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:
“The English masses are lovable: they are kind, decent, tolerant, practical and not stupid. The tragedy is that there are too many of them, and that they are aimless, having outgrown the servile functions for which they were encouraged to multiply. One day these huge crowds will have to seize power because there will be nothing else for them to do, and yet they neither demand power nor are ready to make use of it; they will learn only to be bored in a new way.”
—Cyril Connolly (1903–1974)
“And so we ask for peace for the gods of our fathers, for the gods of our native land. It is reasonable that whatever each of us worships is really to be considered one and the same. We gaze up at the same stars, the sky covers us all, the same universe compasses us. What does it matter what practical systems we adopt in our search for the truth. Not by one avenue only can we arrive at so tremendous a secret.”
—Quintus Aurelius Symmachus (A.D. c. 340–402)