234 NATURE AND PROPERTIES OF TIMBER. [sect. x.
The colour of sycamore is generally of a brownish white; sometimes of a yellowish white,or nearly white in young wood, with a silky lustre. Its texture is nearly uniform, and theannual rings not very distinct. Its larger septa are small and close, and perhaps it mightbe more correctly described as having distinct smaller septa, and no larger septa. Its flow-ers are small, presenting a minute dappled appearance. The wood is sometimes beautifullycurled. In large trees the wood is generally tainted and brittle. It is in general easy towork, being less hard than beech.
The cohesive force of a square inch varies from 5000 to 10,000 pounds; its modulus ofelasticity is 1,036,000 pounds for a square inch. A cubic foot of sycamore weighs from 34
to 42 pounds when dry.
Representing the strength of oak by 100, that of sycamore is. 81
stiffness of oak by 100,. 59
toughness of oak by 100,. Ill
Evelyn’s Silva: Rondelet, l'Art de Batir.
CLASS II.
382.—The second class contains all woods that have no larger transverse septa. To thisclass many woods belong, and of various colours and qualities.
This class contains three divisions; the first and second formed on the same distinctionsas the first and second in the first class (art. 374); the third division includes all the woodsof which the pores are filled with resinous matter.
DIVISION i.
383.—In the first division of the second class the annual ring is nearly compact towardsone side, and porous towards the other side; and from this inequality the wood is very sub-ject to warp in drying. The author has only described four woods belonging to this divi-sion ; these are the chesnut, the ash, the elm, and the false acacia.