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The life of joists is given at twenty years, and of girders at twenty-five years. We were informed of a girder twenty-six years in a bridge, and still quite sound (Dingo Creek, Belbourie, near Wingham).
The life of rails of a chock and log fence is given at thirty-five years. Several witnesses give the life of rails at twenty years, others thirty years, others "fences" (? rails) at forty and more. One correspondent gires the lives of "posts" at forty years.
Shingles are stated to last thirty years. Turning to ship-building, the planking, beams, &c., of a pilot steamer after nineteen years wear were stated to be “as sound as ever." At the London Exhibition of 1862, a piece of timber was shown from the hull of the steamer “ William the Fourth,' and properly certified. With the exception of some slight charring on the mere surface of the timber in the immediate vicinity of the boilers, the entire fabric of this vessel is as substantial and sound as when she was built in the year 1830 (thirty-one years' wear).
If the above statements as to the life of spotted gum be examined (and reference to the evidence will show that other instances of long life of the timber can be quoted) no doubt can remain that, under the circumstances alluded to, spotted gum is a very durable timber,-in fact, that it is one of the most durable of our timbers for the purposes stated.
2. Strength, toughness, and elasticity. We have already dealt with this in speaking of the fitness of spotted gum for coach-builders' purposes, &c.
3. Capacity for bending. This is readily admitted, and advantage is taken of this property, which spotted gum possesses in a high degree, by the coach-builder.
4. Lightness. This is also a great advantage for light vehicles. Throughout the Western district the coach-builders purchase, at great expense, for cartage and railway freight, spotted gum for buggy and waggon building, no other arailable timber having the same elasticity and toughness.
5. Easy working. It gives a clean face, takes paint readily, and when at all seasoned before putting in work, does rot warp or twist, particularly in buggy shafts and poles.
6. Evenness of quality. This is an important question, all timber showing large gum-veins (or discoloured in appearance), or carrying any sap whatever, should be rejected. Timber must be cut from fully-matured trees, absolutely free from heart or heart-shakes and sap. Shipments should be uniform in colour, from one district, if possible, and as free from veins as possible. For home railway waggon sizes it should be specially selected. We feel confident if this is done it will at once command the attention of English engineers.
7. Large sizes readily oblainable. This is borne out by the heights and girths given by various correspondents in reply to Question 19.
8. Comparative freedom from pipe. This is more particularly applicable to Southern spotted gum, and we do not know that it can be altogether considered to be an advantage. Freedom from pipe means presence of heart, inferior timber in regard to which special care ia, or should be, taken to remove.
We do not recommend it for squared girders, as it shells in squared sizes under sun exposure.
(6.) DISADVANTAGES (AS STATED BY TARIOUS CORRESPONDENTS.)
1. Liability to warp and twist.
1. Liability to warp and twist (irregular shrinking). If the timber is cut when the sap is down and allowed to season without erposure to the sun, it shrinks evenly; but if exposed to sun, and cut full of sap in small sizes, free of heart, it twists from the heart out, thus,
Opinions are nearly equally divided, but the balance of opinion is in favour of spotted gum not shrinking more than colonial hardwoods usually do.
2. Inclination to split. It does not split any more than blackbutt, and not as much as Sydney blue gum (E. saligna). We think that increased attention should be given to the proper period for felling spotted gum, i.e., it should be cut when the sap is up
3. Liability to attack by White Ants. Diversity of opinion exists in regard to this, but we are of opinion the durability of spotted gum is equal to that of the average colonial timbers as regards white ants, and superior to that of ironbark and blackbutt, to which they are very partial.
4. Great thickness of worthless Sapwood. The sapwood of spotted gum decays most rapidly of all the sapwoods of the best timbers, and perhaps even of those of all hardwoods whatsoever. It is utterly worthless, and has contributed a good deal to the prejudice which exists in some quarters in regard to spotted gum. The sapwood should be removed with the greatest care. The sapwood readily crumbles to a fine powder through the operations of the larvæ of a small beetle (Lyctus brunneus), but these insects confine their attention to the sapwood. Because of the similarity of the sap to the other part of the timber, and because of the worthlessness of the former, the inspection of spotted gum demands especial care on the part of the inspector of timber. . We consider that it is especially unsuited for telegraph poles and piles, inasmuch as saplings of the size required for such purposes carry an inordinate proportion of sapwood, which is of a peculiarly perishable nature.
Spotted gum should be cut from mature trees, and should be free from sap and heart-wood. It also should be well seasoned.
5. Presence of Gum-veins. The timber is often deteriorated by the presence of gum-veins, and we recommend the timber to be “as free of gum-veins as can be procured."
Minimum girth for felling. The regulations of the Forest Department preclude the cutting of spotted gum trees less than 6 feet in girth, measured 5 feet from the ground.
In our opinion this regulation concerning minimum girth should be strictly
Distribution of Spotted Gum. There is no doubt that it varies according to soil and situation—that occurring on flats near the sea-level being faulty and of inferior durability, while that obtained from ridges and sides of mountains a few miles inland is altogether different in quality. It is best on poor soils—ridges in barren country. It extends from the Bega River north to Queensland, and westerly as far as the Dividing Range.
