HISTORY OF MARINE ARCHITECTURE.

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in the impulse of the vessel itself. The rower in the second tier sitting at L,moving his handle from e to j\ and from thence to g , where it takes the water,by drawing it back in like manner with the former, produces a similar effect.In the third tier, the rower sitting at M, and moving his handle from h to /,and afterwards to k t will, on drawing it back to //, be nearly as fortunate in theattempt to afford his portion, or share, towards the general impulse.

The fourth rank of rowers becomes almost useless, because it is very 'evident,that the immersion of the oar must rather retard than promote the course ofthe vessel, unless the stroke which followed it was more forcible than appearspossible for it to have been. The slightest consideration will be sufficient toconvince us, that the handle, pushed forward in its proper direction, from / to w,must be raised to n before it can take the water, and that being drawn back, asit must necessarily be, in a line from n to /, the assistance it affords the generalpurpose cannot in the smallest degree avail.

The fifth tier becomes still more unfortunate ; for, after the handle has beenpushed forward from o to p, it must then be raised to q before it can touchthe water, and will, even admitting that to be practicable, in much greaterdegree impede than accelerate the motion of the vessel, in the attempt ofbringing: it down to its first station.

If any person should be hardy enough to pursue the idea still farther, andsuppose tiers additional to these, the difficulty will be found to increase ina ten-fold ratio : of course, the absurdity, indeed the impossibility of theproject will become most glaringly conspicuous, in consequence of the extrava-gant height to which the handle of the oar must of necessity be raised abovethe horizontal line of impulse, so that the blade shall touch the water. No-thing, therefore, can be more ridiculous, than the opinion entertained by many,that a vessel having forty banks so arranged ever existed, since it is very evident,that all tiers of oars beyond three must tend more to impede than promote thecourse of the vessel.

If it should be supposed, in conformity to the opinion and positive assertion ofsome, that the handle of the oar did not extend far within the row-port, the diffi-culty is by no means lessened, and the absurdity is still increased, for how is itpossible that a spar of magnitude sufficient to form an oar of such wonderfullength as it must necessarily have been, could be managed by one man, whenit is well known, that the oars of modern gallies, which (speaking compara-tively with those now alluded to) are of very diminutive size, cannot be

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