[ 6o ] 



on an horizontal plane, muft be lefs than that which reftilts from 

 the theory of water iffuing through an horizontal aperture. But 

 it is obvious that the greater depth of the lower particles, when 

 the orifice is vertical, cannot account for the entire difference 

 of diftance to which the particles are projeded ; for the depth 

 of the orifice being 8,55 inches, and the diameter of the orifice 

 ,08 of an inch, the velocities on account of the difference of 

 depth would be only as ^^8,55 to ^8,63, or as 14>6 to 15 

 nearly. Perhaps it might be faid, that this difference of diftance 

 was caufed,'not by the different velocities, but by the different 

 dlredlions in which the particles are difcharged ; fo that thofe 

 which are projected in the axis of the vein, will ftrike the ho- 

 rizontal plane at a greater diftance than thofe which are projedled 

 from the edges of the orifice with the fame velocity, but in a 

 different diredion. But this cannot be the caufe ; for when the 

 aperture is horizontal, the particles which iffue from the oppofite 

 fides ;k,« of the orifice (fig. 2.) meeting each other, deftroy their 

 convergence, and afterwards proceed in the diretHiion of the axis 

 of the vein, and therefore the vein will continue nearly of the 

 fame diameter : whereas, if the particles croffed each other, with 

 the fame velocity, in different dire(flions, they wovild defcribe inter- 

 feding parabolas n s, m I, and the diameter of the vein would con- 

 tinually encreafe. In order to determine whether this were the cafe, 

 I caufed the fluid to iffue through an aperture in the bottom of the 

 veffel, and at the diftance of 12 inches I found the diameter of the 

 vein a little encreafed, when the velocity of the efflux was con- 



fiderable ; 



