THE OAK. 



429 



neither porous nor ligneous, and from fifteen to 

 twenty lines in thickness. The advantage of 

 this substance for bottle corks is, that it possesses 

 the elasticity necessary to conform exactly to the 

 shape of the neck of the bottle; and also an im- 

 permeability of structure, which prevents the 

 contained liquor from being absorbed, and dissi- 

 pated by evaporation. 



According to Michaux, the cork gathered in 

 France is from 17 to 18,000 quintals, each of 

 which gives from 7,000 to 7500 corks 18 lines 

 long, when the sheet is even and smooth. From 

 110 to 115 millions of corks are annually con- 

 sumed in France. In the year 1827, 2500 tons 

 of cork bark were imported into Great Britain. 

 Besides being made into corks, it is also manu- 

 factured into floats, shoe soles, and other articles. 

 The smoke and charcoal of burning cork col- 

 lected, forms the substance called Spanish black. 



Cork was well known to the ancients. 

 It Is mentioned by Theophrastus, Pliny, and 

 other authors, as in use among the Greeks and 

 Romansforftoats to fishing nets, buoys to anchors, 

 and several other purposes. During the seige 

 of Rome by the Gauls, when Camillus was sent 

 to the capitol through the Tiber, he had a life 

 preserver of cork under his dress. 



The Wliite OaJc (q. alba). This is a native 

 of the United States of America, and of parts 

 of Canada. It rises to the height of seventy or 

 eighty feet, by six or seven feet in diameter. 

 The leaves are of a light green, six or seven inches 

 long, and four broad in the middle: they are 

 regularly indented, almost to the midrib; the 

 indentations are obtuse, the footstalks are short. 

 The acorns very much resemble those of the 

 common oak. The bark is of a grayish-white 

 colour, with large black spots. The timber is 

 of a reddish hue, and in strength and durability 

 much resembles that of the British oak; but it 

 is less heavy and compact. The wood is uni- 

 versally used in America for various purposes in 

 the arts. The bark, which is used for tannin, is 

 also said to produce a purple dye. 



The exports of this wood which come through 

 Quebec, are chiefly from the borders of Lake 

 Champlain, within the limits of the territory of 

 the United States. Though not so durable for 

 ship-building as the British oak, it has the ad- 

 vantage of a superior elasticity, by which it can 

 be bent in a shorter time into ship timber. 



The Red Oak (q. ruhra). This species is 

 found in most parts of the North American con- 

 tinent, but flourishes best in the northern states, 

 and in Canada. It is a tall tree, growing to the 

 height of eighty feet. The bark is smooth, and 

 of a grayish colour, but darker on the young 

 branches. The leaves are six inches long, and 

 two and a half broad in the middle; they are 

 obtusely sinuated, each sinus ending with a 

 bristly point; of a bright green colour, with 



short footstalks. The leaves continue green till 

 late in autumn, and if frost does not set in early, 

 even to Christmas, before which time they change 

 their colour to a red. The acorns are very abun- 

 dant, large, and contidned in very flat cups. The 

 timber is reddish, its texture coarse, and its pores 

 entirely empty; they are sometimes large enough 

 to admit the introduction of a hair. The wood 

 is strong, but is apt to decay soon. It is chiefly 

 used for staves. The bark is also employed in 

 tanning. 



Chestnut Oak (q. prhms). Michaux enum- 

 erates five species of the chestnut oak. They 

 are so called because the leaves resemble very 

 closely those of the chestnut tree. The largest 

 sort grows in the rich low lands, and attains a 

 considerable height. The wood is small grained, 

 and very serviceable in the arts: the bark is gray 

 and scaly, the leaves six inches long, and two 

 broad, indented on the edges with numerous 

 transverse veins proceeding from the midrib to 

 the margin. They are of a bright green hue. 

 The acorns are large, with short cups. The 

 species are — 



The swamp wliite oak, discolor. 

 Chestnut white oak, palustris. 

 Rock chestnut oak, monlicula. 

 Yellow oak, acuminata. 

 Small chestnut oak, chncapin. 



These oaks are found partially diffused over tho 

 middle and northern states ot America. 



The Live Oak (q. virensj. This species is 

 found exclusively in the maritime parts of the 



Live Oak. 



southern states of Florida, and lower Louisiana. 

 The influence of the sea air seems necessary to 

 its existence; for it is seldom seen to make a part 

 of the forests even at so short a distance as fif- 

 teen or twenty miles from the shore. It is most 

 abundant on the islands, and around the bays 

 of the main land. The most common height of 

 this oak is from forty to forty-five feet, with a 

 diameter of from one to two feet. Like all solitary 

 growing trees, this one has a very broad tufted 

 head, borne upon a trunk eighteen or twenty 

 feet high, but which most frequently branches 

 out into sevenJ boughs at about half that height; 



