Nautical Decor and Replica Made from classic French admirality glass, this heavyweight Authentic Models Bronzed 30 Minute Hourglass on Stand is a wonderful nautical accessory for any sophisticated study or gentleman's library. With its beautiful tapered columned stand ensuring the ...Nautical Decor and Replica Made from classic French admirality glass, this heavyweight Authentic Models Bronzed 30 Minute Hourglass on Stand is a wonderful nautical accessory for any sophisticated study or gentleman's library. With its beautiful tapered columned stand ensuring the glass is shown off to perfection, and its clever gimbaled construction allowing for easy turning, it is a wonderful working replica and piece of decor.
A crew divided into three groups worked 4-hour shifts. Before the invention of the clock a 30-minute hourglass placed next to the helmsman was turned each time the sand ran through. After the eighth glass he would ring it eight times, and that was the signal to change shifts.
Measuring Longitude The hourglass could also be used to measure longitude. Sextants would measure the latitude, and hourglasses would be used to measure the time to find the longitude as parallel to the equator. Just imagine: if you're sailing east from Cape Town to Australia you don't want to end up on the infamous reefs out there.
The galleons wrecked on the Western Australian reefs reminded the crew of the perils of incorrectly kept time, and the major importance of the hourglass.