98 BULLETIN 119, U; S. NATIONAL MUSEUM. 



tion by a wedge driven between the ring and the rail stem). Chairs 

 and other joint fixtures attached entirely to the base of the rail were 

 also experimented with, but generally without satisfaction, judging 

 from the fact that none survived. 



The difficulty in making good joints with the pear-headed rail 

 was overcome by some of the engineers by planing away a portion 

 of the head of the rail for a foot or 18 inches from each end. 

 On the Pennsylvania Railroad and on the Belvidere-Delaware Rail- 

 road the rails in some cases were planed with special reference to 

 the use of a splice bar, almost square at the rail head and base, as 

 early as 1857. 



In 1853 an interesting experiment was tried on the Boston and 

 Lowell Railroad. After running for some time on the. head (pear- 

 shaped) of the rail it was inverted. The effect of three years' run- 

 ning on the base was to round over the outer edges. 



COMPOUND RAILS. 



The difficulty in obtaining satisfactory joint fixtures on the 

 American pear-shaped section led to the introduction of the com- 

 pound rail. One of wood and iron was designed by Benjamin H. 

 Latrobe in 1841 for the Baltimore and Ohio Railroad. The Z iron 

 was 5 inches high and weighed 45 pounds to the yard. The track 

 consisted of longitudinal undersills, which supported the crossties, 

 3^ by 6 inches and 7 feet long. The wooden portion of rail was made 

 to fit closely against the stem and under the head of the Z iron, to 

 which it was joined by f-inch bolts with screw nuts. The iron 

 and wood stringer was laid to " break joints," so that no splice bars 

 except a base plate was needed at the joints. 



A Section of an Ingeniously Devised All-Iron Compound Rail on the Balti- 

 more and Ohio Railroad in 1848 is in the Collection. 



Cat. No. 180,344 U.S.N.M. 



Several of the railway companies in New York laid a large mileage 

 of compound rails of various patterns. Four sections of compound 

 rails in the collection which were in use in New York in 1855 are: 



New York Central Railroad. Sixty Pounds to the Yard. 



Cat. No. 180,236 U.S.N.M. 



New York Central Railroad. Seventy-five Pounds to the Yard. 



Cat. No. 180,229 U.S.N.M. 



Troy Union Railroad. Sixty-five Pounds to the Yard. 



Cat. No. 180,235 U.S.N.M. 



Troy Union Railroad. Sixty-five Pounds to the Yard. 



Cat. No. 180.234 U.S.N.M. 



