could evaporate water with nearly the same efficiency. And as 

 coal burning grew more popular, it became necessary to use iron 

 to resist the abrasive action of the coal ash passing through the 

 tubes. The good sense of making the entire boiler assembly of 

 one material, with a view to uniforixi expansion, is obvious. 



As many readers may know, an intense controversy over the 

 relative merits of the suspended or stationary, and the shifting-link 

 motion arose during the 1850's. The stationary-link valve motion 

 was used on many Moore & Richardson engines after about 1 853, 

 although by i860 the triumph of the Stephenson shifting-link motion 

 was undisputed. The following excellent discussion of the use of 

 the shifting link by the Cincinnati Locomotive Works is reproduced 

 from the Railroad Advocale of June 16, 1855. 



In looking over the report of the Cincinnati, Hamilton and Dayton 

 Railroad, we noticed in the table of engines and engine repairs, that 

 three quite new, Cincinnati built engines, had been fitted with new 

 link motions during the past year. We noticed the fact, as implying a 

 singular and unusual decay of the link-motion, and we suspected that 

 the links had not been case-hardened or that the studs and joints were 

 too small or too short. 



We have since learned that these engines were originally fitted with 

 the stationary link, or link suspended from a fixed point; the valve rod 

 being raised and lowered, instead of the eccentric rods. It was found 

 by comparison with other engines having the shifting link, such as that 

 of Rogers' engines, that the latter was more durable, and that it worked 

 steam more economically, so as to use much less wood. 



The master of machinery of the road, Daniel McLaren, Esq., there- 

 fore altered the link motions on the three engines, all of which were 

 built by the former firm of Harkness, Moore & Co., now Moore & 

 Richardson, and all of which were in all other respects, as excellent 

 machines as any upon the road. (We will say that the road is well 

 supplied with Rogers' engines, and with machines from Taunton, and 

 from the Boston Locomotive Works.) 



Since the alteration of the links, which were originally applied as a 

 test of the motion, Mr. McLaren finds the engines require less repairs, 

 and save much wood. The engines, each of 23 tons weight, are now- 

 running on passenger trains, using but one cord of wood for each 45 

 miles run. 



The suspended link, or stationary link is but little used. It is applied 

 by one builder at Paterson, who has adhered to it we believe for above 



37 



