572 



THE POPULAR SCIENCE MONTHLY. 



part of the paint which it does not decom- 

 pose. All of the best anti-fouling paints 

 depend for their efficacy on some compound 

 of mercury or copper, while the action of 

 iron is very strong in contact with both these 

 metals ; hence perfect isolation of the paint 

 from the iron is necessary to make them of 

 any value. Besides paints of magnesia and 

 alumina, spirit and benzoline varnishes, 

 powdered coke, anthracite or coal, lime, ce- 

 ment, and various kinds of silicates, mixed 

 or suspended in oils, have been found good 

 in greater or less degrees for these purposes- 

 Zinc oxide also has some slight merits, while 

 red lead paint, which has been used, is " out 

 of the question. It is bound to give out 

 after a certain time ; and, besides, the metal 

 beneath is corroded." 



The Teak-Tree and its Timber. The 



teak-tree is found growing in various places 

 in the East Indies, through a region reaching 

 from the eighth degree of south latitude in 

 Java to about the Tropic of Cancer, and 

 of undefined extent in longitude, but not 

 farther west than 72 east. Its vertical habi- 

 tat is about 3,000 feet above the level of 

 the sea, but seldom below 2,000 feet. Its 

 northern limit is in Bundelcund, where it 

 is found in specimens not tall, at elevations 

 rising as high as 4,000 feet. It grows in 

 groups, a circumstance which is very con- 

 venient in trade. The wood is held in the 

 highest esteem by ship-builders, and is pre- 

 ferred to any other for the backing of iron- 

 clad vessels. It shrinks hardly any, is 

 considered the strongest and most durable 

 timber of India, or perhaps of the world, 

 and resists the attacks of white ants. The 

 qualities of the timber vary greatly accord- 

 ing to the character of the soil on which it 

 grows, sometimes so much as to induce the 

 belief in different species ; but close exam- 

 ination has shown that, though varieties 

 may exist, there is but one species. In 

 Java, the Government have control of 1,- 

 650,000 acres of teak, besides new planta- 

 tions. The planting and raising the trees, 

 and mode of felling, classing, and measuring 

 the timber are carefully regulated. Forest 

 reserves of considerable extent exist in va- 

 rious parts of India, from some of which 

 specimens have been shown more than 100 

 feet lorn', and 93 and 100 inches in cir- 



cumference at the base. One of the chief 

 sources of supply is British Burmah, where 

 the total area of the reserve forests is 3,2*74 

 square miles, and 836 square miles were 

 added during 1881-82. Nineteen thousand 

 teak-trees were girdled, and 130,000 tons 

 or 6,500,000 cubic feet of the timber were 

 exported during this year from Rangoon 

 and Maulmain. The principal forests are 

 near the Irrawaddy River, where water con- 

 veyance is easy and ship-building is pros- 

 perous. A very fine plantation has been 

 established at Nilambur, on the river Bey- 

 pore, in Malabar, where 100 acres are 

 planted each year, and there are now about 

 1,800,000 trees. An increasing source of 

 supply is also being developed in Siam. 

 According to Colonel Beddome, the growth 

 of teak is very rapid, compared to that of 

 the oak. The growth in the sapling state 

 may be calculated at about one or two cubic 

 feet a year ; but after thirty years it is im- 

 mensely accelerated, and an increase of five 

 cubic feet has sometimes been remarked in 

 a year. Several other trees, but little known 

 as yet, are mentioned as nearly equal in 

 value to the teak. The takieng, besides be- 

 ing a rival to it in size and quality, pos- 

 sesses the advantage of being easily bent 

 by artificial means. Sir Robert Schom- 

 burgk saw a log of it measuring 135 feet, 

 perfectly sound, in the building-sheds of 

 the King of Siam. The red peema of Bur- 

 mah and Tenasserim is considered equally 

 useful with teak, as is also the touk-kyan, 

 with its dark-brown wood. Angely is well 

 suited for the floors and bottom-planking of 

 ships, but has to be used with copper, as it 

 corrodes iron. Jackwood, a tree of the 

 same family (Artocarpus), furnishes an ex- 

 cellent fancy and furniture wood, and is 

 admirably adapted for boat-building. An 

 Australian timber called tuart is believed by 

 Mr. Simpson to be superior to all others for 

 the backing of armor-plated vessels, as it 

 can not be split by any possible means. 

 From a paper read by Mr. P. L. Simmons 

 before the Society of Arts. 



The Dnk-dnk. According to Mr. Wil- 

 fred Powell's "Among the Cannibals of 

 New Britain," affairs in the Duke of York 

 Islands are regulated by an officer called 

 the duk-duk, who appears to combine in 



