the earliest type of timekeeping device, which indicates the time of day by the position of the shadow of some object exposed to (подвергающийся воздействию)the sun's rays.
sundial
It has two round glass sections linked by a narrow (узкий) channel, and contains sand.
hourglass
a thin candle with markings (маркировки) spaced out (разбитые промежутками) that indicate how much time has passed as it burns.
candle clock
It comprises (содержит) an oscillating (колеблющийся) mechanism that marks the passing of time, and an escapement (торможение) that counts (считает) its beats (биения).
mechanical clock
a clock that uses a swinging (качающийся) weight (груз), as its timekeeping element
pendulum clock
It is powered by (работает на) a battery or solar cell (элемент солнечной батареи), in which the timekeeping is regulated by a quartz crystal that vibrates at a certain (определенной) frequency (частоте).
quartz wristwatch
ancient device for measuring time by the gradual (постепенном) flow of water
water clock
a clock that measures time by monitoring (отслеживая) the resonant (звонкий) frequency (частота) of atoms.
atomic clock