Benet Bvt (1 results)

Hardcover. Condition: Very Good. No Jacket. 1st Edition. Red cloth with gilt lettering on cover. Very good condition. The paper on interior front spine is split, the binding is solid. Frontispiece engraving of the Schultz Chronoscope. Three other full page engravings of the Schultz Chronoscope. 48 pages. The 1st edition is very hard to find. "Schultz Chronoscope - This instrument, invented by Captain Schultz of the French Artillery, is designed for the measuring of very short intervals of time. By means of it, periods varying from thirty seconds to the one-five thousandth part of a second have been measured with very great approximation, and with great ease and accuracy. It was introduced in the United States for the purpose of determining the initial velocity of projectiles in the proof of gunpowder. A turning-fork, caused to vibrate by electro-magnets, makes an ascertained number of vibrations per second; it traces on the surface of a revolving cylinder a sinuous line, showing the beginning and end of each vibration. This sinuous trace is an actual scale of time. The instant at which a projectile reaches any point in its trajectory is by the application of electricity marked upon the cylinder beside the scale of time. The number of vibrations comprehended between any two consecutive marks, is an exact measurement of the time elapsing between the instants at which the projectile occupied the corresponding positions in its trajectory. The measurement of time depends on the equality of duration of the vibrations in the unit of time is fixed by the construction of the fork." - Farrow's Military Encyclopaedia.