Atmos Clock by- LeCoultre -a Swiss made gilt brass case, Model# 528-8, Serial# 364698, dating@1960. It has white round dial with gilt Arabic numerals and ears. The hands are blued at the end to read the time easily. Atmos clocks are also known as self- winding clock because it does not require hand winding. It gets the energy to run from temperature and atmospheric pressure changes. On the back side of the movement a chamber is mounted which has internal hermetically sealed metal bellows which contains a mixture of liquid & gas (ethyl chloride). With the change in temperature or pressure it expands and contracts and keeps on winding the mainspring. A temperature variation of only 1 degree (between 15-30 degree C) or a pressure variation of 3mmHg can provide energy for 2-days operation. To run the clock on this small amount of energy everything in the clock should be friction free as possible. For timekeeping it uses a rotating pendulum, which consumes very less energy than an ordinary pendulum. The torsion pendulum’s slow oscillation make the clock very attractive and restful to watch.