8? 
The works, at Santa F6, which have within a year been riveted on the 
plans and partly under the supervision of Mr. (). Ohanute, 0. E.j arc 
constructed and operated in accordance withal! the requirements of the 
best modern practice. At the Las Vegas works an accurate and full 
record is being kept of all the operations and of all expenditures, more 
complete than has ever been approached, 80 far as I know, in this or 
probably any other country, and which, when published in full, will 
give more trustworthy information as to the cost of wood preservation 
than lias heretofore been obtainable. 
The data contained in these reports, which have been kindly fur. 
uished to me through Col. Edgar T. Ensign, forestry commissioner of 
Colorado, have been very useful in determining the comparative cost of 
the several processes now in use for the preservation of wood. 
Whether the use of glue and tannin in connection with the zinc 
chloride will prove a success or not, the works erected under Mr. Cha- 
nute's directions, and the methodical system of operating them initi- 
ated by him, will do as much for the proper preservation of timber by 
mineral salts as Andrews, at Boston, and J. W. Putnam, in the South, 
have done for the proper application of the creosoting process. 
3. The Zinc-gypsum Process.— The process was patented by Mr. Hagen, 
of Saint Louis, and is used by the American Wood Preserving Com- 
pany. In this process the timber is impregnated with a solution con- 
taining both chloride of zinc and gypsum. When the water of the so- 
lution evaporates the gypsum crystallizes and is expected to stop up 
the pores of the wood, and thus prevent the washing out of the zinc- 
chloride. The question arises, whether a substance soluble in water to 
some extent like gypsum can be expected to permanently stop up the 
pores of the wood against the ingress and egress of water. It seems 
hardly possible that the gypsum would answer the purpose. The best 
that can be said for this process is, that if the addition of gypsum does 
no good it cannot do harm, and that if the wood is impregnated 
thoroughly with a solution of chloride of zinc and gypsum it will last as 
well at least as wood simply Burnettized. 
4. The Zinc Creosote Process.— A process has lately been proposed by . 
Mr. Jas. T. Card, President of the Wood Preserving Works at Chicago, 
111., viz: To impregnate the timber first with chloride of zinc, and after 
partially removing the moisture from the wood to inject dead oil through 
the outer portions of it, thereby securing, as Mr. Card states, " all the 
benefits derived from the oil when lumber comes into contact with the 
ground, as w r ell as insuring thorough treatment of the wood, through 
chloride of zinc, which is protected by the oil surrounding it, thus pre- 
venting its being chemically changed or washed out." 
The process seems rational, and would probably answer a good pur- 
