Mr. Sheldrake on the Richmond Sleam. Boats. 



1817.] 



some other power, or till the water is 

 deepened for her to float of lierselfl 



The fact of two hundred and eight 

 tons drawn two miles and a half per 

 hour by three horses, bein^ established, 

 will shew wiiat they have to perforni 

 who undertake to enter into competition 

 with this general mode of conveyance, 

 either as to expedition or expciice. I 

 doubt if any engineer, who has been en- 

 gaged in such undertakings, would en- 

 gage, under proper responsibility, to 

 apply au engine that should impel that 

 barge, equally loaded, an equal distance 

 in the same portion of lime; or, if he 

 would engage to constrnct any vessel 

 that, with any engine, would convey 

 the sartie quantity of goods with eq":d 

 expedition: but, as this may be doubt- 

 ful, we may be allowed to ascertain 

 that point, about which there can be 

 no donbt at all, viz. the comparative 

 expence. 



I have no data that will enable me to 

 estimate the number of bajges that 

 work between London and the upj>cr- 

 most navigable part of the Thames, but 

 the numlter must be very great. Thus 

 much, however,, is certain, that they are 

 constructcfl to what is thought the best 

 advantage for their various uses; when 

 wanted, horses, which are kept for the 

 purpose by another set of persons, are 

 feircd to work them, at au expence pro- 

 porfioued to the work wanted, and no 

 more ; but, if the proprietors ol' these 

 barges were induced to apply them, in- 

 stead of horses, to do their work, they 

 must add an engine to each barge, at an 

 expence equal to, if not greater than, 

 the cost of the barge; in the [iresent 

 state of things, all the work on the river 

 is done liy a certain number of horses, 

 each person paying for the quantity of 

 labour he requires, and no more; but, if 

 steam were to be substituted for horses, 

 the quantity of money that is u(jw sunk 

 in the purchase of barges, must be more 

 than doubled to purchase engines; to 

 which must be super-added, the expence 

 of working, which, on the Thames, at 

 least, would amount to more than the 

 price of labour of the horses that are 

 necessary to do the work ; and would, 

 altogether, be an absorjition of capital 

 which the proprietors of this kind of 

 property can have no itidnccmeut to 

 subject themselves to. 



Still, it will be acknowledged, that 

 the introduction of steam-boats will 

 l»c attended with many advantages ; and, 

 as it is acknow ledged that they are at 



Monthly Mi*. No. 2&2. 



505 



present in their infancy, it may not he 

 unacceptable to ofl'or some of those cir- 

 cumstances which have occurred to nie, 

 and which may be of use to those who 

 employ themselves on this subject. 

 Many of those who have attempted to 

 use steam-boats have supposed it was 

 only necessary to get a vessel and an 

 engine, and the whole business was 

 done; to which, some have added, that, 

 ifa;i enguie of given power could drive 

 a boat at a certain rate, an engine of 

 greater power would drive the satne 

 boat at a greater rate, in proportions 

 which they think they have established; 

 whence they infer, that, by increasing 

 the pawer of their engine, tliey may in- 

 crease tlte velocity of their vessel, al- 

 most ad infinittnn: all which has proved 

 to be false in point of tact ; and, by ad- 

 verting to the known laws of nature, as 

 applicable to the subject, will be lound 

 to be actually imj)ossible. 



'J'he great ease with which particles 

 of water yield to the pressure of any 

 more solid substance (hat floats in it, 

 is the real cause of the facility witii 

 which any body is transported by draw- 

 ing upon the water, when compared to 

 the labour that is necessary to transport 

 the same body upon land : in the case 

 ot the barge, already mentioned, the 

 ground was the medium of resistance, 

 the horses the moving power, and their 

 feet the point of contact, by which the 

 ;.)Ower was brought into action upon the 

 body to be moved: the barge was, at 

 least, twelve feet in tlie beam, and, at 

 the time I saw her, drew nine feet 

 water; that is, she oj)po5ed a surface 

 of 108 square feet to the action of the 

 water. Some power was lost by the effect 

 of the rope occasionally dipping in the 

 water; but, notwithstanding that Joss, 

 the power of three liorsos, estimated at 

 640 pounds, displaced the particles of 

 water contimially, so as to allow 208 

 tons to pass through it at the rate that 

 has been mentioned. 'J'he same weight, 

 if brought to act upon the .same body, 

 in any other situation, by passing over a 

 puUy, would have produced no effect 

 whatever. 



But, if the same barge were to be 

 moved through the water by any power 

 contained withui itself, and acting upon 

 the water through which the vessel 

 mii.st be moved, the power required to 

 move it would be much greater, if it 

 were possible, to move it at the same 

 rate, by any power w hatcvcr, for reasons 

 which may be made cviilcnt. The 

 3 T wat« 



