(5 30 Mr. U ANN’S freatife 
fhews, as nearly as poflible, what the true time of paf- 
fage ought regularly to be when nothing happens to dif- 
turb it. 
It is alfo highly worthy of remark, that the mean 
results contained in this laft column form a feries of num- 
bers regularly increafing as the depths of water, wherein 
the refpeclive experiments were made, regularly deer cafe', 
fo that the different velocities of the floating body are in an 
inverfe ratio of the refpeffive depths of the water in which 
it floats with an equal impulflve force , and that according 
to the law of the above feries. This, perhaps, may fur- 
nifh elements to calculate, pretty near the truth, the dif- 
ferent velocities of veffels upon canals and rivers w ith, 
different depths of water in all other cafes whatibever. 
As to the conclufions to be drawn therefrom in practice, 
and in the common ufes of life, they are too obvious to 
need mentioning here. 
SECTION V. 
On the quantitity of declivity in rivers. 
62. Abftradting from all refiftance and friftion, fluids, 
fuch as water, defeend upon planes let them be never fo 
little inclined towards the center of the earth : and the 
5 velocity 
