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It is to be observed that the cisterns are free to move only verti-cally, the rods and rear cistern walls only forward and backward,the wooden floats can shift only sidewise right and left while thelevers assume such positions as the mechanism compels.
§ 5 .
Let given quantities of water be introduced into each front-and-back-row of front cisterns and into each right-and-left row of backcisterns. The system will attain a stable equilibrium and the levelof water in each cistern will be that of the tank.
The front cisterns of a front-and-back row must have a uniformlevel on account of their mutual connection. The back cisterns ofa right-and-left row must preserve a uniform level for a similar rea-son. The movable rear walls allow the pressure of the outsidewater in the tank to keep the back cisterns at the same level as thefront. Without taking account of the levers the cisterns wouldthus all have the same level as the tank. But it would be possibleto arrange their vertical positions and their rear thicknesses in manyarbitrary ways. The levers simply specify or determine this arrange-ment.
§ 6 -
It may be needful to restate carefully the magnitudes, their unitsand the conditions which determine them. The magnitudes are:
1. The quantities of each commodity consumed by each individualduring the year. These are represented by the quantities of waterin each front compartment.
2. The given total quantities of each commodity consumed by thewhole market —represented by the fixed amount of water in eachfront and back row of front comparments and registered on scales*A, B, C, at the rear of the tank. Each commodity-water may havea distinguishing color.
3 . The money paid for each commodity by each individual —rep-resented by the water in each back compartment.
4 . The total money income of each individual —represented bythe fixed amount of water in each right-and-left row of back com-partments, and registered on scales] I. IT, III, at the right of thetank.
* The stoppers A B, C regulate this amount of water. The stoppers are eachdirectly connected with the pointers on the scales A, B, C, and so arranged thatwhen the stopper is withdrawn so that the scale reads zero, the water entirelydisappears from the cisterns.
f The stoppers I, II, III are also directly connected with pointers on the scales
i, n, hi.