four years. Although it involves more joints than the shifting link, we 

 had supposed that it allowed of a stronger and better suspension. The 

 stationary link maintains a constant lead on the steam port, under 

 every degree of expansion, whereas the shifting link varies the lead, 

 generally from 'inth inch at full stroke to /4 or /leths, in cutting off at 

 three eighths stroke. Yet, although the stationary link keeps a constant 

 lead, always the same, upon the port, the mere fact of varying the throw 

 of the valve, varies the period of taking steam, as measured upon the 

 stroke of the piston. With 5 inches throw on the valve and /4 inch 

 lead, the piston will be, perhaps, % inch from the end of its stroke when 

 it begins to take steam. With but 2% inches throw, and the same lead, 

 the piston would be probably one inch from the end of its stroke when 

 it first gets steam to drive it in the opposite direction. 



But with the fair trial of the stationary link on the Cincinnati engines, 

 and with the general preference for the other, or shifting, link, as shown 

 in its adoption by every builder who uses the link, with the single ex- 

 ception named, we must believe that the former (stationary) link has 

 some inherent fault. We are well aware that Rogers first attempted 

 the use of the stationary link, and that he soon abandoned it for the 

 shifting link which he has now used for o\-er five years. 



We think it would be an interesting subject for investigation and 

 comparison, to have the working of the two plans of links made out and 

 published by their respective builders. If any single builder attaches a 

 loss of 10 per cent, of wood to all his engines, by reason of his unsupported 

 preference for a defective valve-motion, both he and the railroad public 

 should know it. 



Despite its failings some roads, including the Little Miami, obtained 

 good results from stationary link motions. William Swanston, 

 formerly of the Little Miami Railroad, commented on them at the 

 American Railw^ay Master Mechanic Association in 1885: 



Some years ago, on the Little Miami Railroad, we had a stationary 

 link on which the lead was constant. Now to get better results [speed] 

 on passenger engines, we increased the lead of the backward motion 

 so as to increase it on the forward motion, and we got good results from 

 that. 



Figures 13, 15, and the endpapers will clarify the exact layout of 

 the suspended-link motion. Notice the forward placement of the 

 rocker. The valve stem is extended through the front of the valve 

 box, offering a larger bearing area. Two points of support are 



39 



