SCALE-DRA WING. 361 



imagine, would feel interested in knowing something 

 of their construction, which knowledge, I feel assured, 

 will be of service to them in more ways than one. 



Before a carriage is put in hand careful drawings 

 have to be made of it to scale, and although the 

 designing of a carriage does not necessitate any very 

 profound mathematical knowledge or calculations, yet 

 carriage architects, when scale-draughting, require to 

 do their work very carefully and skilfully. In addition 

 to a reduced drawing, full-sized diagrams have fre- 

 quently to be made in chalk on a blackboard, for the 

 workmen to work to ; these are placed up against the 

 wall so that the various timbers used in the construc- 

 tion of the carriage may be compared with such 

 drawings. 



As a carriage is composed of various parts, and as 

 all these parts must exactly correspond with one an- 

 other, it is absolutely necessary that a working draft of 

 the full size be completed before a carriage can be made. 



In the first place, it depends upon the construction 

 of a coach what difference will be required betwixt the 

 heights of the fore and hind wheels, to bring the perch 

 to a proper level ; the depth from front to back of the 

 body ; and the height which it is to be hung from the 

 ground is next required, in order to ascertain the proper 

 length of the carriage, that is, what distance the fore 

 and hind axle-trees are to be from one another ; the 

 particular manner in which the body is to be hung 

 upon the carriage m.ust also be fixed, in order to give the 

 springs a proper degree of curvature. To obtain these 

 particulars a draft is made of the entire machine, and 

 from it the master-coachbuilder at once sees what effect 

 will be produced. In making these drafts, the coach- 

 builder is limited, in a certain degree, by the fashion 



