Cane hoses fixed together by leather joints enabled the diver to breathe. Steel spirals were inserted into the joints so as to prevent them from being crushed by the pressure of the water. The tubes used for breathing stuck out of the water and were held in place and protected by a dedicated floating device. CONTINUOUS COOLING DISTILLER
The characteristic feature of this alembic was a very broad condensing surface. The section in which the fire was produced was separated from the one containing the cooling water by a central section exposed to air. This system was designed to reduce the sudden change in temperature, which would damage the glass and ceramic containers. REVOLVING CRANE
This revolving crane, which had probably been seen by Leonardo on many construction sites, near stone quarries or at can excavation works, not only lifted weights but could also rotate, thereby allowing for the fast transfer of materials from one site to another. HYGROMETER
This instrument measures the moisture content of the air at the time the measurement is taken. A household name already in Leonardo’s day, it consists of scales that contain a hygroscopic substance (sponge, cotton wool) in one pan and wax in the other (wax does not absorb water.) On dry weather conditions, the scales mark zero. However, as the moisture in the air increases - and the weight of the hygroscopic substance rises accordingly -, the scales will tip towards the pan where the hygroscopic substance is.
SCREWTONGS
Leonardo applied the double screw principle to forging tongs to increase their gripping power. A large pair of tongs which are tightened by means of a screw and, further down, several trestles with a double screw tightening mechanism. DRILLING MACHINE
The double-movement drilling machine was conceived by Leonardo before his arrival in Milan. This machine made deep drilling and digging possible. It worked in the following way: the drill was driven into the ground by rotating the upper bar, while, by rotating the second bar, the drill was heaved back up without turning and it lifted out of the ground all the earth which had collected on it. DRIVE TRAIN DEVICE
A reduced friction between pivots and a gear intended to increase human power make this model an interesting example of a multi-faceted knowledge being applied to a single device. This “drive train for a cart”, in which power is transmitted to one wheel only, apparently anticipates the idea for the “differential gear”, which Leonardo highlighted in later drawings.