2 NOTE ON GUMHAR. 



by a white line or pores in the spring wood. It is easily worked and 

 takes varnish well. On a vertical section the pores show as fine 

 wavy light brown lines. The rate of growth is fast, as few as two 

 annual rings to an inch radius having been recorded. The Dehra 

 Dun specimens average four rings. 



r 



Durability. The timber lasts well as a rule in buildings, and in fresh 

 and tidal water and does not warp or crack readily. Until it loses the 

 bitter principle in the wood white-ants do not seem to attack it. House 

 posts which had been in use in Bhamo, Upper Burma, were found to be 

 in good order after 50 years. Dug-outs are said to last about 8 years. 

 Wood placed .in the sea in Madras was found to be badly attacked by 

 the teredo, so that it is not always advisable to use it in tidal water. 



Weight. The average weight of the seasoned wood per cubic foot 

 is about 36 Ibs., the specimens weighed varying little, no example 

 weighing more than 38 Ibs. (Gamble) . It can be floated after drying 

 for a short time, but should not be kept long in rafts as it absorbs water 

 and sinks. 



Strength. The value of P, which represents the strength of a bar of 

 timber calculated from the length between supports, breadth, and thick- 

 ness of the bar, and the weight in pounds placed in the middle of this 

 which causes it to break, is about 460 (Gamble). For Sal it is 790, for 

 Teak 600 and for Shisham 796. 



Fissilility. From tests made by Mr. K. S. Troup, the timber 

 appears to be rather difficult to split. The tests were made with dry wood 

 and gave an indicating figure of 6*17, Teak being easily split and giving 

 1-75, Deodar T85, Acacia Catechu 2-98, Padauk 3'83, Shisham S'O, and 

 Sal 9-33. 



Calorific power. The Forest Chemist, Mr. Puran Singh, when test- 

 ing the calorific power of 56 of the commoner Indian timbers, found that 

 Gumhar comes about the middle of the list. The number of British 

 thermal Units generated by this timber is 8,075, the same as one of the 

 Gardenias. Yew gives 7,394, Bombax malabaricum almost the same as 

 Gum/iar, and Teak, Sal, Deodar and Pines a good deal more. 



Seasoning. The timber seasons well and has long been known as a 

 good wood to use when shrinkage is to be avoided. In the Southern 

 Shan States the trees are girdled and left standing for some months so 



