ECOXOMICAL TllAXSPORTATION. 



229 



trestle. Seen at a distance, here they are hoisted with 

 a windlass to a certain height, as the case may be 



(see fig. 48), to obtain the given start; for example, 

 for a distance of 100 m. (328 feet) this would be 2.10 

 metres (G.8 feet). These arrive in a perfect state at the 



