Water issuing under pressure from spouts
Width, depth and head of water in jets, a seeded glass cell to track flow, and a note on nozzles
Nine linked studies of water issuing under pressure. The writer reasons that among spouts of equal shape the widest throws its water farthest, that a spout set deeper below the surface is pressed harder and so drives farther, and that doubling the head of water more than doubles the flow, since each lower 'ounce' now bears a doubled weight. He proposes an experiment — two square glass plates sealed a knife's-breadth apart, filled with seeded water and pierced below — to watch which water runs fastest to the exit, asks how much of a body of water leans on the wall and how much presses the bottom, and concludes that nozzles should be widened across the front rather than in depth. A column of figures is jotted in the lower corner.
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Wider spouts throw water farther
Among spouts of equal shape but various width, whose centres are equally low, the one of greater shape throws its water farthest; yet the distance of the centres of their percussion is in all equally remote from the spout.
Pressure grows with the depth of the spout
For the lettered vessels b n a m: though spout n m and spout o p have their centres equally far below the surface b, their lower edges differ. The lower edge of the greater spout lies deeper, is more weighed upon by the water pressing it, and so drives the lower part of its water farther than the smaller spout does.
Doubling the head more than doubles the flow
For the waterfall a b c: a doubled height above the water's support yields more than double the water. The lower ounce, first pressed by the weight of one ounce, is pressed by two when another is added above; its weight is doubled, and with it the motion in velocity, in space and in abundance of water.
A seeded glass cell to track the flow
Take two square glass plates a quarter-braccio wide, set them a knife's-back apart, and seal three edges with wax. Fill through the fourth side with clear water strewn with small floating seeds, then pierce the bottom and give the water exit; the motion of the seeds reveals which water runs fastest to the outlet and from what site it moves.
Water's force on the wall and on the bottom
For a body of water of a given quantity and figure, it is asked how much of it leans upon the containing wall and how much of it presses with force upon the bottom.
A column of figures
In the lower-right corner a column of numbers is jotted — hundreds and smaller sums (100, 100, 100, 55, 600, 70, 445, 155, 20, 445) — apparently a running calculation.