When hydraulic pressure to the amount of 2000 to 3000 lb per square inch is applied, the saving is unquestioned, since less time is required to dry the pressed retort, its life in the furnaces is longer, its absorption of zinc is less, and the loss of zinc by passage through its walls in the form of vapour is reduced.
The bicycle built up speed and Dean was aware that only one square inch of brake pad separated him from oblivion.
Second only to the compass in its value to the sailor is Thomson's sounding apparatus, whereby soundings can be taken in 100 fathoms by a ship steaming at 16 knots; and by the employment of piano-wire of a breaking strength of 140 tons per square inch and an iron sinker weighing only 34 lb, with a selfregistering pressure gauge, soundings can be rapidly taken in deep ocean.
Where the ratio of the length to the least transverse dimension is higher, the load per square inch shall be proportionately reduced.
The subjection of the core to a hydraulic pressure of four tons to the square inch and an electric pressure of 5000 volts from an alternating-current transformer has been adopted, by one manufacturer at least, to secure the detection of masked faults which might develop themselves after submergence.
In the wider compartments are placed sieves having sixteen holes to the square inch and bearing zinc turnings.