The first English stepped drum machine (it was a Thomas de Colmar-type arithmometer) was devised around 1880 by Samuel Tate (1840-1917), an iron worker and mechanical engineer from Sedgley, Staffordshire. In 1879 the Prudential Assurance Company challenged English makers to produce a more reliable machine than that of Thomas. The engineer Samuel Tate of Clerkenwell Close in Middlesex County also set out to make a simpler, faster, sturdier, and more accurate arithmometer. Tate left a Provisional Specification of his device at the British Patent Office on 29 March 1881, then made some improvements in the construction and provided complete specification (see Specification Nr. 65, 1 January 1884).
In 1883 the brothers Charles and Edwin James Layton (1850-1929), booksellers and authors of insurance books, presented the first arithmometer as the agents of Tate. Later they exhibited it at the International Inventions Exhibition held in London in 1885, and soon afterwards acquired the patents, arranging a manufacturing workshop on Farrington Road in London. Layton brothers mainly occupied themselves with printing actuary tables and insurance related items, but were really “Jacks-of-all-trade”, because they invented the printed and embossed greeting card in the 1860s, and obviously they thought that with their connections in the insurance industry, it was a good idea to have a calculating machine on offer. It turns out they were right.
Tate’s patent helped immensely, however, in early 1900s, Charles Layton patented improvements to the calculating machine under his own name (patent GB190327364), namely a direction switch on the righthand side of the machine, which facilitated shortened multiplication without having to reach over to the direction switch on the left side of the top plate, and “Tate’s arithmometer” changes to “Tate’s improved arithmometer”. Later two other patents were granted (GB190908984 and GB190912032), the machine got an input control register below the setting sliders, and was named “Layton’s improved arithmometer”.
Tate-Layton’s machines are generally considered to be the heaviest duty and best made of all of the late 19th century arithmometers. They were primarily manufactured for use by the insurance industry. Production of the device continued for more than 30 years until 1914. It seems some 1500 copies were sold, quite an achievement for a machine as expensive as this one (its price was Fifty Guineas in 1889, a large sum for the time)!
The machine of Tate is very similar to the machine of Colmar (one of Colmar’s patents is mentioned in its specification), with overall dimensions: 16.5 cm x 63.5 cm x 19 cm, and was manufactured by brass and wood (beautiful mahogany box with brass corner straps and carrying handles), with removable handle. The device is one of the most solidly arithmometers ever built, the sheer size and weight of all the elements of the construction are impressive.
The machine of Tate has a brass top and metal mechanism and fits into a mahogany case. Six (or more, e.g. eight, as it can be seen on the lower image machine) levers are used to set digits, with a stepped drum below each lever. The plate that covers the drums and top of the machine has slits in it to allow these and other parts to move. The edges of the slits next to digit levers are numbered from 0 to 9 to indicate the digit entered. An ADD MULT / SUB DIV lever is left of the digit levers, but the machine has no windows to show the number set up. The crank on the right side operates the machine.
Behind the levers moves a carriage with a row of nine windows for the revolution register and a row of 12 (or more) windows for the result register. The discs in the revolution register have the digits from 1 to 8 in red and from 0 to 9 in black. The discs of the result register have only the digits from 0 to 9. Rotating the crank on the right side of the carriage zeroes these registers. A handle for lifting the carriage is on its left. Three brass decimal markers fit in holes between the levers and windows. Thumbscrews in the revolution and result registers can be used to set numbers. Handles at both ends of the case assist in lifting.