. Cyclopedia of architecture, carpentry, and building; a general reference work ... f a piece of timberto another and can even be carried from one piece of timber to an-other by contact. Heartshake. As indicated by the name, heartshake is a defectwhich shows itself at the heart of the tree in the center of the appearance of a cross section of a log affected by heartshakeis shown in Fig. 4. There is first a smallcavity at the center caused by decay, andflaws or cracks extend from this cavityoutward toward the bark. The heart-shake is most often found in those treeswhich are old, rathe
. Cyclopedia of architecture, carpentry, and building; a general reference work ... f a piece of timberto another and can even be carried from one piece of timber to an-other by contact. Heartshake. As indicated by the name, heartshake is a defectwhich shows itself at the heart of the tree in the center of the appearance of a cross section of a log affected by heartshakeis shown in Fig. 4. There is first a smallcavity at the center caused by decay, andflaws or cracks extend from this cavityoutward toward the bark. The heart-shake is most often found in those treeswhich are old, rather than in young, vig-orous saplings; it is especially to be fearedin hemlock timber. Windshake. The defect known as awindshake is so-called on account ofthe belief that it is caused by the rack-ing and wrenching to which the growing tree is subjected by high winds. It is also claimed that it isproduced by the expansion of the sapwood which causes a sep-arationof the annual rings from each other, thus leaving a hollowspace in the body of the trunk and following around between two. Fig. 5. Section of Log ShowingWindshake 19 10 CARPENTRY of the annual rings. , Fig. 5 shows the appearance of a windshakeon the cross section of a log, and this appearance has given rise tothe term cupshake which is sometimes used instead of hollow space may extend for a considerable distance up thetrunk of the tree. Windshakes are very frequently found in pinetimber. Starshake. A starshake is not readily distinguished from aheartshake, as the appearance of a log of wood affected by one isvery similar to that of a log affected by the other, but the differencebetween the two is that while the center of a log affected by a heart-shake is decayed so as to leave a large round cavity at this point, alog affected by a starshake shows no such decay at the center, butthe cracks forming the star extend right across the cross section ofthe log, becoming wider as they approach the center and narrowi
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