^ 



THE WOODS OF THE UNITED STATES. 



A critical examination of the wood produced by the indigenous trees of North America, exclusive of Mexico, 

 has been matle in connection with the investigation of the forest wealth of the United States. 



Mr. S. P. Sharpies, special agent in charge of this department of the investigation, has had general direction 

 of such experiments, and suggested the methods adopted for their execution. 



The object of this examination has been to determine, first, the fuel value of the woods of the United States ; 

 Becond, the value as material for construction of the wood of the principal timber trees of the country. The 

 results thus obtained are highly suggestive; they must not, however, be considered conclusive, but rather valuable 

 as indicating what lines of research should be followed in a more thorough study of this subject. 



The fuel value has been obtained by a determination of the specific gravity and the ash of the absolutely dry 

 wood, supplemented by a determination of the actual chemical composition of the wood of some of the most 

 important trees ; the value of our woods for construction has been obtained by experiments made with the United 

 States testing-machine at the Watertown arsenal. Each specimen as received was at once numbered, and this 

 number, designated in the following tables as "OflBce number", was carefully repeated on every fragment cut from 

 the original tree, and always refers to the same specimen. In a few cases in the early part of the work a 

 sub-number was used to designate a specimen from another tree of the same species received from the same 

 collector. In most cases the specimens were taken from the butt-cut of the tree, and unless it is otherwise 

 mentioned in the remarks, were free from sap and knots; they may be regarded as representing the best wood 

 that could be obtained from the tree. 



The specimens used in the different series of experiments are deposited in the National Museum at Washington 

 and in the museum of the Arboretum of Harvard College. It was found necessary, in order to secure proper 

 material upon which to carry out the various experiments, to obtain a much larger amount of wood of the different 

 species than was actually consumed in the experiments. This surplus material has been worked into 12,961 

 museum specimens, of convenient size, showing as far as possible the bark, sap-, and heart-wood of each species. 

 These have been made into sixty sets, more or less complete, and distributed to the following educational 

 institutions in the United States and Europe: 



Institute of Technology, Boston, Massachusetts. 



United States Military Academy, West Point, New York. 



Academy of Natural Science, Philadelphia, Pennsylvania. 



United States Naval Academy, Annapolis, Maryland. 



SheflBeld Scientific School, New Haven, Connecticut. 



School of Mines, Columbia College, New York, New York. 



National School of Forestry, Nancy, France. 



Museum of Science and Art, Edinburgh, Scotland. 



Agricultural Museum, Rome, Italy. 



Brown University, Providence, Ehode Island. 



Itensselaer Polytechnic Institute, Troy, New York. 



Lawrence Scientific School, Cambridge, Massachusetts. 



Iowa Agricultural College, Ames, Iowa. 



Administration of National Forests, Lisbon, Portugal. 



National Forest Administration, Paris, France. 



McGill University, Montreal, Canada. 



Royal Botanic Gardens, Sydney, New South Wales. 



State Agricultural College, Lansing, Michigan. 



247 



