From a given observation point, a star found at one location in the sky will be found at nearly the same location on another night at the same sidereal time.
The third method did not use the equation of time; instead, it used stellar observations to give sidereal time, exploiting the relationship between sidereal time and solar time.
Sidereal time is time by the stars.
Later, he envisioned a clock that would show every conceivable type of time, from sidereal time to the rotation of the planets.
It is practically proportional to the sidereal time, which is also a direct measure of earth rotation.
When one moves eastward 15 in longitude, sidereal time is larger by one sidereal hour (note that it wraps around at 24 hours).
The sidereal time will be included, as well.
Using an object's right ascension and the local sidereal time it is possible to determine the time of its culmination (see hour angle).
