Counterweight and pulley on an incline, and a water-wheel
The screw as the example of lightening an axle's end; measuring the water's force on the wheel's spokes
The upper note states that the more one end of an axle is lightened, the heavier the load drawn upon it becomes, and takes the screw as its example; a counterweight, a pulley and a weight on an inclined plane are drawn to illustrate the principle. A second note treats a water-wheel labelled r, f, n, g, holding that the whole power of the water striking the three spokes of the wheel should be measured at the spoke f g. Screw, drum and framework mechanisms are sketched across the upper half of the sheet, with a row of vane-like forms below.
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Lightening an axle's end: the screw principle
Leonardo argues that the more one of the two ends of an axle is lightened, the more the load drawn upon it is made heavy, and cites the screw as the example of this. A counterweight, a pulley and a weight resting on an inclined plane accompany the statement.
Measuring the water's power on the spokes r, f, n, g
For a water-wheel whose members are labelled r, f, n, g, the note holds that the whole power of the water striking the three spokes of the wheel must be measured in the spoke f g. It reduces the wheel's drive to the force borne by a single spoke.
Screw-and-drum and framed box mechanisms
At the upper right a drum is mounted on a vertical threaded screw crossed by a bar, and at the upper left a mechanism is set within a boxed frame. Below runs a strip of repeated vane- or bucket-like forms.