Balance of Wisdom: A Mechanical Balance From the 12th Century

The “Balance of Wisdom” (or “comprehensive balance) is a name for one of the most sophisticated and advanced balances designed and manufactured after the establishment of Islam. Designer of this balance is Abdol Rahmaan Al-Khazini who also presented this balance in a book titled “Al-Kitab Mizan Al-Hikma “or “The Balance of Wisdom”. Of the prominences of this balance to others, one can point out; its precision, triple complex action, number of pans, which enabled the balance to be applied for recognition of constituent substances of twofold alloys, and their weight percentage in the alloy. It was also capable of measuring the weight and density of substances or alloys, precisely. It was mainly used at the treasuries of kings to have control upon the treasurer, by measuring the gold carat of the items kept in the treasury. The balance is a hydrostatic balance of standard form with five scale pans, a rather complicated polyfilar suspension, and a sensitive indicator tongue. It was first designed and manufactured in the twelfth century A.C, after which there are no signs of remanufacturing, or development of this balance. The balance was redesigned according to the book, “Al-Kitab Mizan Al-Hikma “, manufactured and tested as a part of a research project called “Designing and manufacturing of innovations and inventions of the Iranian scientist”, undertaken by the Mechanical Engineering Research Center of the Iranian Research Organization for Science and Technology (IROST).