56

HISTORY OF MARINE ARCHITECTURE.

higher, the rowers would stand, rather than sit, and then be deprived of partof their impulsive strength ; if they were lower, they must be obliged to rise inthe action, and their force be equally abridged by the contrary cause. The dimen-sions apparently most proper to adopt are, that the steps, or resting places, for thefeet of those who worked the upper tier, shall be four inches lower than theseats of those in the second tier, and the interspace between the seats them-selves eighteen inches, nine feet sufficing to contain six seats.

Let the seats be moved so far forward before each other, that a rower sitting'at E in the second tier from the bottom, may touch with the flat or sole of hisfoot, the foot-board fixed under the seat of the rower in the lowest tier at D;and in like manner, the rower on the seat F may touch the foot-board underthe seat E, and so on. It will readily be seen by this oblique disposition, thatbetween each seat there should be, on the base of the parallelogram, a distance oftwo feet four inches, which will afford a distance of seven feet between the seatsD and K, which are, nearest each other on the same line. The breadth of theseat itself, and the foot-board, amount to one foot: the oar itself will requireto be pushed forward, at the time of any great exertion, four feet six inches:the breast of the rower projects nine inches; and the knees of the person in thetier above as much : these being added together, make exactly seven feet.

The required space for the motion of the oars must render it very evident,that they could not possibly be placed nearer each other than what is hereallowed. No small difficulty, however, occurs in the attempt to explain by whatmeans so many tiers or banks of oars could be worked. This mystery hasindeed carried with it so much weight, as to induce many persons to treat as afiction the accounts given bv the ancients of the many distinct tiers of oarsrising above each other, either in a direct or oblique line. It is to be hoped,therefore, that an attempt to explain this problem, which has so long distractedthe minds of the inquisitive, will not be thought labour entirely thrown away.

In the annexed Figure, the rower sitting in the lower tier on the bench K,pushes forward the handle of the oar from A to B ; and by a second motion,from thence to G ; the handle having reached that point, the blade then takesthe water, the surface of which is represented by the base line a b, the seatbeing; about one foot lower than the seat of the bottom rank. The handle of theoar is forcibly pulled back from G to A, whence it first commenced its motion ;and the resistance of that space of water, through which the blade passes withsome degree of rapidity, will be found to afford a proper and sufficient share

in