The final survivor of this group of early locomotives is the _Memnon_ (figure 59), built for the Baltimore and Ohio in 1848 by the New Castle Manufacturing Co., New Castle, Del., under subcontract to Matthias W. Baldwin. It is one of a small group of similar freight engines built by Baldwin, who won the contract as a result of his bid in reply to a B & O advertisement in the “American Railroad Journal” of October 1847. The design of the _Memnon_ class of locomotives followed closely that of the _Dragon_, a slightly smaller locomotive built by Baldwin in late 1847 and placed on the road in January 1848. All had an 0-8-0 wheel arrangement, and were intended for heavy-duty work with freight trains. The general design of these locomotives had been originated by Baldwin in 1846 in an order of freight engines built by him for the Philadelphia and Reading. The _Memnon_ type of engine had four coupled driving wheels on each side, and early reports give their diameter as 43 inches. Today’s measurement of the _Memnon_ reveals the diameter of its wheels, undoubtedly replacements, to be only 41 inches. The wheels on the two center axles are unflanged, the better to negotiate curves of limited radius with its wheelbase of 135 inches (in 1847 the shortest curve on the B & O had a 400-foot radius). The inclined cylinders have a 17-inch bore and a 22-inch stroke, and the valve gear is of the Gooch stationary link type. The _Memnon_ is now operated on a steam pressure of 65 pounds per square inch, although it originally operated on 100. [Illustration: Figure 59.—Recent photo of _Memnon_, built in 1848 by New Castle Manufacturing Co.] [Illustration: Figure 60.—_Memnon_ as it appeared shortly after January 1, 1884, when it had been renumbered “13.” A few years later it was given back its original number, “57.”] The original specifications, as set forth in the B & O advertisement, called for a locomotive weight not to exceed 20 tons (of 2,240 pounds). According to J. Snowden Bell, the weight amounted to about 52,000 pounds at first, but changes reduced it to about 47,000 pounds. It would be interesting to know what parts, unnecessary enough to justify their removal or so sturdy that they could be drastically lightened, were involved in changes that reduced the total weight by 5,000 pounds. Today, the unloaded weight of the engine and tender together is 74,700 pounds. The tractive force is 8,580 pounds. As was true of the Baldwin-built _Pioneer_, the cowcatcher of the _Memnon_ was not installed originally. This class of locomotive, which burned bituminous coal, introduced to the B & O the grate having a rocking bar in the center, with fingers on each side that interlocked with projections on fixed bars in front and behind. The rocking bar operated from the footboard.