...times of their rising and setting ; and the star will not set until its zenith distance is 90° -j- horizontal refraction, and the corresponding hour...horizon, when the height of the eye is twenty feet. Dip. 2. Find the dip of the sea at the distance of 3 miles, when the height of the eye is thirty feet....

...shine on the lower layers at night, or before it has begun to shine upon them in the morning. Twilight begins and ends when the sun is about 18° below the horizon. 592. Color of the Sky. — Large particles reflect and diffuse all luminous waves equally well, but...

...shine on the lower layers at night, or before it has begun to shine upon them in the morning. Twilight begins and ends when the sun is about 18° below the horizon. 451. Color of the Sky. — Large particles reflect and diffuse all luminous waves equally well, but...

...doubtful " light which precedes the rising of the sun and follows its setting, called twilight. Twilight begins and ends when the sun is about 18° below the horizon ; and its duration, therefore varies with the latitude, for the time which is required for the sun...

...sun." Twilight. The refracted sunlight visible after the sun has set, or before it rises. Twilight begins and ends when the sun is about 18° below the horizon. On the "longest day" the sun is about 23 g° north of the celestial equator. Its zenith distance is...

...doubtful light which precedes the rising of the sun and follows its setting, called twilight. Twilight begins and ends when the sun is about 18° below the horizon, and its duration therefore varies with the latitude." To find the time, therefore, that twilight will...