Antique Comptometer or Adder, Working Fine. USA, 1930s

This lovely calculator is a comptometer, also known as adding machine. This is the ST (Super Totalizer) model, made in the USA for the French market in the 1930s. The machine is designed to add quantities. As well as being a really beautiful piece, this comptometer is still fully functional. It comes in its original black-enameled metal case and a well-preserved instruction leaflet.The comptometer was the first commercially successful key-driven mechanical calculator that competed with the classic pinwheel designs of the time. It was patented in the USA by Dorr E. Felt, in 1887. From the late 19th century until the mid 1970s, millions of units were made: the design kept on being improved over the years. The machine that we can see in these images is the ST model with the Comptometer logo engraved in the front and back panels.This model has ten columns of nine keys each, made of white and black bakelite. It also has a red release key and two display output registers with two additional levers that allow for the creation of intermediate results. These features make the difference between the ST models and the ones launched before. The box bears the engraved serial number: 218097 and a small plate with the brand logo and the manufacturers name, Felt & Tarrant Mfg. Co., Chicago. This name is also printed in golden lettering in the black metal case, together with a funny inscription: Comptometer - Pronounced like thermometer.Every lover of technical and scientific antiques will find a treasure in this curious antique comptometer, antique and functional.Measurements: Width: 9.4 in / 24 cm. Depth: 14.5 in / 37 cm. Height: 3.9 in / 10 cm.