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There are twenty-eight ur thirty speL-iea of birdies uow recognized 

 in the world, thirteen of which are found in America. Ten of the 

 latter are trees but only six of them are of commercial importance. 

 The birch tree is widely distributed from the Arctic circle to Texas 

 in the new world, and to southern Europe, the Himalayas, China and 

 Japan in the old world, some species forming great forests at the 

 north, or covering high mountain slopes. A very common shade 

 tree in the eastern part of this country is the exotic species of white 

 birch (Betiila alba), and a varietal form with slender drooping 

 branches and cut leaves. The six native species of chief importance 

 are sweet, black or cherry birch, yellow 

 birch, paper or canoe birch, gray or white 

 birch, river or red birch, and western birch. 



The following table will afford a fair idea 

 of the sizes of the mature trees and the 

 average weights and densities of their 

 woods: 



as 



a| 



°s 



Sweet . . . 

 Yellow . . . 

 Paper .... 



Gra.T 1 



Kiver ' 1' 



Western " 



The wood of the birches has very numer- 

 ous small pores scattered throughout the 

 growth ring, though somewhat less abundant 

 in the summerwood than in that formed 

 earlier in the season; they are mostly in- 

 distinct without a lens. There are no con- 

 spicuously broad rays, such as found in 

 sycamore and beech, but in sweet and yel- 

 low birch some of them are large enough to 

 show quite plainly on quarter-sawed mate- 

 rial. The w^ood, on the whole, is straight- 

 grained, splits without difiSculty and is easy i 

 to work. There is considerable variation 

 in color between different species, sweet and 

 yellow birch having rather dark heartwood ; 

 paper, gray and western very light colored 

 or almost white; and the river birch some-- 

 what intermediate. In the w-hite birches it 

 is very common to find abundant small 

 brown patches (cross section) or stripes 

 known as pith ilecks, 



CROSS SECTION OF 



GROWTH RINGS 



MAGNIFIED 



(longitudinal sections) 

 These are the result of the tunneling of the 

 larvffi of small moths and possibly of other insects. 



The demand for birch wood has increased rapidly during the past 

 ten years. According to the census returns the output in 1910 

 more than tripled that of 1899. The total quantity was nearly 

 421,000,000 feet, cut by 3,703 mills, located in thirty-two states, 

 ranging as far south as Georgia and Texas and as far west as 

 Washington. Wisconsin has led in tlie cut of bin-h hunber for 

 several years and, with Xew Hampshire, reported an increased pro- 

 duction in 1910. Wisconsin supplied in 1910 over forty-four i>er cent 

 of the cut; the New England states contributed a little over twenty- 

 five per cent. No distinction of species is made in tliese returns. 



Birch has not been used to any considerable extent for tight cooji- 

 erage though occasionally employed for half-barrels. The revision 

 committee of the Chicago Board of Trade has issued a revised list 

 of woods for the packing house trade and as birch is included it will 

 probably become important in that class of tight cooperage. In the 

 report of the woods used in tight cooperage in Canada birch is 

 credited with 105,000 staves out of a total of 7,137,000. For slack 

 cooperage in this country, birch ranked seventh in 1910, with a total 

 of 61,438,000 staves and 3,131,000 sets of heading. In Canada the 



—32— 



luunber of staves was 2,705,000, heading 486,000 sets, hoops 986,000. 

 In the manufacture of veneer the amount of birch consumed was 

 27,633,000 feet, log scale, in 1910, a very considerable increase over 

 ]ireeoding years. In 1908, for example, the total amount was some 

 ID.OOO.OOO feet less. Most of this may be classed as utility veneer, 

 tliough considerable of it was for furniture, cabinet work and inte- 

 rior trim. 



Birch is one of the three principal hardwoods used iu destructive 

 distillation. Charcoal, crude wood alcohol and gray acetate of 

 lime are the leading products. The total amount of beech, birch and 

 maple consumed for purposes of distilla- 

 tion in 1910 was over 1,250,000 cords, but 

 no figures are available as to the propor- 

 tion of birch. From the bark of the sweet 

 birch an oil with wintergreen flavor is ob- 

 tained, which is used for flavoring purposes. 

 The wood of none of the birches is dura- 

 ble in contact with the soil. The use of 

 j)reservative treatment, however, is bringing 

 the wood into common use for railway ties. 

 It is strong enough to resist wear and its 

 structure is suited to ready impregnation. 

 The latter is of particular importance, as it 

 lessens materially the expense of treatment. 

 Sweet, black or cherry birch (Betida 

 lenta) is a common tree of the central 

 hardwoods region, being widely distributed. 

 It attains its greatest dimensions on the 

 western slopes of the southern Appalachians. 

 The wood is the hardest and heaviest of 

 the birches, is very strong, takes a high 

 polish, has a high satiny luster, stains well 

 and is often called mahogany birch. The 

 texture and grain are even and fine and the 

 wood works with ease. Specimens with wavy 

 and curly grain are not uncommon and have 

 a high value for cabinet work. The wood 

 is readily cleavable and is liable to split in 

 nailing. 



It is not always easy to distinguish this 

 wood from that of the yellow birch. Upon 

 comparison, however, it will be found that 

 sweet birch has somewhat heavier, harder 

 and stronger wood. The pores are larger 

 and the rays are wider and more conspicu- 

 ous. The color is brown tinged with red, often deep and handsome. 

 It is unusual to find specimens marred with pith flecks. The bark is 

 like that of cherry and when a bit of it is present on a waney board 

 identification is made very easy 



Sweet birch is one of the most important furniture woods of the 

 United States and when properly stained makes one of the best imi- 

 tations of mahogany of any native wood. It has largely taken the 

 place of cherry because it is cheaper. For example, the furniture 

 factories of Maryland use annually upward of a million feet of 

 sweet birch, worth $26 per thousand at the mill, and ouly 6,500 feet 

 of cherry, costing $73 per thousand. It is extensively employed in all 

 kinds of furniture and cabinet work, frequently in combination with 

 mahogany. It also makes good flooring and interior finish as well as 

 the numerous other uses to which the birches as a group are put. 



Yellow or red birch (Betula lutea) derives its name fronj tlie 

 color of its bark. It is one of the largest hardwood trees of north- 

 eastern America, is very abundant and of its largest size in the east- 

 ern provinces of Canada and in northern New York and New Eng- 

 land, being small and uncommon in southern New England and 

 southward. It is a valuable tree of the Lake States. 



The wood is structurally much like sweet birch, but is finer 

 textured. The pores, which are moderately abundant, are smaller and 



PORTIONS OF TREE 

 OF SWEET BIRCH. 

 FIFTY TIMES 



