REVIEWS o i 3 



In the present stands of native growtli it is possible to cut 176 props 

 per acre, while the mines require 573 props to the acre mined. The 

 disproportion is largely due to the size of the timber; it does not pay 

 to use the larger sizes, which must be cut to size. In the regenerated 

 stands relatively even-aged the output of props "could be increased at 

 least 100 per cent." "The ideal forest for use in connection with the 

 coal-mining industry is an even-aged stand of trees of pole size, such 

 as ordinarily can be raised in a period of about 30 to 50 years." 



"There is no question that the regeneration of the forests of eastern 

 Kentucky is a certainty, providing only that adequate protection is 

 given against fire and grazing." This refers to coppice as well as seed- 

 ling growth of broadleaf species. Shortleaf pine also readily repro- 

 duces itself and "can be easily managed in 25 to 30 vear rotation." 



B. E. F. 



The Preservation of Wood. By A. J. Wallis-Tayler. D. Van Nos- 

 trand Co. New York. 



In this book there is a chapter on the "Seasoning or Drying of Wood" 

 which is worth reading for any one making a study of this subject. It 

 is of chief interest in giving a brief resume of the methods of kiln-dry- 

 ing, past and present, used on the Continent. The book is evidently an 

 English publication and without date, but was written subsequent to 

 1914, according to material quoted therein. No reference is made to 

 American dry-kilns. The Sturtevant three-duct kiln, the Wells pro- 

 gressive forced-draft kiln, and the natural draft Erith's progressive 

 drier are described in considerable detail, all of which are English 

 makes. Early designs and patents are briefly described — one in 1837, 

 by De Mecquenem, in which heated air is forced into the drying cham- 

 ber near the floor and escapes near the roof. Methods of soaking in 

 fresh and salt water, of treatment to pressure steam in closed cylinders, 

 drying in smoke, treatment in ozone, replacement of sap by boro-resi- 

 nate of soda by means of an electric current (the Nodon-Bretonneau 

 process), and the charring or scorching of wood are touched upon, but 

 not fully discussed. The information, though very incomplete, is per- 

 haps the best which has been written on this subject as touching the 

 English conditions. H. D. T. 



