The earliest organ, developed
by Greek inventor Ctesibius in the 3rd century BC, was used in ancient
Rome and Byzantium. It used a chamber of water
to maintain constant air pressure. Bellows-type organs, which also had
been known to the ancient world, reappeared in Europe in the 8th and 9th
The mirror was on one end of a pole, a lead weight
which weighed the same as the mirror to counterbalance it on the other.
The idea presumably was that the mirror would adjust easily to the height
of different customers. But Cstebios noticed something strange. He had
the lead counter-balance weight running inside a tube - perhaps to stop
it swinging about. But when the weight went up and down, it sometimes
made a strange whistling noise as the air escaped.This got Cstebios thinking
- both about the power of air, and about musical instruments.
Ctesibios had invented a sort of pump and wanted to connect it to a wind instrument to make the first organ. But there was a problem. Ctesibios wanted continuous sound, but with his pump, the organ only played a sound when the piston was moved in the cylinder and the pump takes as long to breathe in for just as long as it breathes out. Ctesibios solved the problem with the power of water.
Ctesibios placed an upturned bucket in some water and pushed down on it. When he pulled the bucket out, he noticed it wasn't completely wet inside. Some people have suggested that Ctesibios was the first to notice this - proving that the air is really something. He certainly realised that air was being stored in the bucket under pressure. So instead of connecting the pump to the organ, he connected it to the bucket. As air is forced into the bucket, water rises in the bowl. The organ is also connected to the bucket. This device came to be called the Hydraulis, or water-organ.
Usually, the pump can only produce air under
pressure while it is pumping. But by using the air to raise water
the bowl, the air is kept under pressure by the water even when the pump is breathing in. Of course the pump has to supply all the air the organ uses in the end, but if you can build a big enough pump, then a that isn't a problem. The amazing thing is that if you think about it, Ctesibios invented the organ itself. His machine was played by keys operating valves to let air into the organ pipes, and was powered by a pump with this water chamber - giving a continuous sound. That is by definition an organ, and such an instrument couldn't have
been made without Ctesibios.
Measuring time hasn't always been as important as it seems to be to us. Partly that's because, in the past, people's lives were governed more by nature - and partly because there simply wasn't the technology to accurately measure time. Ctesibios changed all that by transforming a legal gadget into a clock so accurate it wasn't surpassed until the 1500s. In the courts in Alexandra, you were allowed to speak for a certain regulated time when defending yourself, although the time varied - less for parking your chariot on a double-yellow line, more for murder and so on. The device they used to ensure fairness was the Klepshydra. The name means 'captured water' and it is very simple - a jar with a hole. You put the measured amount of water in, and the defendent could speak until the water ran out. Very simple, very fair - but not, Ctesibios realised, very precise. He clearly wanted to transform the Klepshydra from a device for indicating the end of a given time, into a continuously working clock. The idea of water dripping through a hole appealed to Cstebios. But the problem is this: the water drips out faster when the jar is full, than when it is empty. So although each parking ticket defendent gets the same time in the dock, the Klepshydra wasn't any good for displaying time during the day. Ctesibios had a simple solution: make sure the jar is always full.
He introduced a second container
with a bigger hole, that dripped faster, making sure the Klepshydra was
always full and so dripped at a constant rate. Of course a Klepshydra
that never emptied was pretty useless, so he had to find a way to count
the drips, or at least measure the water that came out, and he used
a float with a pointer, in a third container. Of course eventually there
was a more accurate clock. Mechanical clocks using falling weights instead
of water appeared in the 14th century, and when Galileo
described the pendulum in the 16th century, the ingredients for the modern
clock were in place. But it wasn't until 1657 that Dutch physicist Christiaan
Huygens showed how a pendulum could be used to regulate a clock. And his
was the first mechanical clock more accurate than that of Ctesibios - invented
about 1800 years before.