A Matter of Time

Keeping Time - Clocks - People Being Telling Time

“Hide not your talents. They for use were made. What’s a sundial in the shade?”. Benjamin Franklin

Imagine what life would be like without any clocks at all. Essentially, there would only be day and night.  When man first became interested in keeping track of time, he turned to the first natural clock available: the sun.  Though night was considered to be a different and possibly dangerous phenomenon, daytime, thanks to the sun, was considered to be both friendlier and more utilitarian and it could also be measured. The shadows that the sun cast were first harnessed by the Egyptians while designing a device to count hours. A stake called a gnomon, named for the Greek word “to know,” was placed upright in the ground. The higher the sun was overhead, the shorter the shadow would be; it lengthened both in the morning and toward the end of the day. When the sun was in the east, the shadow it cast fell to the west, and vice versa; so, both size and direction of the shadow were factors in determining the time. By slanting the gnomon, people could compensate for the fact that days were not all the same length, but rather longer in the summer.  Such techniques kept their calculations accurate. Sundials were the main tool used to measure time right up until the beginning of the Renaissance in the fourteenth century.

The major shortcoming with sundials was that they required the sun. This made them useless when it was cloudy, at night, or while inside a building. Water clocks were the next major invention, but fault could easily be found with them as well.  Precise water levels were marked off in a jar that was filled by water trickling into it from another jar above it.  Despite the accuracy of the markings and the timings associated with them, there was no way to account for the inaccuracies that occurred when water froze or evaporated too quickly so water clocks soon fell into disfavor.

Sandglasses came next. They worked well when trying to determine short periods of time, but it was very difficult to find one that could last through the night, and people generally didn’t wake up in the middle of the night to flip the sandglass over at precisely the right time.  Sandglasses were also used for a myriad of other things from measuring cooking times to measuring the length of sermons and lectures.  They were also used by sailors to measure the speed of their ship.  A long rope was knotted every 47 ¼ feet and thrown over the stern of the boat.  Sailors then pulled the rope back onto the ship while the sandglass measured how long it took them to do so.  If they pulled 47 ¼ feet of rope (on knot’s worth) back onto the ship in 28 seconds, the ship was traveling at a speed of 1 nautical mile (or one knot) per hour.

The main problem with both of these methods was that they relied upon the flow of something, water or sand, to count and track time.

Harnessing the power of fire was the next step man took as he traveled through the evolution of time measuring devices.  Scholars observed that if the rate that a candle burned could be determined, then candles of uniform width with horizontal markings on them could be used to measure how much time had passed.   And so, the concept of candle clocks was born.  Once nice thing about candle clocks was that, unlike sundials, these measuring devices could be used inside as well as at night just as well as they could outside during the day.

Despite all of these attempts at improvement, the sundial was still the most widely used tool for measuring time right up until the fourteenth century when mechanical clockwork devices took over.  The tools used to measure time may have changed dramatically over the last 4000 years, but the search for easier to use and more accurate devices still goes on.

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