This presentation is an english activity.

1. Watch
BY HRITIK JHA

2. History
• The watch which developed from the 16th century to the mid 20th century
was a mechanical device, powered by winding a mainspring which turned
gears and then moved the hands, and kept time with a rotating balance
wheel.
• During the 1980s quartz watches took over the market from mechanical
watches, an event referred to as the ”quartz crisis” because it ran on
electricity and kept time with a vibrating quartz crystal.

3. Inventor
• Nuremberg clockmaker Peter Henlein (1485-1542) is often credited as the
inventor of the watch. He was one of the first German craftsmen who made
"clock-watches", ornamental timepieces worn as pendants, which were the
first timepieces to be worn on the body.

4. The first mechanical watch
• The Pomander Watch is the oldest mechanical watch ever recorded in history. It
functions like the modern watch today with 12 hours on the dial indicated by the
hand.
• Case: copper, gold-plated on the outside, silver-plated on the inside, 45 mm in
diameter, 38.5 grams in weight, three feet on the bottom
• Movement: 36 mm in diameter, 54.1 grams in weight, iron, hour wheel with four
teeth, upper plate skeletonized, chain and fusée, regulating arm with holes for 2
hog's hairs, approx. 12-hour power reserve
• Function: Hour shown by one hand

5. How the modern day method to check time
came to be
• It was only in 1885 that the international system of units set GMT (Greenwich
Mean Time) as the standard for the rest of the world.
• It is not yet known as to why numbers till 12 and multiple of five are used to
calculate the exact time but it goes back to Egyptians dividing their day into 12 small
parts in their sundials.
• Minutes and seconds, however, were not used for everyday timekeeping until many
centuries.
• Clock displays divided the hour into halves, thirds, quarters and sometimes even 12
parts, but never by 60. In fact, the hour was not commonly understood to be the
duration of 60 minutes.

6. Why was there a need of a watch
• Explorers needed the time to navigate at sea. The latitude could already be
accurately determined on the basis of the stars, but for the longitude was the
local time needed. If the clock was one minute wrong, that was already a
deviation of 28 km in the tropics. So the origin of the watch stemmed from
the need for a precise navigation tool.