THE TECHNOLOGIST. [March 1, 1865. 



342 WOOD FOR RAILWAY SLEEPERS. 



now useless, and generally left to rot on the ground or to be consumed 

 by the annual jungle fires. It is this that Dr. Brandis would propose to 

 utilise for sleepers, and he calculates the probable yield from this source 

 to be 300,000 pieces per annum. 



Another wood supplied by the forests of Burmah in great abund- 

 ance, and which is scarcely less durable than teak, is ironwood. This 

 is now being tried for the first time on the East India Railway, the 

 sleepers being cut to half the usual thickness, viz., 2^ inches (instead of 

 5 inches), a plan which, if found to answer, will remove much of the 

 objection attaching to this wood on aceount of its great weight, 65 lbs. 

 per cubic foot. The ironwood of the forests of the West Coast has been 

 tried on the Bombay and Baroda line to a considerable extent, but, like 

 many other hard" woods, was found to be split by the spikes. The 

 strength of the ironwood to resist breakage has been tried by Mr. Power, 

 who finds that the creosoted pine sleepers, 10' x 10' x 5", were broken 

 by a weight which the ironwood of half the thickness resisted without 

 fracture. Experience will show whether sleepers so thin as 2 -J" will 

 deaden vibration to the same extent as the 5" sleepers of the softer 

 wood. Judging d priori, we should doubt whether they would do so, 

 and whether this would not prove an objection to their employment. 



Dr. Brandis suggests the trial of some other native woods of the 

 Burmese forests, which are found in sufficient quantity in forests com- 

 paratively easy of access to justify the assumption that they may some 

 day form an article of trade on a large scale* These are — 



Weight of one cubic 

 foot of half- seasoned wood. 

 Seet (Albizzia data) . . . 42 to 55 lbs. 



Nabhay (Odina Wodier) ... 65 „ 



Bambouay (Careya arborea) . 55 „ 



Pyinima (Lagerstrcemia regince) . 44 „ 



Htonksha ( Vitex leucoxylon) . 42 „ 



They are less durable than teak, but might be procured at a cheaper 

 rate. The Pyirnrna might be imported from Chittagong at three rupees 

 a piece. It is liable to be attacked by white ants, but experience seems 

 to show that railway sleepers are less exposed to destruction from this 

 cause than wood in other localities. It is well known that white ants 

 will only work in undisturbed ground, and it seems probable, from the 

 extreme rarity of railway sleepers being attacked by them, that the 

 frequent vibration to which the latter are exposed drives away or 

 destroys the insect. — The Engineer's Journal, Calcutta. 



* Dr. Brandis' accounts of the woods of British Burmah will be 'found in the 

 second volume of the Technologist, page 321. 



