PRACTICAL ARBORICULTURE 41 



TO WHAT EXTENT MAY THE METALS SUPERSEDE WOODS? 



WRITTEN IN 1882 TWENTY-FOUR YEARS AGO. 



Two factors enter largely into the solution of this question : the exhaus- 

 tion of particular forest products ; its increased cost by reason of scarcity ; 

 and the adaptability of me metals for such purpose. 



The present generation has witnessed the rapid change from wood to steel 

 in ship building. 



The difficulty of obtaining sufficient oak of suitable quality, the rapid dis- 

 appearance of fir and pine on the eastern seaboard, checked the great industry 

 of Maine. The Civil War and piratical cruisers soon cleared the ocean of 

 vessels bearing the American flag and completed the overthrow of ship 

 building in the United States. Great Britain, possessing no extensive forests, 

 but having inexhaustible supplies of coal and iron, was well situated to take 

 advantage of these circumstances and press the construction of steel ships. 

 Since that time, with the recovery of business and increase of manufactures, 

 many of the finest steel ships have been built in American yards, while wood 

 has been relegated to the use of smaller craft. 



Some furniture which was formerly made entirely of wood, is now being 

 replaced by metals, important among which may be mentioned bedsteads, 

 which for sanitary and other reasons, are far better than of wood. 



\Yhile such instances may be noted in the change from timber to metals, 

 yet the employment of iron, steel, brass or other metals for many articles for 

 which the greater quantity of wood is now used, is practically prohibitive, 

 largely on account of the greater expense of the metals. 



In some of the larger cities a portion of the telegraph poles are of iron, 

 but the cost of these far outweighs the cost of wooden poles, even considering 

 their great durability. No doubt these will be employed in the cities to a 

 greater or less extent for experiment or possibly from compulsion, but this is a 

 small proportion of the millions used throughout the country which must be 

 of wood. 



Numbers of experiments have been made of iron and steel for railway 

 ties, and whole books have been written to urge its use and prove its efficiency, 

 but many impediments lie in the way of the adoption of a rigid metal to sus- 

 tain steel rails, which must be frequently removed for replacement or repair. 



Yet the vital objection to iron or steel is the greater cost. 



In a railway tie there must be a broad surface to rest upon the bed, or sub- 

 structure to support the rails and prevent their depression when the immense 



