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On the most effective Employment of Steam- Power in general, 

 arid more particularly in Mercantile Navigation. By Cap- 

 tain M'^KoxNOCHiE, R. N. (Communicated by the AMthor.) 



1 HE prevailing objection to the use of steam in mercantile na- 

 vigation is its inordinate cxpence ; and yet, in every other dc- 

 partmpnt of art in which a great force is wanted, the substitu- 

 tion of machinery for manual lal)our, and of a certain for an un- 

 certain moving power, has been productive of economy, not of 

 expence. This consideration, then, would seem to indicate, that 

 there is some mistake in the usual mode of applying steam to the 

 purposes of navigation, which causes this remarkable anomaly ; 

 and if we consider the matter farther, we shall, I think, disco- 

 ver another discrepancy, which goes far to solve the difficulty. 

 In most other instances in which a great power is employed 

 with a view to a given effect, the power is generated in one 

 chamber, and applied in another, without the different sets of 

 apparatus requisite for the production and application interfer- 

 ing with, or cumbering each other. Inordinary navigation, in 

 particular, this prevails, for the sails in no degree, and the masts 

 but a very little, interfere with the stowage of the vessel they 

 propel. And in steam navigation alone (or only in common 

 with the first and rudest method of maritime communication, 

 that effaited by oars), the horses are, as it were, received into 

 the inside of the carriage, at once destroying its capacity, and 

 exerting their own power to disadvantage. Both analogies, 

 then, point one way, -—both seem to me to conducts to steam- 

 towing, as the only modification of steam-navigation which 

 can be made generally available for mercantile purposes ; and 

 the further development of the subject is the purpose of 

 this paper. On a former occasion I considered it as applica- 

 ble to the maintenance of ferries *. I shall now, I* Describe 

 the sort of vessels which I think best fitted to be connected to- 

 gether, and thus employed for general purposes. II. De- 

 tail some of the advantages which would seem peculiar to^s 

 mode of navigation: And, III. Having thus got a distinct view 



" Edin. New Phil. Joum. July IftW. 



