DURABILITY. 103 



rersicolor) and Jarrah (E. marginata), and Indian iron- wood, 

 Xi/Un dolabriformis (Pjngado), are used in London. 



Woods wear away most rapidly when their radial or 

 tangential sections are above ; as, however, these sections 

 exhibit the beautiful silver-grain of the wood, they are used 

 for parquets, while in street-paving only the transverse sections 

 are laid uppermost. 



The animals that reduce the durability of wood in 

 buildings and furniture are chiefly insects, which construct 

 passages in wood for laying their eggs and for the development 

 of their young broods. Their presence may be detected by 

 the occurrence of little holes in the wood and the exudation 

 of boring-powder. Among the worst enemies of wood are 

 little beetles and their larva?, such as Auobium tesselatum 

 and A. pertinax (the death-watch) ; Tomicus iincatits (also in 

 living trees) ; Dermextes, chiefly in broadleaved wood; Lime.rt/lon 

 narale, in oak-wood in dockyards. Species of Tetmpiion and 

 Sirc.i: bore into larch and other conifers. In the tropics, and 

 even in Southern Europe, white ants (Termites) are extremely 

 destructive to wood, sparing only very few spec 



Bamboos are very subject to be wormeaten. especially the yearling culms. 

 which ;ire very soft and sappy. Only :? to .~>-year-old culms, which are 

 thoroughly lignified, should bo used as rafters, and these only after several 

 months 1 SOakiDg in a tank, or after being lloated long distances in rafts on a 

 river. The natives of India believe that bamboos felled during bright moon- 

 light nights become wormeaten much more readily than those felled during 

 the dark half of the month when the moon does not shine at night. An 

 experiment was made by the translator at hehra Dun in isxr, to determine 

 this, and Ion bamboos were cut during the bright moonlight and 100 cut 

 during the dark part of the month, and the former were much more wormeaten 

 than the latter. It is probable that certain insects, the larva- of which attack 

 bamboos, tly only during the bright moonlight nights, when they lay eggs in 

 the bamboos. 



Further investigations on this subject were made in .Madras in IS'.IS and 

 subsequent years, and these are described by K. 1*. Stebbing in the Indian 

 Ftn-i'xter, November, liioi;. The insects in question are said to be Dlnoderus 

 pilifntux and I), iii'miita*. The experiments were not conducted scientifically, 

 a'nd Stebbing suggests further experiments to decide this question. 

 E. K. Woakes. in a paper read before the American Institute of Mining 

 Kngineers and printed in the Tn>j>u-al Agriculturalist for October, IS'.)'.!, states 

 that in the Republic of Columbia, in South America, ' not only bamboos, but all 

 timbers, are felled during the waning moon." 



Whenever poles containing only sapwood, or bamboos, are used for rafters, 

 evidently they should be dried thoroughly ; when exposed to smoke, as they 

 are in the roofs of Indian huts, this prevents further danger from insects. 



