. Canadian forest industries 1894-1896. Lumbering; Forests and forestry; Forest products; Wood-pulp industry; Wood-using industries. simultaneously adjusted either vertically or horizontally, substantially as herein specified. EFFECTS OF KILN-DRYING- After a long-range investigation of the sub- ject, the Forestry Division of the Agricultural Department at Washington, sums up the evi- dence as to the effects of kiln-drying native woods as follows : Although kiln-drying has become quite uni- versal, opinions are still divided as to its effects upon the strength of the material and other qualitie
. Canadian forest industries 1894-1896. Lumbering; Forests and forestry; Forest products; Wood-pulp industry; Wood-using industries. simultaneously adjusted either vertically or horizontally, substantially as herein specified. EFFECTS OF KILN-DRYING- After a long-range investigation of the sub- ject, the Forestry Division of the Agricultural Department at Washington, sums up the evi- dence as to the effects of kiln-drying native woods as follows : Although kiln-drying has become quite uni- versal, opinions are still divided as to its effects upon the strength of the material and other qualities. Many objections and claims as to physical and chemical changes produced by the treatment remain unsubstantiated. The method most widely used and most severely criticised is that of the "blower" kiln, where hot air (180° F.) is forced into the drying room by means of powerful fans. Besides the many, in part, unreasonable and contradictory claims about closing or opening of pores, chemical or physical influence on the sap and its contents, albumen, gum, resin, sugar, etc., substances whose very existence in many cases is problematical or doubtful, the general claims of increased checking and warping, " casehardening," "honeycomb- ing," etc., as well as reduction of strength, are still prevalent even among the very manufactur- ers themselves. The manner and progress of the kiln-drying may render this otherwise useful method of seasoning injurious. Rapid drying of the heavier hard woods of complicated structure, especially in large sizes and from the green state, is apt to produce inordinate checking and thus weakening of the material. Well-constructed "blower kilns,,' where the hot air is blown in at one end and escapes at the other (this latter always the entrance end for the material) are giving satisfaction. The best kiln, however, seems to be one in which ample piping in the kiln itself insures sufficiently high (up to 1800 F.), uniform t
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectforestsandforestry
