2 S 8 



APPLIED SCIENCE 



well that we are put on our guard against this danger. In the 

 first design a sort of rocking saddle was employed, to allow the 

 strain to be transmitted from one span to the next, but the 

 flexibility of the posts provides amply for this object. Abutment 

 posts are required at intervals, and these can be made use of to 

 provide compensation for changes of temperature, and to limit 

 the stress on the rods. In straight lines I reckon four abutment 

 posts per mile. 



In the short South American line, curves of 45 degrees at 

 the posts will be employed, as shown in the model. At the 

 stations where goods are to be handled, a rigid rod will be more 

 convenient than the flexible rod. A bulb angle-iron, like that 

 shown in Fig. 3 (p. 257), supported every 10 feet, answers well at 



FIG. 5. FIG. 6. 



Weston, and a siding, leading the trucks off this line, has been 

 satisfactorily carried out. The siding leads back to the line at 

 a point between two flexible spans. In fine, it may be said 

 to-night that the problem of the continuous line, whether 

 straight, curved, rigid, or flexible, has been completely solved. 

 Drawings and specifications can be put, without further delay 

 or experiment, into the hands of contractors. Trucks used on 

 ordinary rope lines are designed to be pulled by ropes on a 

 road which is necessarily straight. When trucks of this de- 

 scription, with wheels 8 inches diameter and 22 inches wheel- 

 base (Fig. 5), were tried at Weston, arranged in trains, some 

 new difficulties presented themselves. Any sudden check to 

 the motion was followed by a rearing action, throwing the 



