VARIETIES OF WOOD DRAWINGS. 65 



SEASONING OF THE WOOD. 



The wood that is employed by the best builders is sub- 

 mitted to a long and thorough course of seasoning before be- 

 coming composite parts of a carriage. Formerly, time alone 

 rendered the wood proof against shrinkage, etc., and it was 

 kept in its raw state for a period varying between two and 

 three years. The drying kiln has greatly shortened the time 

 required for seasoning the woods used in manufacturing the 

 cheaper grades of carriages. The materials thus treated have 

 all the sap driven out and the fibre compressed by the appli- 

 cation of pressure varying between ten and fifteen tons to 

 the square inch. 



VARIETIES OF WOOD. 



The varieties of wood that are employed in carriage 

 building and the purposes for which they are used are here 

 given in tabular form : 



For the under-carriage, white and red hearted ash. 



For the naves or hubs of wheels, elm. 



For the spokes, hickory and oak saplings. 



For the flooring, deal, fir and pine. 



For the roofing, fir. 



For the panelling, mahogany, cedar, birch, walnut and chestnut. 



For wooden rims of wheels, ash, hickory and beach. 



For the framework of the body, ash. 



For shafts, ash. 



For poles, ash. 



DRAWINGS. 



After considering and fixing upon a scheme for some ve- 

 hicle, first as a whole and then the proper relationship of the 

 subordinate details, the designers commit their scheme to 

 paper in a rough drawing. When a carriage is to be built a 



