the mine tunels. often causing mans deaths are due to nothing but wood decay.
 The work of treating mine tfmbers is considered of such importance tnat one group of men in the Forest Ser vice gives It's entire attention to thIs subject IRvestigative work carried on by this branch of the Service since |it was organized has demonstrated that. treating with an efficient preses ative will proiong the life of timber Indefinitely in places where before lit was subject to rapid decay. and the interest shown by the large Svai- sumers of timber and their eagerness to supply the information that has been obtained to their own particular problems has been widespread ana oF tf... t.anofffe of Wo,f