2. A skyrocket that has a spiral flight: At the yearly firework display, Jack and Jill watched the tourbillon emitting bright lights up high in the air.
3. An ornamental firework which turns around, when in the air, so as to form a scroll of fire: The crowd watched the tourbillon that gyrated in the air.
4. Etymology: "whirlwind; firework" with a spiral flight; from French tourbillon, "whirlwind"; from Old French torbeillon, ultimately from Latin turbo-, "whirl, whirlwind"; genitive of turbinis, "whirlwind".
5. In horology, a frame for the escapement (a device which converts continuous rotational motion into an oscillating or back and forth motion) of a timepiece, especially in an epicycle and assumes all the vertical positions in one or two minutes; therefore, minimizing or neutralizing position errors.
The tourbillon is one of the most valued features of collectors' watches and premium timepieces, possibly for the same reason that mechanical watches obtain a much higher price than similar quartz watches that are much more accurate.
High-quality tourbillon wristwatches, which are usually made by the Swiss luxury watch industry, are very expensive, and typically retail for prices in the tens of thousands of dollars or euros being common, for example, a "Reverso Gyrotourbillon 2" (a spherical tourbillon) watch by Jaeger-LeCoutre sells for about $400,000, or more.
Single and multi-axis tourbillons aim to counter the distorting effect of gravity on a watch by rotating its escapement mechanism on one plane in a single tourbillon or three-dimensionally in a multi-axis complication.
The function of the tourbillon is to make the watch run more consistently, but it does not improve the inherent time-keeping accuracy of the watch.
In fact, as energy is required to rotate the tourbillon cage, most tourbillon mechanisms incorporate small balance wheels to compensate for the energy loss, which is actually detrimental to the precision of the watch.
Etymology: from Anglo-French turbeillun; which came from Latin turbin-, turbo-, "whirl, whirlwind".