Hydraulics.

immersed with the shorter Leg *** ^ _and the Air sucked out of the Instrum

9- When A is very great in respect *> £ xpre f_

may he rejected as inconsiderable^ an ,

be «d»cea ,o ^

\/H Inches, for the Velocity of t ^ e , j anc J is easySecond. Bo, (a, Sir Ifi* N'-«S”n’p‘^ E >»"'to observe) ,hb Velocity ° »“'JÆ‘i.e itl Thethe Hole in Experiments, as * e p J, ent \v a tcr contractsReason is, because the Vein of effl 0 f about a

itself, and grows narrower to. the D , measuring,

Diameter of the Hole helow it; wh > J £ rhe

Sir Isaac found the Diameter of the Vein to that ot .HnU cbonrp the Area ot a ve,

41

!* r Isaac found the Diameter of the V ein u> w.— -- -■

«°|e as ax to 25; whence the Area of a Section of thee in there will be to the Area of the Hole as 441 to^ 2 5 , that is, as 1 to / consequently, the Veiocw

fy of the Vein is to the Area of the Hole as v/ 2 to 1m that Part, because of equal Momenta in both Cales.to. Hence, if I G = 48 Inches, and the Diameter

°f the Hole 1 Inch; then 48+X—49 Inches will bethe Height from the Place where the Velocity is great-E- Now the natural Velocities acquired by Water de-pending freely, from the Heights of 48 and 49 Inches,Areas 69 to jo, and therefore nearly equals Con-^quently, the great Inequality of 1 to 2, or thef-hminution of the Velocity in the Hole, must be ow-ln § to the Retardation occasioned by the lateral Waterre isting m f ome measure its perpendicular Descent. _

JI - Hence the Velocity of ihe Water in the Hole isvery nearly equal to that which would be acquired m de-Icending through 4 IG ; because the Velocity acquiredby descending thro' «IG is to that acquired by descend-ing through IG as" t to y'T Whence the Velocity>n jhe Hole i s to be diminished in the Ratio of 1 to^ 2 — I ? 4 1 4 > Thus, as 1,414 '• 1 : • 8,02773;,5>6?73 j and as 1,414 : 1 : . 96,33276 : 68 ’ 12? Vfthat the true Velocity of the Water in the Hole is

5 ’ 6 773 \/H Feet, or 68,1278 v/H Inches per Se-cond,

W. We