Laboratory Arts 



able to obtain it quickly in any required 

 "width : an3 -thickness, cause it to be the staple material for the 

 construction of stands, boxes, cases, covers, and all appliances 

 which do not involve delicate workmanship. 



Yellow Pine. An expensive, but soft and easily worked 

 wood. Yellow pine is the ideal wood for the amateur ; it is 

 easily worked, cuts without cracking, and does not dull the 

 tools. It retains its shape splendidly; indeed, yellow pine, 

 properly handled, will not warp ; hence it is a favourite wood 

 for important work. It has the property of transmitting and 

 responding to sound vibrations in a remarkable degree, hence 

 it is always used in the making of acoustic instruments organ 

 pipes of yellow pine have a soft, mellow " voice," which is 

 highly suggestive of the properties of the wood. Piano sound- 

 boards, monochord bases, tuning-fork boxes, etc., should all 

 be made of yellow pine. 



Yellow pine hardens on exposure to the air ; consequently, 

 though soft and easy to work, it soon becomes sufficiently hard 

 to withstand the handling usually meted out to laboratory 

 furniture. It is, however, useless in damp situations, and 

 should in all cases be joined with glue rather than nails. 



Mahogany. This wood is a favourite for the making of 

 instrument cases, bases, and back-boards, owing to its hard- 

 ness, and the ease, therefore, with which it takes a good polish. 

 The wood is light red in colour, with highly characteristic 

 markings, but it is usually stained with some oxidizing liquid 

 (bichromate of potash generally) before polishing, in order to 

 deepen its colour. " Bismarck Brown " is also sometimes used 

 for this purpose. 



The wood is very apt to split in working, owing to the fact 

 that the main strength of the wood is in the longitudinal 

 fibres; the connecting cells having thin walls, dry down on 

 seasoning, and form bridges much weaker than the rest of the 

 timber; hence, in working wood such as mahogany, for 

 example, one has to take every possible precaution against 

 the splitting of the wood. 



There is practically no reason for the preference of this wood 

 over bass wood, save for its appearance. 



