Tuesday, July 17, 2012

Time Keeping

We got a new clock alarm a few days ago. You don't even have to set the time. Just plug it in and it finds the time.

That got me remembering how clocks used to be. Electric clocks that plug into wall sockets have always been acurate (within my lifetime). The power company carefully maintains 60 cycle per second alternating current. An electric clock based on that will always keep good time.

I remember a news report after a blizzard in the late 1970s that warned that, due to increased power demands, the power company had allowed the cycles per second to slip by a few seconds but they would make up the extra seconds later that week.

Of course you had to set your electric clock to the right time in the first place. Radio and TV stations would give the exact time regularly or you could call the phone company. Most phone companies had a time and temperature number using some early automatic equipment and prerecorded messages.

Once you were out of the house you were on your own as far as time went.

Watches were common. There were no battery-powered watches. They all ran off of a mainspring that had to be wound.

I still have my father's watch. My mother gave it to him before I was born. It was an expensive, high-end timepiece. It was self-winding which meant that it used an internal weight and the wearer's arm movements to wind the watch. If you didn't move your arm enough the watch would wind down (although you could wind it manually). There has been a revival of self-winding watches in the last few years. They are not made as well as my father's. Undoubtedly they cost a lot less, also.

As watches from the 1950s go, this one is quite accurate. It does have to be adjusted every few days.

Timex used to have a line of kids watches. These were cheaply made and not very accurate. Typically one of these had to be adjusted daily. I remember having one that was off by around 10 minutes a day. These watches didn't last long, either. The mainspring or some other vital part would break within a year.

Larger clocks were more accurate. A lot of alarm clocks had to be wound daily but kept decent time.

The worst clocks were in cars. When a car's engine is running it is charging the battery and produces around 13.5 volts. When the engine is off the battery is discharging at around 12 volts. Electric clocks were just electric motors and the higher the voltage the faster they run. car makers tried to estimate how much time a car would be running and designed clocks based on that average. For most people this resulted in clocks that were off by several minutes per day. Even high-end cars had this problem.

In the 1970s watches based on cheap, accurate working became available. Suddenly everyone could afford an accurate watch and timekeeping was never the same.

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