Steam launches were a familiar sight at the Oxford and Cambridge boat races and their construction was rapidly becoming a separate branch of engineering. It was recognised at the time that the weight of the boat and machinery should be kept as low as possible without diminishing efficiency. Generally, steam launches were lightly constructed, wood being the favoured material for the hull. "Double cylindered engines" (presumably twin cylindered inverted-vertical simple) were preferred with steam supplied by either vertical or horizontal boilers and one or two screws.