Counterweight door, a self-feeding hearth, and a fortress tower
Door counterweight and pulley, garden-wall and roof coverings, and a towered fortress
A sheet of practical devices and structures. Leonardo details a counterweight for a door set at half the jamb's thickness, with the cord-gathering pulley hidden in a hollow of the cornice, and a self-feeding hearth kept always alight by wood dropping through an overhead conduit. He also notes a covering for a garden wall that cannot be dismantled and sketches a wooden roof truss, while a tall towered fortress with lesser towers rises at the right.
On this page
Counterweight for a door
A convenient counterweight for a door is described, made for when the door sits at half the thickness of the jamb (stipite). It is drawn at the top left with its weighted box.
Pulley hidden in the cornice
The pulley (girella) that gathers up the cord is concealed in a hollow within the overhang of the cornice. The related sketch shows the cord and wheel.
Undismantlable garden-wall covering
A note gives a way of making a covering for a garden wall that cannot be taken apart. It accompanies the roofing sketches on the sheet.
Towered fortress
At the right rises a tall fortress tower with lesser towers and connecting walls, a rectangular stronghold. It is the dominant drawing on the sheet.
Self-feeding hearth
A continuously fed hearth is described that always has wood and fire, because the wood descends through a conduit that drops over the middle of the hearth. It is drawn at the lower left as a conical hooded fireplace.
Wooden roof truss
At the lower right Leonardo sketches a triangular wooden roof truss with tie-beam and struts. It belongs with the sheet's roofing studies.