Clocks through Time It took human being a long time to invent diverse ways for telling time. About 3000 years ago people firs

Clocks through Time
   It was probably around 3,000 years ago that people first began making things to help them measure the passage of time. Having observed that shadows move around trees as the sun moves across the sky, someone drew a circle and put a stick in the center.  As the sun passed overhead, he marked even divisions on the circle as the shadow of the stick crossed it. Then people could tell which part of the day it was by noticing which mark on the circle the shadow fell across. These circles were called "sundials." Later, they were made of stone and metal to last longer.
   Of course, a sundial did not work at night or on cloudy days. So men kept inventing other ways to keep track of time. One invention was a striped candle. Each stripe took the same amount of time to melt. If each stripe melted in a- bout an hour, about three hours would have passed when three stripes melted. A water clock was another way to tell time. A container had a line with a number beside it for every hour. It also had a tiny hole in the bottom. The contain- er was filled with water that dripped through the hole. When the water level reached the first line, people knew that an hour had passed. Each time the water level fell to another line, one more hour had passed. Candles and water clocks helped people know how much time had gone by. But candles had to be remade, and water clocks had to be refilled. So, after glass blowing was invented, the hourglass came into use. Glass bulbs were joined by a narrow tunnel of glass, and fine, dry sand was placed in the top bulb. The hourglass was easy to use, but it had to be turned over every hour so the sand could flow again.
   It was about 600 years ago that the first clock with a face and an hour hand was made.  One of the first such clocks was built for a king of France and placed in a tower of the royal palace. The clock did not show minutes or seconds. Usually it did not even show the correct hour! Since there were no planes or trains to catch, however, people were not concerned about knowing the exact time. Gradually, clocks began to be popular. They still did not keep correct time, but they were unusual, and they could be beautifully decorated. One clock was in the shape of a cart with a horse and, driver.  One of the wheels was the face of the clock. Watches came into use as soon as clocks were made small enough to be carried. These did not always tell the correct time, either. They were often put into beautiful watchcases, which were made to look like anything the owner wanted.
   The pendulum clock was invented in 1657. This was the beginning of the style of clocks we call "grandfather clocks," which were enclosed in tall wooden boxes. Pendulum clocks showed the hours more exactly than earlier clocks, since the weight on the pendulum could be moved up or down to make the clock go faster or slower. About forty years later, minute and second hands were put on some clocks. Grandfather clocks are very much in demand again today. They are usually very expensive, however, and re- quire more space than other styles of clocks. As people began to go to more places and do more things, they were more interested in knowing the correct time. By 1900, almost every house had a clock, and nearly every well-dressed gentleman wore a watch on a chain tucked in his vest pocket.
   Today, of course, we have electric clocks that keep giving the right time until they are unplugged or the electrici- ty goes off. Scientists have invented clocks that look like large machines and tell the correct time to a split second. The most modem corporate clocks for home use do not have faces or hands; These clocks are called digital clocks, and they tell the time with a set of numerals which appear in a little window. The seconds are counted off like the tenths of a mile on the odometer of a car. Many electric clocks are combined with radios, which can sometimes be set to turn on automatically. Thus, instead of an alarm ringing in your ear in the morning, you can hear soft music playing when it is time to get up. Some clocks will even start the coffee maker!
   Although clocks and watches play an important part in people’s lives in industrialized countries, time is still regarded in very different ways in different parts of the world. In the next selection, we will talk about attitudes toward time in different cultures.