. Annual report of the Board of Regents of the Smithsonian Institution. Smithsonian Institution; Smithsonian Institution. Archives; Discoveries in science. ANCIENT JjESEMERS OR STEELYARDS. 5(U It was quite similar to the other two, ])ut weighed more exactly than tht^ Clusium balance and ran up to 40 pounds. But both this and the Palermo balance are far inferior in finish. The Clusium balance prob- ably dates from the third or fourth century before Christ. Pernice's description of this balance on the archeological and metro- logical sides is exhaustive. But as a member of the developmental sei-
. Annual report of the Board of Regents of the Smithsonian Institution. Smithsonian Institution; Smithsonian Institution. Archives; Discoveries in science. ANCIENT JjESEMERS OR STEELYARDS. 5(U It was quite similar to the other two, ])ut weighed more exactly than tht^ Clusium balance and ran up to 40 pounds. But both this and the Palermo balance are far inferior in finish. The Clusium balance prob- ably dates from the third or fourth century before Christ. Pernice's description of this balance on the archeological and metro- logical sides is exhaustive. But as a member of the developmental sei-ies of those balances called desemers, it then appears that a o-reat technical advance is made over the instruments previously considered. Fu;. 2().^>r\iscuiu of GiTra;ui Costnnu natural size. TuD-liltct'iiths. I refer to the raising- of the bridge above the staff which carries the load and counterpoise. Nothing like this has been seen in any of the desemers ])i'eviously examined. Why did the Roman deface his ele- gant instrument with this uiibeautiful bridged At first sight one might be inclined to suppose that it was simply to make the num})ers show betrer. But that hypothesis will not answer. The ])ridge, with the sciil«\ might just as well have carried the load and counterpoise too. There must have been some other reason, and a good reason there is. The two prime requisites of a good balance are, as is well known, that the friction shall be as small as possible and that the equilibrium shall be stal)le wheth- er the balance is loaded or not. The center of gravity nmst, for that purpose. ])e below the point of support.' Now German desemers, as we know ])y experience, remain still when in equilibrium without os- cillating. They can not oscillate, for the moment the departure from equilibrium is sufficient to overcome friction they turn, with no tendency to return, and slide down on one side or the other, because the point of support is below the center of gravity. If a po
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