Antiquities (2)

Analogous rotating slide rules and digital calculating machine (1881) designed by E. Thacher. It consists of a cylindrical drum which admits of both rotary and longitudinal movement within an open metallic framework of 20 equidistant triangular bars. The bars are connected to rings.

This calculating machine (1623) is the first known mechanical calculator to add, subtract, multiply and divide. It was invented by the German math professor Wilhelm Schickard.  It remained unknown for 300 years. In 1860 it was reconstructed by Baron Bruno von Freytag-Löringhoff. Although the calculating machine was destroyed in a fire and never rebuilt, it has been reconstructed from sketches and drawings from the astronomer Johannes Keppler.

Samuel Morland's calculator (1664). The machine consists of a gilt brass plate carrying 55 numbered silver circles and 17 numbered silvered brass circles. It is housed in a wooden case with a crystal lid. It seems that the design was inspired by Napier's rods. The rods are inscribed on brass circles and these can be turned, via a crank, to show the products through a series of window-like displays.

In 1878 the Swedish engineer Wilgott T. Odhner invented and constructed a calculating machine of the 'pin wheel and cam disc' type. F. Trinks of Natalis & Co. manufactured this machine in an improved form and placed it on the market under the name Brunsviga. The machine performed the four operations of arthmetic. Brunsviga machines were continually improved and became very popular in Europe.

Charles Mahon, the Earl of Stanhope, invented this logic demonstrator (1780). A device that solved arithmetic problems in a logical form. In 1775 and 1777 Mahon made two machines, the first using the stepped gear principle of Leibniz and the second being a more complicated variant of the Leupold scheme in which the cogs were disengaged after the required number of teeth had passed. Each machine was able to perform multiplications and divisions. It dealt with numbers up to 12 digits.

Hines' Adding Machine (1850). A single-digit key-driven adding machine. Instead of using numeral wheels, readings were taken from a long ratchet-toothed bar which limited addition to a single column of figures. Drawback: no provision had been made to overcome the momentum problem so that the machine had the tendency to overshoot and yield incorrect answers.

Second calculator (1666) invented by Sir Samuel Moreland. It is similar in principle to Pascal's device. Fabricated by Humphry Adamson, one of the first makers of the pendulum clock designed by the Dutch scientist Christiaan Huygens. This machine used little wheels, each of which had a simpel projection that turned a companion wheel at each revolution. Primitive because carrying was not automatic