Monday, November 11, 2013

Counterweighting the Kiyor

I wanted to reexamine one detail from my model of the Muchni – the sturdy wooden machine which raised the Kiyor [Laver] from the well of water each morning and lowered it down again in the evening. In my model I have the Kiyor balanced by a lead counterweight hanging from the back of the Muchni and it is this weight which keeps the Muchni from tipping over and also makes it possible for a single Kohen to raise the Kiyor which, when full of water, weighed over 5,000 pounds (see the earlier post for more on this).

To perfectly balance the Kiyor a total of 5,548 pounds of lead would be required, which works out to a solid block measuring about 1 x 1 x 2 amos (18 x 18 x 36 inches). To balance the Kiyor in the afternoon (when it was empty) would require only 3,356 pounds of lead, or a block measuring about 1 x 1 x 1.25 amos (18 x 18 x 23 inches). When I first made my model I had simply guessed at the size of the counterweight but, after looking at the numbers above, it turns out that the block of lead I used is actually quite close to 3,356 pounds. So while the Muchni does offer some mechanical advantage in the gearing and pulleys, the Kohen raising the Kiyor still has to put some muscle power into it.

Here is an updated version of the animation showing the Kiyor being raised from the well of water. 

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