The _Pioneer_ had a full and active life, for it was in operation 12 years prior to its acquisition by the Galena road and 26 years after (figure 47). It was at one time temporarily lent to the new Chicago, Burlington and Quincy line, until that company was able to buy an engine of its own, and was finally retired by the Chicago and North Western in 1874. The _Pioneer_ is a typical Baldwin design of the period. A wood burner, it weighs 10 tons, has slightly inclined cylinders 11 by 18 inches in size, one pair of 54-inch driving wheels at the rear, and a 4-wheeled swiveling truck at the front. The cylinder bore was originally 10 inches, but in 1872 the Chicago and North Western changed it to the present slightly larger dimension. While owned by the Michigan Central, it had been altered in several ways, the principal change being in the valve motion. The locomotive originally had a single fixed eccentric 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 surviving old locomotives, the _Pioneer_ has been on exhibition at many places, including the Exposition 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 Museum 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. [Illustration: Figure 48.—_Mississippi_, probably built in the 1830’s, with tender of a later period. Photo may have been taken after locomotive was rebuilt for exhibition at World’s Columbian Exposition at Chicago, in 1893.]