23$ 



Hydroftatic 

 principle. 



The plunger i 

 counterpoifed. 



General 

 remarks. 



Advantages of 

 this lock. 



No machinery 

 except to the 

 plunger j 



OK CONVEYING BOATS OR BARGES ON CANALS. 



Jock being now on a level with that in the upper canal, the 

 upper fluice may be raifed, and the boat floated out. The 

 plunger being ftill down, if a boat be floated into the lock from 

 the upper canal, let the upper fluice be (hut and the plunger 

 be raifed, and the boat will in like manner defcend in the 

 lock to a level with the lower canal. 



It is obvious that the principle of this invention is 

 founded on this law in hydroftatics, viz. that two columns of 

 water however different in lateral dimenfions, will, if there 

 be a communication between them, always maintain one and 

 the fame level. 



The plunger is to be counterpoifed by a weight acting on a 

 fpiral curve (on the fame fhaft with the wheels or mechanifm 

 that raife the plunger) in order to accommodate the action of 

 the counterpoife to the decreafing weight of the plunger as it 

 defcends into the refervoir ; fo that being counterpoifed it may 

 be eafily raifed or funk by means of the mechanical apparatus 

 ufually employed for fuch purpofes, poffibly indeed this move- 

 ment may alfo be effected by means of a fire-engine, but the 

 expediency of fuch means is not meant to be fuggefted. 



In theory the wall or partition common to both the lock 

 and refervoir may not be neceffary, however ufeful it may be 

 in practice. 



Should occafion require it, the refervoir may be placed at 

 any given di fiance from the lock, provided there be a com. 

 munication between them, at or near the bottom. 



Without fuggefting any precife limitation (which can be 

 learned only from experience) the projector conceives that 

 locks on this conftruction are better adapted to low or mode- 

 rate lilts than to high ones ; boats, alfo of a moderate fize (as 

 recommended by Dr. Anderlon and Mr. Fulton) and fo con- 

 ftructed as to exceed rather in depth than in length or breadth, 

 feem beft adapted to the fcheme now propofed. 



On a comparifon then between this lock and others of a late 

 invention, it is prefumed that wherever it may be expedient 

 to ufe it, it will be attended with the following material ad- 

 vantages. 



1ft. The only machinery neceflary (the two fluices ex- 

 cepted) in this lock, is for the purpofe of railing and finking 

 the plunger or plungers. 



2d. Whilft 



