Was the Pascaline the first mechanical calculator?
From two letters written in 1623-24, found in Johannes Keplers papers, we know that an earlier adding machine containing a carrying mechanism must have existed. The letters were from Wilhelm Schickard (1592-1635), a professor in Oriental Languages, Mathematics and Astronomy at the University of Tbingen, Germany. In his letters to Kepler Schickard described his newly constructed calculating machine which used sprocket wheels and he explained its workings through several detailed technical drawings. It is clear from the correspondence that Schickard himself did have a working version. Although no actual copy of the Schickard machine has ever been found, his annotated sketches to Kepler made it possible to reconstruct a working replica of his calculator. This machine was featured on a West-Germany stamp in 1973 commemorating the 350th year of the Schickard calculator. The stamp shows the number 100722 (visible in the upper dials) being multiplied by 4. Although the Schickard calculator wa
