Page:A primer of forestry, with illustrations of the principal forest trees of Western Australia.djvu/48

42 1.—JARRAH (Eucalyptus marginata).

This is the principal timber tree of the State. Owing to its resemblance to a Honduras timber, in the early days it was called mahogany, but about 1860, as it was realised that this was a better timber and that it has so many fine qualities as to deserve a name of its own, the tree was given its aboriginal name of Jarrah.

Attaining a height of from 100 to 120 feet, the tree has a bole of about half this amount, and a diameter of six feet. The bark, which is furrowed and flaky, but which can be stripped off in long pieces, is rough, fibrous, and in colour dark grey. The flowers are of a yellowish-white. In accordance with an identifying characteristic of all Eucalyptus trees, when the flowers wither the calyx (i.e., the basal portion, as opposed to the coloured portion, the filaments) remains and forms the fruit. In the case of the Jarrah, the fruit or persistent calyx is half-inch in diameter, and almost globular, but slightly flattened on the top with a broad rim or ring. Inside this ring is the ovary, which opens when the seeds are ripe.

A hard wood, but easily worked, and therefore used for almost every purpose. It is strong enough to be used for beams, and its colour and texture are such that it is daily becoming more and more prominent as a cabinet wood. One of its remarkable qualities is its durability when exposed to the worst conditions. The timbering in the first houses built when the Colony was established is still sound to-day, and the post-and-rail fences erected by the earliest settlers are still standing. Its extraordinary durability has, however, rather cheapened it in the eyes of the outside world, where it has commanded a readier sale as a sleeper or paving block wood than for purposes where most expensive wood is generally used. It is to be regretted that the exploitation of the jarrah forests has been conducted practically solely for the sleeper market. Since 1836, the export of timber from the State amounted to 3,992,997 loads, valued at £16,199,342, the bulk of which consisted of jarrah.

It is on Lloyd's list of shipbuilding woods, and jarrah ships in the early days plied between "Western Australia, India, and other parts of the world. Its durability has made it renowned for bridge, wharf, and harbour work, while the telegraph service of the State is dependent upon supplies of jarrah poles.

It is to be found scattered throughout the South-West over some 13,000,000 acres of country within the 25 to 45mm, rainfall belt. The main belt of timber, however, stretches from Chidlow in the North, along the Darling Range to the extreme South of the State, in the neighbourhood of Albany. The total area of prime jarrah forests is probably not more than 2,500,000 acres, and is all on this laterite-capped range of hills.

It regenerates itself well, but the constant firing of forests has resulted in the destruction of the young growth in many parts of the forests. The recovery in milling operations is from 35 to 45 per cent, of the round log.