LABORATORY ARTS 



SECTION I 



WOODWORKING 



I. TIMBERS. 



THE principal woods used in instrument making are : " Bass " 

 wood (American white wood or canary wood), yellow pine, 

 mahogany, beech, teak, ebony, and box. Less common ones 

 are : Sycamore, holly, " black " walnut, satin walnut, and oak. 



These woods are chosen apart from any consideration of 

 cost on account of certain definite characteristics which are 

 dealt with below. The cost is not taken into account, 

 because 



1. The quantity of wood used is generally small. 



2. The value of the wood is very small in proportion 

 to that of the instrument. 



For each specific purpose in instrument making there is 

 one wood that is most suitable, and this should always be used. 



Timber used in apparatus making should always be ex- 

 cellently seasoned, free from knots, shakes, and sap wood. 

 The finest quality only should be used, save for the erection 

 of heavy mechanical apparatus. 



Bass Wood A soft, light-coloured wood, varying from 

 pure white to green, with black knots. The wood is porous, 

 easily worked, and takes stains, varnishes, and polishes 

 remarkably well. 



If sound and well seasoned, it retains its form admirably, 

 but it is rather subject to dry rot, and frequently an unfair 

 proportion of sap wood is included in boards. 



Its cheapness, the ease with which it is worked, and the 



B 



