1885.] VNITKD STATES CENSUS FORESTRY REPORT. 445 



temperature are given in this introduction, witli lists of the generic 

 and specific distributions. Tart 1 follows, comprising 200 pages, 

 and embraces a catalogue of North American forest trees, with 

 remarks upon their synonymy, bibliographical history, distribution, 

 economic value and uses. A feature of high value to this catalogue 

 is the bibliograpliical references to the history of the species ; and 

 in many instances no less than seventy-five references are given to 

 authorities wherein the species is described, together with citations 

 to volumes in which figures and illustrations of the same occur. 

 Four hundred and twelve species are described, and an index to 

 this first part comprises twenty-four double-colunni pages in fine 

 type. 



Part 2 comprises the results of a critical examination of the 

 woods of the United States, to determine (1) the fuel value of the 

 woods ; and (2) their value as material for construction. This 

 portion of the volume extends to about 150 pages; and very 

 elaborate tables are given as follows : — I. Specific gravity, ash, and 

 weight per cubic foot of dry specimens of four hundred and twelve 

 species of wood. The thorough character of the work embodied in 

 this table may be gathered from the following items of examination : 

 {a) State from wlience the specimen was obtained ; {h) locality in 

 the State where obtained ; (c) name of person collecting the speci- 

 men ; {d) character of soil on which it grew ; (t) diameter of tree 

 in meters; (/) layers of growth of heart wood and sap wood ; ijj) 

 specific gravity determinations (three examinations each, and an 

 average) ; (A) ash determinations (two examinations and an average) ; 

 (i) weight per cubic foot in pounds ; (A) remarks. II. Actual 

 fuel value of some of the more important woods of the United States ; 

 embracing botanic and common name of species ; place whence 

 obtained ; fuel value per cubic decimeter and per kilogram ; relative 

 fuel value by volume and weight ; percentages in the dry wood of 

 ash, hydrogen, carbon, oxygen, hydrogen combined with oxygen, 

 excess of hydrogen ; specific gravity, and weight of cubic fuut in 

 pounds. III. Behaviour of the principal woods of the United 

 States under transverse strain — comprehending name of species ; 

 state and locality whence obtained ; name of collector ; character 

 of soil in which specimen grew ; specific gravity of the air- 

 dried specimen ; a neat diagram showing direction of grain 

 for each specimen ; coefficient of elasticity in the first and 

 second defections ; defection in millimeters, under a pressure 

 in kilograms, of 50, 100, 150, 200; (set); 200, 250, 

 300, 350, 400, 450, 500, 550 ; ultimate strength (transverse 

 pressure) ; remarks. This table embraces an examination of four 

 hundred and five species. IV. Behaviour of some of the woods of 



