I did a fast restore on this grandfather clock. I dont see many one handers so I believed I might do a fast article on them explaining… properly, why they solely have one hand.!
Earlier than the invention of the pendulum , most clocks solely had one hand and had been regulated by a factor known as a lever escapement which was in flip regulated by a fly wheel or balanced weights going backwards and forwards on a spring. The hyperlink under is from the turret clock in Salisbury cathederal which was put in in round 1386 – 300 years earlier than the pendulum clock was invented.
If you wish to take a look on the Salisbury clock please observe the wikipedia hyperlink under.
https://commons.wikimedia.org/wiki/File:Salisbury_Cathedral,_medieval_clock.JPG#/media/File:Salisbury_Cathedral,_medieval_clock.JPG
The purpose about this weighted regulation on a spring is that it was terribly inaccurate as a result of the oscillation of the weights regulating the clock general was not notably constant.
By about 165o clocks weren’t anticipated to run on an accuracy of quarter of an hour a day. On that foundation there was no level in making an attempt so as to add a minute hand because the clocks regulation was not correct sufficient to make minute measurement helpful.
So, alongside got here Christian Huygens and upset all the apple cart by attaching a pendulum because the regulating gadget.
Now, in case you dont know, a pendulum will at all times swing on the similar fee on the identical arc offering it isn’t slowed down by friction (which after all it’s). The escapement wheel is designed to push the anchor on the prime of the pendulum simply sufficient to counter this friction and preserve the clock in perpetual movement whereas its spring or weight is making use of power.
Its an excellent system as a result of its low cost to supply and straightforward to regulate. The one different choice up till the nineteenth century was to make use of a platform escapement which to all intents and functions is what you can see in a mechanical watch. These put on out, can solely be adjusted withing sure limits, and they’re fragile. All this meant {that a} fairly priced correct clock made between 1658 and round 1960 makes use of a pendulum for regulation.
The issue with the “new fangled” pendulum clock within the first few years of its manufacturing is that it was so correct it was doable so as to add an correct minute hand. This may seem to be an amazing enchancment however truly the largely illiterate inhabitants didn’t perceive easy methods to learn two arms. They had been used to only a clock face with one hand and studying what time it was to the closest quarter of an hour. Think about if we lived in a world the place all the pieces timed, e.g. conferences, occasions, scheduled duties, was solely deliberate to the closest quarter of an hour!.
So from 1658 to about 1700 the vast majority of clock had been produced with simply the one hand. Two handed clocks did seem throughout this era however the majority had been single handed. By 1700 two handed clocks had been being bought BUT they nonetheless had the one handed markings. In case you see a grandfather clock that has each minute markers on the outer chapter ring AND quarter hour markers on the internal ring then its was nearly definitely made between 1690 and 1720 though some makers endured with twin marked faces up till 1740.
Observe additionally the half hour markers which, once more, made it by means of to the 2 handed model however had been marked for the second hand and seven.5 minutes, 22.5, 37.5 and 52.5 minutes.
An instance of a clock head (my very own John Mason London Clock) under. Observe that the chapter ring seems to be metal – it isn’t, it’s a slivered brass chapter ring produced by a silvering course of that predates any sort of electroplating by a few hundred years. The black letters are crammed with wax – in case you doubt the autheniticity of a 1700 clock test to see if the roman numerals have been carved in after which crammed with a black wax which needs to be cracking a bit and presumably the odd flake lacking.
The clock under is a John Taylor clock from about 1680 -1700 and as you’ll be able to see it simply has the one hand and the internal chapter ring marks, which at first look appear to be minute markers for a second hand, however are after all quarter hour markers for this single handed clock.
By the way the opposite factor that dates this clock to the interval is the dearth of an arch over the dial. These had been widespread after 1700 so together with the one handed format we will take guess (with out wanting up issues!) that this clock was produced inside the dates beforehand talked about.
Heres an image of the entire clock.
