The time keeper chandelier, how does it work?

[michel123456]

I stumbled upon this ancient time-keeping device,The Chandelier Clock of Ibn Yūnis ,

The principle is simple, each lamp is burning a certain amount of time. You have to put in each lamp a specific quantity of oil in order to burn, the first for 2 hours, the second for 4 hours etc. With the subtility that in antiquity (& medieval times) the hour was not standard but it was a portion of daytime. When the day was short, the hours in sunlight were short & in night time were long.

Here below the description of the object

And here a couple of images

I am seeing that the lamps are not at the same height. i see they are all connected (for same air pressure? I don't understand the central container and the tubes that join the one with the other. Has anyone an idea?

Thanks

 

[michel123456]

OK

The bottles are connected with a circular pipe. The bottles are placed at different height, low and lower at regular interval. They cannot be moved because there are 2 openings in it for the horizontal pipe.

It looks to me the horizontal connecting pipe plays the role of communicating vessels. In this case the pink oil in the lamps is too low in the pictures, it should go over the horizontal pipe.

That would mean that the system is designed in such a way that all lamps have the same level of oil when filled. The lamps will burn a different amount of oil (and time) because the lamps are positioned at different height.

Now we have the radial pipes. Are they pipes? Or simply a structural hanging system. The fact that the same configuration, with a central "tank" is common to both pictures (and to a 3rd not posted here) makes me think that the radial system is made up of pipes. It means each bottle has 3 side holes (2 for the horizontal pipes + 1 for the radial)

It looks like the oil filling procedure is done by filling the central tank. The oil flows by gravity from the central tank into the bottles, equally filled because of the communicating vessel effect.

But then, why are the radial pipes connected to the central tank at mid height and to its bottom? Is this a kind of decantor?

How do you open the central tank? (it is hanged) Do you need to take the whole chandelier down?

If one fills the central tank, it may happen that the quantity inside the bottles gets much higher than expected. There is no apparent system to regulate the quantity of oil in the bottles, only that the quantity is the same.

IOW if I understand clearly the system is made to regulate the gap between the extinction of the bottles. It determines a duration, but does not determine when this duration will begin.

Any comments?

And when you fill the system, How does the air go out? I mean, the air that is in the closed bottles, does it go out through the cap of the bottle?

Edited September 2, 2017 by michel123456

[japetus]

Just bumped at this thread, and although a very old one, I'd like to share my thoughts..

This device at the picture is probably one inspired by the chandelier of Ibn Yunus, made for educational purposes in order to explain the functionality and not an exact replica.

The initial device was used to measure night time and involved 12 separate lamps in which according to the time of the year, a specific amount of oil was measured and inserted to each one of them, x at the first, 12x at the last. The mass/volume of x was determined by the time of the year and there were specific tables created for each week of the year at a specific place.. So, filling up this device was a very tedious job and this is probably why the image above shows a chandelier engineered as to work on the communicating vessels principle in order to ease the filling.

At the time of the invention, the day was divided in 24 hours, 12 daylight, 12 at night, starting from dusk till dawn and were not equal between them. Today this type of time measurement is known as Byzantine time and even nowadays some orthodox monasteries as the ones in Mt.Athos continue to use it.

The device pictured can only be used for a fixed date, and I presume is used to measure modern time, ie x equals to the oil required to burn for exactly 1 hour.