Antique of the Month - 20th Century Maritime Chronometer

The featured antique this month is another maritime one: a 20th Century maritime chronometer – and it’s Russian! I don’t have any provenance for it, nor do I have any other information about it. I would like to say this is circa 1920 but it could easily be later. It has beautiful solid wood and solid brass parts to it, yet the stamped red serial number on the clock face would seem to be later. It could easily be post-Russian, meaning Soviet Union. But would the Soviets be using solid brass parts when plain steel ones would do? That’s why my guess is 1920’s but that’s all it is, a guess. It’s true date of construction is a mystery!

Anyway, I bought it because I wanted a chronometer but they are very hard to find for purchase. This one came up so I bought it so I would have one, though, to be honest, I’d still like to find an English one because of the sea-going tradition of that country. Nevertheless, this is still a good one! I hope you enjoy the photos.

Note how maritime instruments of the day were all in boxes since they were carried aboard. Every single antique nautical instrument I have is contained in a wooden box. This chronometer has handles for carrying aboard, in this case most likely by the ship’s navigator. The hinged glass top is to be able to view the chronometer without opening it up to the elements (salt air!) that over time could foul the intricate mechanical clock machinery. I will also provide next before the pics a brief description of what a chronometer is and why it was a necessary maritime instrument for going to sea until the early 1950’s.

Before GPS, radar, or even long-range radio waves were introduced for navigation at sea, how could you tell where you were when out in the middle of the ocean with no land anywhere? Before chronometers, you could only find your latitude: imaginary horizontal lines dissecting the earth beginning at the equator. You would see the angle of the sun on the horizon and know how far “above” or “below” the equator you were. But how about how far along that line (east or west) of latitude were you? Maritime nations struggled to solve this problem for literally hundreds of years. But then one man, a clock-maker, made the discovery. He proved that if you could get a clock to work (remember, in those days all clocks were mechanical devices….you had to wind them up and a spring would wind them down) successfully amidst all of the rolling around encountered by a ship as sea, then all you had to do was know the time of the port you just departed from.

Here’s how that works. The rotates completely on its horizontal every 24 hours. Just as with horizontal latitude lines, the earth could also be carved up into a series of vertical lines. Depending on how many of these you wanted to use would dictate the time distance between (how much the earth rotated between them (take 24 hours and divide it up by the number of vertical lines). These vertical lines were called lines of Longitude. So, Latitude lines go horizontally around the earth and latitude lines go vertically around the earth.

Right as you leave port, you note the time on your chronometer. Then, let’s say four days out to sea headed on a westerly course the entire time you note the time of the sun directly overhead. Compare it to what time the chronometer shows. Then take that time difference and calculate which line of longitude you are on by simply adding up the number of longitudinal lines you’ve crossed. So it would be four days (96 hours) plus whatever the time difference is between the sun sighting at noon and the current chronometer time. Let’s say it’s six hours. Just count up the number of longitudinal lines you’ve crossed east to west from the port you departed that get you to 102 hours. That is your longitude (east-west) position. Then the angle of the sun on the horizon at noon will give you your latitude. Plot each, and “x” will mark the spot! Remember, the greatest scientific minds in the world took hundreds of years to figure out how to find longitude…and they failed. A simple clock-maker in London solved it! Note also that that “port” you’ve departed from is always going to be Greenwich, England. Heard of Greenwich Mean Time? This is it! The Royal Naval Observatory is at the top of the hill there, and at precisely 12 noon each day, all the ships in the harbor below would wait for a giant red ball on a big stick would come down at noon in order to set their ship’s chronometers to 12 noon as they prepared to sail.

There is a great movie (a drama) on this you should see about all of this, I’m sure it’s streaming somewhere. It’s called, appropriately, “Longitude,” and shows you the trials and saga of the clock-maker that solved the problem of how to find longitude. You should definitely watch it! His name was William Harrison and today his original chronometers (there were several designs as the years progressed) from the 1700s are on display at the Greenwich Royal Observatory in London, England. If you’re ever in England, it is worth a visit to see his inventions! It’s a moving experience! Note there is also a great best-selling book on this called simply, “Longitude” by Dava Sobel and the movie above is based on her book.