which part? Still's book on Confederate shipbuilding has the basics on the big vessel. It was almost unique among southern vessels (Louisiana had two central wheels and twin props for steering), but similar propulsion layouts with both side wheels and propellers are found among the Union river fleet. Read's memoirs state that the engines for these vessels were "botched together by a shop on Adams street". It would be wonderful if someone actually excavated the wreck of the Arkansas. Her engines are a question mark and it would be interesting to see exactly how they adapted high pressure machinery to twin screws. The layout might also answer the question of why her engines on at least one occasion stopped dead top center. Her propellers are another interesting topic. These seem to have worked well in practice. If we knew the bore and stroke, we could calculate a theoretical output, and from the layout of the boilers and the grates some idea of how much pressure they could generate and fuel consumption. The Eastport and Indianola might give us an idea of how the big vessel might have appeared when completed. On the other hand, if Porter completed his Nashville class design by this time, then perhaps she was a heavily modified vessel of that type. We do know that a flood condition removed much of the bracing for the hull while she was on the stocks causing her to roll to one side. Arguments have been made that Brown had assembled one of the best equipped machine shops in the West at Yazoo City and had the capability to finish his conversions provided iron and more time.