TIMBER PHYSICS — SOUTHERN PINE. 347 



from the results that the oft-claimed superiority of the timber of certain localities is not 

 substantiated by experiment, but that there is heavy and strong as well as lighter and weaker 

 timber in every locality throughout the range of these species. The all-important effect of 

 moisture was carefully considered throughout the work, and it was established that in general 

 an increase in strength of at least 50 to 75 per cent takes place during ordinary seasoning, so that 

 for all designing of covered work, as in ordinary architecture, this improvement may be depended 

 upon and considered in the proportioning of the timbers. 



The manner in which the valuable information was secured and communicated will appear 

 from the following reprint of Circulars 12 and 15, issued in 1896 and 1897: 



Southern Pine — Mechanical and Physical Properties, 

 the material under consideration. 



The importance of reliable information regarding the pines of the South is evident from the fact that they furnish 

 the bulk of the hard-pine material used for constructive purposes with an annual cut hardly short of 7,000,000,000 

 feet B. M., which, with the decline of the soft-pine supplies in the North, is bound to increase rapidly. 



Although covering the largest area of coniferous growth in the country (about 230,000 square miles), proper 

 economies in their use are nevertheless most needful, since much of this area is already severely culled and the cut 

 per acre has never been very large. Hence the demonstration (a result of the investigations in this Division) that 

 bled pine is as strong and useful as unbled, and the assurance that long-leaf pine is in the average 25 per cent 

 stronger than it is often supposed to be, and therefore can be used in smaller sizes than customary at present, must 

 be welcome as permitting a saving in forest resources which may readily be estimated at from eight to ten million 

 dollars annually, due to this information. 



The pines under consideration, often but imperfectly distinguished by consumers in name of substance, are : 



(1) The long-leaf pine (Pinus palmt?*is), also known as Georgia or yellow pine, and in England as "pitch 

 pine, 7 ' and by a number of other names, is to be found in a belt of 100 to 150 miles in width along the Atlantic and 

 Gulf coasts from North Carolina to Texas, furnishing over 50 per cent of the pine timber cut in the South — the 

 timber par excellence for heavy construction, but also useful for flooring and in other directions where strength and 

 wearing qualities are required. 



(2) The Cuban pine (Pinus heterophylla), found especially in the southern portions of the long-leaf pine belt, 

 known to woodsmen commonly as "slash pine," but not distinguished in the lumber market. It is usually mixed in 

 with long leaf, which it closely resembles, although it is wider ringed (coarse grained), and to which it is equal if 

 not superior in weight and strength. 



(3) The short-leaf pine (Pinus ecliinata), also known, besides many other names, as yellow pine and as North 

 Carolina pine, but growing through all the Southern States generally north of the long- leaf pine region; much 

 softer and with much more sap wood than the former two, useful mainly for small dimensions and as finishing wood, 

 being about 20 per cent weaker than the long-leaf pine. 



(4) The loblolly or old-field pine (Pinus tceda), of similar although more Southern range than the short leaf, also 

 known as Virginia pine, much used locally and in Washington and Baltimore, destined to find more extensive 

 application. At present largely cut together with short leaf and sold with it as "yellow pine," or North Carolina 

 pine, without distinction, although sometimes far superior, approaching long-leaf pine in strength and general 

 qualities. 



The names in the market are often used interchangeably and the materials in the yard mixed. All four species 

 grow into tall but slender trunks, as a rule not exceeding 30 inches in diameter and 100 feet in height; the bulk of 

 the logs cut at present fall below 20 inches. The sapwood forms in old trees of long leaf (with 2 to 4 inches) about 

 40 per cent of the total log volume; in Cuban, short leaf, and loblolly 60 per cent and over. 



A reliable microscopic distinction of the wood of the four species has not yet been found. As a rule long leaf 

 contains much less sapwood than the other three. The narrow-ringed wood of long leaf (averaging 20 to 25 rings 

 to the inch) usually separates it also from the other three, while the especially broad-ringed Cuban excels usually 

 also by broader summer- wood bands. In the log short leaf and loblolly may usually be recognized as distinguished 

 from the former hy the greater proportion of sapwood and lighter color dne to smaller proportion of summer wood. 

 The general appearance of the wood of all four species is, however, quite similar. The annual rings (grain) are 

 sharply defined; the light yellowish spring wood and the dark orange-brown summer wood of each ring being 

 strongly contrasted produce a pronounced pattern, which, although pleasing, especially in the early forms (which 

 occur occasionally;, may become obtrusive when massed. 



