232 Capt. M*=Konochie on the most effective Employment 



at once of the means contemplated as applicable to the occa- 

 sion, and of the inducements to employ them, I shall review 

 the difficulties in the way, and what appear to me to be the best 

 methods of obviating them ; in other words, give a brief theo- 

 retical sketch of what may be called the Tactics of Steam-tow- 

 ing. 



I. As a general principle, the steam-boat should not be large ; on the con- 

 trary, it should, in every case, be as small as possible, consistently with per- 

 fect lightness and buoyancy under the weight of her machinery. It is not 

 absolute, but disposable, power that is wanted in her ; and it is easy to con- 

 ceive, that a small actual power in a small boat may have even more of this 

 than a great power in a large boat,— just as a light cutter, manned with six 

 men, may pull faster to windward against a head sea, than a heavy launch or 

 barge with sixteen. But there are other principles also to be attended to, 

 some of them of the more importance (as appears to me), because, although 

 applicable, in a degree, to all steam-boats, they are disregarded in the ordi- 

 nary construction of them ; and have, I think, been overlooked from not at- 

 tending to the rationale on which the forms of sailing and rowing vessels have 

 been, almost intuitively, modelled, and to the entirely different circumstances 

 under which steam is applied as a propelling power. 



Sailing vessels must have a good hold of the water to support them against , 

 their sails; they are, therefore, built sharp, and, as it is called, '-'• long-legged,'* 

 to acquire this. Their masts also are weak, compared to the power of wind 

 to which they are occasionally exposed ; and they are, accordingly, balanced 

 on a central line, the keel, and the hulls of the vessels are rounded off on 

 both sides from it, to facilitate their heeling to a strong blast, and thus in- 

 creasing the support as it is required. And the amount of impelling force, 

 both in sailing and rowing vessels, depends greatly on their length ; and this 

 dimension, accordingly, is of first importance to them, and in Admiral 



Chapman's expression for estimating their velocity (lI . ^ fi V it is the 



principal quantity ; as in all vessels which carry goods, passengers, or a nume- 

 rous crew, it is also that which furnishes the most accommodation. But 

 steam-boats require very little hold of the water. So far from its ever being 

 expedient that they should heel to the wind, the easy and effective working of 

 their machinery essentially depends on their remaining always as much as pos- 

 sible upright. "Whatever the power embarked in them, the impulse is confined 

 to one spot ; at least all attempts yet made to have even two sets of paddle- 

 wheeLs along the length have failed, from the additional, and yet uncertain, 

 velocity which the water acquires after passing the foremost wheel. And 

 tug-boats, besides that they want chiefly strength of longitudinal fibre (if the 

 expression may be allowed), which is in a considerable degree incompatible 

 with inordinate length, scarcely require any accommodation unless for their 

 engine ; and if they can gain buoyancy without great length, are therefore, in 

 every respect, better and handier without it. 



