Antiquities (3)

Calculating device (1710) of the German constructors Anton Braun and Philippe Vayringe and signed: Braun invenit, Bayringe fecit. The remarkable machine was an attempt to solve the mechanical problem of smooth carrying, while adding: 9+1=10 and subtracting: 10-1=09. A similar machine was described by Jacob Leupold (1647-1727) in his Theatrum Arithmetico-Geometricum.

Astronomical clock of Giovanni de Dondi (1364), one of a family of Paduan artificers, is more complex than any built for centuries thereafter. Its array of planetary dials and complicated assemblies of circular and elliptical gears, link mechanisms and careful computation, together with its seven main dics showing the motions of the various stellar bodies, make it one of the most handsome mechanical masterpieces ever constructed. From the thirteenth century on, astrolabes, quadrants, equatoriums and automata were produced by highly developed craft of practitioners.

The so-called macaroni-box of Dorr E. Felt (1885). This wooden calculating machine was the first that could be operated by pushing buttons to input digits. Felt's source of inspiration for this adding calculator was the behaviour of a rocking-horse. In this very first model the buttons are the rods on the front which must be gently pushed or pulled.

The Millionaire (1893). The first commercially successful calculating machine to be based on Leon Bollee's principle of direct multiplication. In 1982 Otto Steiger constructed the compact Millionaire and brought to market. This machine could perform all calculations which can be made by the four operations of arithmetic. Its principle advantages were the simplicity and comparitive rapidity with which multiplications, divisions, quare roots and compound rules were treated.

Thomas Arithmometer (1851). Adding machines and arithmometers were fairly common toward the close of the nineteenth century. The procedures for multiplication  and  division were slow and indirect however, so lengthy computations were generally done with logarithmic tables. Analog devices were used for complex calculations like the tides-tables in Britain and the US.

Abi Bakr Astrolabe (1221). Replica. This geared calendar and lunar indicator is a movable star map and planetarium which can be rotated to show where all the stars are at any time of any day of the year. This replica is a fine Persian Astrolabe copied from the original at the Museum of the History of Science, Oxford, England, without doubt the oldes geared machine in existance in a complete state.

Quadrant (Ca. 1320). Replica. An instrument which consists essentially of a flat plate in the shape of a quarter of a circular disc. Equipped with a pair of sights, a quadrant could be used for measuring the angular elevations of celestial bodies and for carrying out geodetic computations. Astronomers and mathematicians of early islam appear to have been the first to develop the first forms of quadrants. It consisted of a scale along the curved edge with a plumb-line suspended from the apex of the right-scale. Using these elements one could solve problems of navigation, geography and surveying.