286 ON THE SOILS AND SUBSOILS 



felled in order to make way for the cultivation of cereals and 

 other agricultural produce, while sufticient energy has not been 

 displayed in its reproduction. Thus the noblest of our forest 

 trees is now chiefly found in hilly districts. . On account of the 

 diminishing supply, and rising demand for oak timber, much has 

 been done of late, both at home and abroad, for its cultivation. 



Young trees shelter the soil from the sun, but as they advance 

 they demand more light and room, so that many die if not 

 timeously thinned by the axe. Among hardwoods, the oak, ash, 

 maple, sycamore, and elm, and among conifers, the Scotch fir, 

 Austrian pine, Weymouth pine, and larch are of this order. 

 Such trees, excepting the pines, are not so well suited for unmixed 

 timber forests, and are best developed singly or in groups in 

 high timber forests of other trees. In such forests the oak 

 assumes greater dimensions than when growing only with other 

 oaks, for it may be laid down as a rule that it thrives lest with 

 the croivn free, the stem sheltered and in shade, and the foot under 

 covering (German — Freie krone, seitenshiitz, bodendecke). 



We shall now point out the differences of the two varieties of 

 oak in regard to the situations in which they shew the most 

 favourable growth, and most frequently occur. 



Qucrcus i^edunculata is disposed to develop many branches, 

 but where this is not possible (as in forests of beech with oak), the 

 stem is straight, often free from branches to the height of 70 or 

 80 feet, its whole length reaching 100 to 130 feet. The tap-root 

 goes to a depth of 5 to 6 feet in good soil, so that the subsoil is 

 of great importance in its growth, and for the quality of the 

 timber. Moderately cleft, tilted (but not horizontal) varieties of 

 limestone, of the milder clay slates, and of the richer sandstones 

 and marls, of granite, basalt, and diabas, and clayey porphyry, 

 and of good peat — all of which generally continue fresh, and are 

 not apt to collect an over supply of water, — are by far the most 

 favourable subsoils for both kinds of oak. 



The timber is of fine texture, tough, hard, and heavy. Q. 

 jyednneulata yields the strongest and most durable timber grown 

 in large quantities in our climate, and is indispensable in ship- 

 building, in the construction of mills, and of structures in or 

 near water ie.g,, the chain pier at Trinity). Under water it is 

 imperishable, becoming at last petrified. 



Q. scssiliflora is in many respects similar to Q. indunculata. 

 It does not grow so quickly, but has a longer life. It is more 

 disposed to form branches, but may, under favourable circum- 

 stances, attain equal proportions. The roots do not penetrate 

 so deep into the soil. The timber is less tough and elastic, but 

 more easily cleft, hence more prized by coopers. The textm-e 

 being coarser, it is not so well suited for carving and the manu- 

 facture of cabinets. It is heavier, and yields better firewood (in 



