Practical Uses
Hourglasses were an early dependable, reusable and accurate measure of time. The rate of flow of the sand is independent of the depth in the upper reservoir, and the instrument will not freeze in cold weather.
From the 15th century onwards, they were being used in a range of applications at sea, in the church, in industry and in cookery.
During the voyage of Ferdinand Magellan around the globe, his vessels kept 18 hourglasses per ship. It was the job of a ship's page to turn the hourglasses and thus provide the times for the ship's log. Noon was the reference time for navigation, which did not depend on the glass, as the sun would be at its zenith. More than one hourglass was sometimes fixed in a frame, each with a different running time, for example 1 hour, 45 minutes, 30 minutes, and 15 minutes.
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Famous quotes containing the word practical:
“As for Clothing, to come at once to the practical part of the question, perhaps we are led oftener by the love of novelty and a regard for the opinions of men, in procuring it, than by a true utility.”
—Henry David Thoreau (1817–1862)
“The idealists dream and the dream is told, and the practical men listen and ponder and bring back the truth and apply it to human life, and progress and growth and higher human ideals come into being and so the world moves ever on.”
—Anna Howard Shaw (1847–1919)