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with an accelerated motion, and in all diredlions. If the orifice 

 be horizontal, that filament of particles, which anfwers to the 

 centre of the hole, will defcend in a vertical line, and will fufFer 

 no other refiftance than that of the fridlion caufed by the excefs 

 of its velocity above that of the collateral filaments, or by the 

 retardation which arifes from the attradlion fubfifting between 

 them. The other filaments, after they have defcended vertically 

 for fome time, are compelled to turn from their vertical courfe, 

 and to approach the orifice in different curves ; and when thf y 

 arrive at it, their diredtions become more or lefs horizontal, 

 according as they pafs nearer to or farther from the edge of the 

 orifice. The motion therefore is decompofed according to two 

 direiflions, the one horizontal, which is deftroyed by the equal 

 and contrary refiflance of the filaments which, are diametrically 

 oppofite; the other vertical, in proportion to which the quan- 

 tity of water difcharged is to be eftimated. Hence we fee, that 

 the vertical velocity of the filaments decreafes from the centre 

 of the orifice to its circtimference ; and that the total difcharge is 

 lefs, than if all the filaments had iflTued vertically, in the fame 

 manner with that which anfwers to the centre of the aperture. 

 It alfo follows, that the filaments which are nearer to the centre, 

 moving fafter than thofe which are nearer to the edges, the 

 vein of the fluid, after it has iffued from the orifice, will form 

 a cone whofe bafe is the orifice ; that is to fay, that its diameter 

 ryill diminifli, at leaft, to a certain diftance, becaufe the exterior 

 filaments are gradually drawn on, in confeqvience of their 



mutual 



