CH. Ill FORE-CARRIAGE 29 



have this arrangement, which permits part of the 



machinery to be sunk between the front wheels. 



These plans all depend upon an arrangement of 



parallel bars, with arms that turn the axle-arms and 



wheels, about the end of a fixed M 



axle. If the boots are not too ®=fl 



deep, a coach fitted in this way > c d s * 



will turn, on an almost square <^==i 



. . . 1 Q 1 



lock, round a point inside of the 



spot where one hind wheel ffNs^ 



touches the ground, and the KnT^ 



lowest points of the front wheels * <J<mK\ 



will not deviate greatly from the ^\T ^x\ ... 



lines running through the hind 



wheels, as is shown by the dotted 



lines in Fig. 11, which is only a diagram, and is not 



intended to show details of construction. 



To obtain the greatest freedom in turning, the 

 parallel bar A B (Fig. 12), which is behind the axle 

 and connects the arms, must be as much shorter than 

 the distance on the axle between the joints of the 

 axle-arms as will make the lines of the arms, pro- 

 duced, join at the centre of the hind axle (Fig. 1 2, C). 



The front wheels, when turning, will then assume 

 positions which are not parallel to each other, as 

 they are in Fig. 11, but at right angles to two radii 

 meeting on a line which is the prolongation of the 

 hind axle, and all four wheels will turn round that 

 point, as a common centre, without any grinding 

 upon the road. 



