lever. The ornamental column forming the stand ol 



the safety valve is cast iron and does much to de< orate 

 the interior of the cab. I he pipe carrying the escaping 



steam projects through the cab roof. It is made of 

 copper with a decorative brass band. This entire 

 mechanism was replaced by a modern saferj valve 

 lor use at the ( Ihicago Railroad Fail (1949) Fortu- 

 nately, the old valve u.i* preserved and has sin< e been 

 replaced on the engine. 



rhe steam gauge is a later addition, but could have 



been put on as early as the 1860's, since tin- most 



\<-< .Hi patent date that it bears is 1859. It is an 



Ashcroft gauge having a handsome -1 •! () locomotive 



. ed on iin silver lace. 



The steam jet (item 3. Eg. 18) is one of the simplest 

 \ci most notable boiler fitting of the Pioneer, being 

 nothing more than a valve tapped into the base ol the 

 Steam dome with a line running under the boiler 

 jai kri to the smokestack. When the valve is opened 

 a jet of steam goes up the stack, creating a draft useful 

 for starting the lire or enlivening u as necessary. 

 This device was the invention ol Alba I . Smith in 

 lo~>_'. according to the eminent 19th-century technical 

 writer and engineer Zerah Colburn. 18 



The two feedwater pumps (fig. 20) arc loci ted be- 

 neath the cab deck (I, fie;. 17). The) are cast-iron 

 construction and are driven by an eccentric on the 

 driving-wheel axle (fig. 27). The airchamber or 

 dome (1, fig. 27) imparts a more stead) How ol the 

 water to the boiler by equalizing the surges of wain 

 from the reciprocating pump plunger. A steam line 

 (3, fig. 18), which heats the pump and prevents 

 freezing in cold weather, is regulated by a valve in 

 the cab (figs. 18, 27). .Vote that the line on the right 

 side of the cab has been disconnected and plugged. 



The eccentric drive for the pumps is unusual, and 

 the author knows of no other American locomotive 

 so equipped. l.astwick and Harrison, it is true, 

 favored an eccentric drive for feed pumps. Inn the) 

 mounted the eccentric on the crankpin of the rear 

 driving wheel and thus produced in effect a half- 

 stroke pump. This was not an unusual arrangement, 

 though a small crank was usually employed in place 

 of the eccentric. The full-stroke crosshead pump with 

 which the Jenny Lind (fig. 22) is equipped, was of 

 course the most common style of ivv<.\ pump used in 

 this country in the 19th century. 



( )f all the mechanisms on a 19th-century locomotive, 



1 /i rah CoLBURN, Recent Practice in Locomotio* Engines (1860), 

 p. 71. 



Figure 19. Ba< km id of the Pioneer. 

 (Smithsonian photo (.8069! 



the feed pump was the most troublesome. If an engi- 

 neer could think of nothing else to complain about, 

 he could usually call attention to a defective pump 

 a\u\ not be found a liar. Because of this, injectors 

 wen- adopted after their introduction in I860. It is 

 surprising that tin- /' • r, which vs. is in regular 

 service as late as 1880 and has been under stream 

 many times since for numerous exhibitions, was never 

 fitted with one of these devices. Because its vtn>k<- is 



PAPER 42: THE "PIONEER" OF 1851 



iy) 



