46 THB PRINCIPAL U8ES OF WOOD. 



For all other descriptions of buildings, the timber should be 

 durable, especially pieces placed in contact with earth or mortar 

 or used in the roof, which last should at the same time be light 

 and possess great transverse strength. Durability, is particularly 

 required in timber used for wall-plates and in terrace roofs, as 

 fungi everywhere, and white-ants in most places in the plains, 

 attack it on the concealed side which is in contact with the masonry. 

 Except in roofs covered with cylindrical tiles or thatch, the timber 

 must be all sawn and squared pieces without any sapwood. Well- 

 seasoned teak poles, floated or washed by the rain during a whole 

 monsoon, last for at least 30 years under well-laid tiles or thatch. 

 The wood used in boarded ceilings and floors and in every portion 

 of a door or window should not be liable to warp, and should expand 

 and contract as little as possible with the varying humidity of the 

 air. The wood of the threshold should be hard and tough, as also 

 that of floors that are not to be matted or carpetted. If beauty 

 and ornament are desiderata, the grain and colour of all the visible 

 pieces of timber should be handsome, especially in doors and 

 windows, and wherever there is any moulding. Wainscoting, by 

 reason of the great abundance of insect life, is out of place in India. 



2. Superstructure of bridges and piers and of other similar 

 erections. 



Here, more so than in house building, strength and durability 

 of the highest order are essential, since the structure is not only 

 exposed to the full and continuous influence of the weather, but is 

 also subject to the heavy shocks and vibrations caused by traffic, 

 &c. And in addition the wood must be elastic. Hardness and 

 toughness are also requisite in pieces subject to the direct wear 

 and tear of traffic. 



AeTICLE 2. TiMBEB USED ON OB IN THE GEOTTND. 



The principal uses for such timber are for piles, for strengthening 

 roadways and stream banks, for railway sleepers, for timber slides 

 and sledge roads, for palisading and fencing, and for mine props. 



1. Piles. 



For the foundations of bridges and other heavy structures, when 

 a firm bottom cannot be easily reached, long logs are driven intc 

 the soft earth in order to support the masonry. As in most cases 

 the logs are placed in the most favourable conditions for the growtl 

 of fungi (sufficient warmth, moisture and access of air), only ex- 

 tremely durable wood should generally be used ; and as the piles arc 

 driven in with heavy blows, the wood should also be as tough and 



