| Description | Written from Lambeth, London. The letter apologises that Field cannot give Brunel the information that he wants about the immersion of paddle wheels based on experiment or actual data but he can give Brunel the results of his general experience, which he proceeds to do; describing the depth of immersion beyond which the paddle wheel engine's performance is reduced, the optimal depth for the engine and the working and the depth at which the paddle wheel and engines work at above-optimal levels. The letter also describes the optimal width of the paddle wheel and the breadth of the paddle boards. The letter also expresses Field's hope that Brunel's Great Ship may be able to help advance the science of steam navigation. |