CONSTRUCTION OF COACHES. 89 



pull the ponderous coaches out, would have dragged 

 the modern stage-coach all to pieces. It is somewhat 

 curious that, although the stage-coach-builders en- 

 deavoured as much as possible from time to time 

 to improve the construction of their coaches in order 

 to make them light, strong, safe and appropriate 

 for the conveyance of a number of passengers and 

 their luggage, the mail-coach-builder made very 

 little alteration indeed in those he built by contract 

 for the Postmaster- General from the reign of 

 George III. up to the time of the contract passing 

 into other hands in 1836. 



Previously, however, to adopting a new pattern, the 

 Postmaster- General very properly consulted persons 

 scientifically conversant with the construction of 

 coaches and their various parts, especially the wheels, 

 and also the leading stage-coach-builders in London, 

 obtaining in this way a great deal of very interesting 

 and valuable information. He observed, that in 

 order to form right opinions on plans of coaches^ he 

 should begin by acquiring an accurate knowledge 

 of the use of wheels. Nothing is more common, he 

 said, than to meet with persons who have formed 

 the most decided opinions on the construction of 

 carriages, without having examined the properties of 

 wheels, or being aware that they are treated by 

 mathematicians as powers, and that all their properties 



