368 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



MARPING HAULAGE ON CANALS. 



A new system of hanlast- has been tried for the first time in this rountry 



on the RcRent s-ranal, tlirongh the tunnel underSt. John's noo.l. Padding. 



ton. I ,s the .nveniion of Captain I5eadou,and is said to have complelely 



succeeded. Me have some impression that a similar ssslem has beeo 



fr,™ lis merits, but otherwise, proves that ihe invention is a practicable 

 one. The plan consists of a steam tug-hoat and ropes, as shown in the aii- 



2tt 1 vv",l "",""''■ ^'^- ' ;■' ^ '!'" ^•''■"•«'"' «S- ^ a plan view, of a vessel 

 htttd with steam power and the haulage ropes. 



[Dec. 



A A engine and boiler, B C two reels or cylinders, carrying wire ropes 

 D and I- passing out fore and aft of the said boat. 'These reels have'^fn 

 front of them guides to regulate the wire ropes in winding up, and passing 

 off such reels, and they are connected with the driving shaft of the entrine 

 by endless chains shewn in fig. 2, and are placed in the boat fore and 

 aft he engine and boiler. F. ach reel contains six miles of wire rope, which 

 IS alternately laid down in the bottom of the canal. The ends of these rones 

 are attached to the reels, and the two other ends of such ropes are fastened 

 to posts in the canal banks ; and when the one, say the rope D. is wound 

 up, the entire working end of the other, E, is down in the canal. 

 1 be reels are thrown in and out of gear by the reversing motion of the en- 



Fig. I. 



■"-"-'»'«>•;- <-s>A 



Fig. 2. 



gear'anT'therTu " boat is as follows : the reel C is thrown out of 

 der or rp. R 1 '" " r^""' ""' '■""'"^^ ="•'■ s^' i" "lotion, and the cy in 

 der or reel B revolves and winds in the rope D, whilst the cylinder or reel 



.^.e f.io" c^f th?r7„"V'"' Z'r- '^'^^''"^'' '" revolv:,'ind does soby 



eca'a aslhehoT ' ",'"'': " "'"' gradually delivered down into 



end of tte lo e n^h '""'"""' "'^S' ^^ '''°° "' ""' boat arrives at the 



end of the lopeD the engine is reversed, the cylinder or reel B is thrown 



"i"rhrro,;e«. ,■"■;.'?'"%'" "'.'"' ""^ ^°P^ ^'-•' ""^ < vlinde H to de" 

 li.er the rope 1) , so that, m fact, by simply winding in and out of t:;e two 



ropes is the boat propelled along backwards or forwards six miles each 



h J," '!T ''"'"' °^ •'»'>'' along, they are attached by a tow-rope to thig 

 boat, and proceed with it to the end of its rope or station. They ar t e,! 

 disconnected from the boat, and attached to another similar one, "and taken 

 oihe SIX miles, and so on to Ihe end of their journey. The cana s thus 

 so't'har h ? " ''?.'' of stations, having tug-boats to stirt atappomfed inie, 

 80 that boats, as they arrive, are forwarded with regularity. ' 



RAILWAY CURVES. 



,,loyment," in the" Journal fjr October p 300 ''"""' ""' ""^ '^"'^ 



U here the extremities of a chord line have been already ascertained and 

 given, and sf.kn there can be no doubt of the simplicIlyVnd alcu^e^ "f 

 your correspondent's method, provided the localities be s liUble for its exe 

 cntion. ndeed, I am much inclined to think that, unde those^ e""' 

 stances, U ,s superior, being less complex, to any otii'er method I hale me"t 



I would suggest that it is better to avoid referring to tabular information • 

 but to be as independent of it as possible. The versed sine of iny "c mav' 

 be readily found, where the radius and chord are given, by the 47th nro 



»eat. After this, the time and trouble of chaining the whole length of the 



chord of half the arc may b e saved, for it will be fou nd to be equal to 



c„.i , I .u ^ *,i'5* '''""■'' "''"'« *'"'■■) "^ + ('-ersed sine) 2, 

 is ver "i"^ ^^u V ""'"l ^' ''^^"'""^ '° ^' "''^'"'<^'i ■' and at this point, 

 orZr^iTn^^ \ ^r'"' "V°. ""^ "■'^"•'^ ^'' ■' "'^' i^-F™" "-e square' 

 «1 I r Ih^ ""^"^^ '*'■"' ''''duct the square of half the chord of half the 



of 1,1 . I ^^"".y'O'^ --oot of the dilference, deducted from the radius 



on „;«/'■''' "■'"''^''1'"'' '" '""^ versed sine of half the arc; and so 

 on, ad injinitum. ' 



The chief object I had in view, in recommending the use of mv instrB- 

 Wlln,"!,'","''''"'''''']''^' "'""'*'' ' "«y ^ay, under any circumstances, 

 nls, ,r r ".""'■,' ^"'" '"Z"'"':'^' tbe tangent may either be made to work 



past ihem or to stop short of them. &c. ; a new calculation will of course be 

 requisite to be made at each alteration of the tangent, but that can very soon 

 be done Another a.lvantage is, that it does not require to see further thao 

 the length you choose, or fiud it convenient to make the tangent. 



Military Library, 30, Charing Cross. "' *"' 



os^rf'I'""';" ""^.'^fi."'":'"; of ""y " ^""e Tracing Instrument," " a 6" is 

 used lor c b, and " effect " for offset. 



