348 CANAL L0GK9. 



Improvement 0"S of Others, and particularly the fly pivots when in 

 and simplifica- want of oil. 



striking part of Second — That the interval between the strokes is uni- 

 clocks. Ibrmly the same: the case is very different in other 



clocks, for as they get foul they always strik« slower, 

 and more so still when the weather is cold., 



Third — That in consequence of its simplicity, it is not 

 liable to be out of repair. 



Fourth — That it can be manufactured for considerably 

 less expense. 



HENRY WARD. 



III. 



Descnption of a Model, for elevating and depressing 

 Wetter, applicable to the use of Canal Lochs, and for 

 preventing the usual ziastc of Water therein, zcith Di^ 

 rections for working the same. By Mr, R, Salmon*. 



Improvement JLN Plate X. C is supposed to represent a canal lock of 



to save water the common construction, whose lower e;ates i. z, open 

 m canal locks. ,. ^,,,. ,, 



towards or into the lock, and its upper gates k, k, open 



towards the upper or higher level of the canal; Disa 

 hollow caisson, or water-tight chest, which is fitted to a 

 walled chamber or side-lock, so as to move freely up and 

 doM^n therein ; i is an opening, which forms a connection 

 between the lock and the caisson-chamber, and which 

 can be closed by a shuttle fitted thereto, when required. 

 Four standards, e, e, e, e, are firmly fixed on the ground 

 and walls of the lock and chamber ; and four posts, c,c,c,c, 

 are fixed m the four corners of the caisson ; on each al- 

 ternate pair of these standards and posts the frames a and 

 b rest, as on so many fulcrums, or moveable joints ; the 

 frame b fFig. 1 and 2) has two straight parallel bars of 

 thin iron fixed thereto, and standing up abote the same; 

 the frame a has two similar bars affixed to it, except that 



* From the Transactions of the Society of Arts, Vol XXIII. 

 Thtf Silver Medal was awarded for this commuuieation. 



the 