We have indicated by the letters N and S whether a locality is north or south of Sydney. It is a moot point whether the best spotted gum comes from north or south of Sydney, and we are not in possession of sufficient data to settle the matter, even if there were any practical advantage in doing so. We are in possession of evidence that spotted gum timber of the highest class is produced both south and north of Sydney.
We took the opportunity of asking question 21, in framing the series, in order to make them complete. One reply gives some account of the skin. irritation caused, and we simply draw attention to the subject in the expect. ation that medical men may, when they bare suitable opportunity, describe this trifling (but, we are assured, very annoying) skin complaint in scientific language.
J. H, MAIDEN
G. S. COWDERY. 14th February, 1896.
J. V. DE COQUE.
SPOTTED GUM.-SCHEDULE OF QUESTIONS. 1. Have you used Spotted Gum timber on any work on which you have been engaged ! 2. What is the nature of the work?
3. If on bridge work, culverts, flood-openings, or wharfs, state the situation in which the timber was placed, its size, and whether it is or was in contact with the earth, water, or otherwise, and the locality of the work.
4. Can you inform us, of your knowledge, as to the length of time that Spotted Gum has been used in such works .
5. State for what purpose you consider this timber best suited.
6. State the locality, if possible, in which the timber referred to in the previous questions was grown.
7. Have you ever used Spotted Gum for planking, decking, or wood-paving? With what results ?
8. Does your experience indicate that Spotted Gum shrinks more than colonial hardwoods usually do?
9. Does the sapwood and heart of Spotted Gum decay more quickly than those of other 10. What is the durability of Spotted Gum as regards white ants ?
11. What, in your opinion, are the chief advantages or disadvantages to the use of Spotted Gum?
12. What is Spotted Gum used for in your district ? 13. Have you experience of the use of Spotted Gum for fence or telegraph posts, piles, or other work in the ground not previously specifically alluded to ?
14. Please state, if possible, the locality from which the Spotted Gum, to which you refer in any of your answers, was obtained.
13. Is Spotted Gum growing in your district ? What is your opinion of the merits of Spotted Gum from that locality?
16. Wbere, in your opinion, does the best Spotted Gum come from?
17. In what parts of the Colony does Spotted Gum grow, in what relative abundance, and what soil and situation does it prefer?
18. Does it vary in quality according to soil and situation ? 19. Give the average size-height to first limb, and girth 3 feet up. 20. What, in your opinion, should the minimum of girth for cutting be? 21. In parts of Queensland timber-getters and sawyers who handle Spotted Gum are sometimes affected with a rash called “Spotted Gum rash.” Do you know any district in which this skin complaint prevails, and can you furnish any particulars in regard to it?
22. Any other remarks?
WHEAT-THRESHING is a matter of interest both to the wheat grower and the thresher; accordingly, in 1893, I began making notes on the ease or difficulty with which the different varieties of wheats were threshed.
The method adopted to secure these notes was extremely simple, yet perfectly effective.
The test applied to each variety annually was as follows:
Put a given quantity of heads into a bag. Beat these heads a certain number of blows in a uniform manner. When the beaten heads are emptied out it is easy to decide whether the wheat will thresh easily or with difficulty.
The results do not show the exact difficulty or ease with which a variety of wheat is threshed ; in other words, do not show the exact cost of threshing out (say) 100 bushels, but they do show the relative difficulty or ease, or cost with which the varieties may be threshed.
In the crop of 1893 only thirty-six wheats were tested in this way, but in the crop of 1891 four hundred sixty varieties were tested, while in 1895 and 1896 nearly one thousand samples were tested. I have thus arrived at definite conclusions based on a large number of tests and on observations extending over several years.
The ease or difficulty with which a wheat can be threshed is determined by the nature of the chaff,—the same factors that cause shelling in the field, or the reverse, also causing differences in the threshing. Sometimes the chaff is thick and tough, and clings closely to the grain ; then the wheat threshes with difficulty. Again, the cbaff may be weak, or, even if in itself strong, may have a weak and brittle attachment; then the wheat threshes easily. The weather has a great influence on threshing, damp weather being unfavourable and dry weather favourable.
In some seasons wheats which usually thresh easily become much less easy to thresh. Thus, the dry season of 1895-6 caused the wheat grown in the Riverina district to thresh with much greater difficulty than usual. In that harvest it was noticed that Steinwedel, a wheat that usually shells badly in the field and threshes with great ease, did not shell much, and was by no means very easy to thresh. On the other hand, wheats that are usually hard to thresh, may become, through the peculiarity of the season, easy to thresh.
It is needless to add that stripping is in most respects analogous to threshing, and that in the preceding paragraphs the words "threshes" and "threshing" can be replaced by the words “strips” and “stripping"; in fact, it is only when we consider the extent to which Australian wheat is stripped that we get a correct idea of the value of accurate data in regard to threshing.
It is true that the most desirable degree of ease in threshing is a matter of individual opinion. One grower, with a large and smart team, and faultless machinery run night and day, may prefer to grow wheat that strips or threshes