While owned by the Michigan Central, it 

 had been altered in several ways, the princi- 

 pal change being in the valve motion. The 

 locomotive originally had a single fixed eccen- 

 tric for each cylinder, with two arms extending 

 backward. These arms were fitted with drop 

 hooks to engage with a pin on a rocker arm 

 that actuated the valve rod. The new motion, 

 installed by the Michigan Central, uses double 

 eccentrics with V-hooks for each cylinder. The 

 cab and the cowcatcher, not applied to the 

 locomotive when it was constructed in 1836, 

 are of a slightly later period according to an 

 article in "Baldwin Locomotives" (vol. 10, No. 

 2,October 1931,pp. 3,4). 



In common with many of the other surviv- 

 ing old locomotives, the Pioneer has been on 

 exhibition at many places, including the Ex- 

 position of Railway Appliances at Chicago in 

 1883, the World's Columbian Exposition held 

 there 10 years later, the Louisiana Purchase 

 Exposition at St. Louis in 1904, the Chicago 

 World's Fair 30 years later, and the Chicago 

 Railroad Fair in 1948 and 1949. At the latter 

 fair it operated under its own power every day 

 each summer, requiring only the replacement 

 of the old boiler flues with new ones of sturdier 

 construction to make it again serviceable. In recent years it 

 has been exhibited at the Museum of Science and Industry 

 at Chicago, but is now stored in that city in one of the shops 

 of the Chicago and North Western. 



Not a great deal is known of the early history of the 

 Mississippi (figure 48), which is now exhibited at the Mu- 

 seum of Science and Industry at Chicago. Originally it was 

 used on a pioneering railroad operating east out of Natchez 

 in the late 1830's. Some writers have contended that it was 

 imported from England. Others, including Angus Sinclair, 

 the railroad historian, have stated that it was probably built 

 by the New York firm of H. R. Dunham and Co. 



55 



