River spur, weir facing, a stone auger, and fast earthworks
A breakwater against a river's force; a drill kept wet; men passing material at speed
The page treats river works and the labor that builds them. A large cross-hatched block is a spur (breakwater) set against the onrush of a river, and a note says the outer facing of fish-weirs should be of the same composite-stone nature. A parasol-shaped auger for boring stone is to be kept constantly wetted, and a group of workmen on a slope pass material rapidly from hand to hand as a way of carrying out a work with speed. Two small diagrams at the upper right show the proportional division of a line by oblique parallels.
On this page
Spur and composite-stone facing against a river
A large block of composite stones with a pointed projection is drawn as a spur set against the onrush of a river. A note adds that the outer facing (scorza) of fish-weirs ought to be of this same nature.
Auger for boring stone, kept wet
A parasol-shaped drilling device is captioned as an auger for boring a stone, with the instruction that water must always drip onto it while it works.
Passing material quickly on a slope
Several workmen ranged along a scarp pass the material rapidly from one to the next, illustrating a way of carrying out a work with speed.
Proportional division of a line by parallels
Two small diagrams at the upper right show a base line divided proportionally by a set of oblique parallels.