Everything should be made as simple as possible, but not simpler.
Albert Einstein
Several people experimented with versions of simple mechanical calculators, that included strips of metal with numbers marked on them mounted in a frame, where a stylus was used to slide these strips up and down. Let’s mention only Claude Perrault, who invented the first form of this class of devices around 1670, and César Caze, who created his version at the beginning of the 1700s. One problem with Caze’s machine was that it wasn’t possible to perform carries from one column to another. This issue was solved in 1846 by a German musician and amateur mechanic, working in St. Peterburg, Russia—Heinrich Kummer, then by Billiard in Paris (Brevet d’invention N° 6703 from 1847), and others.
In the first review of Kummer’s adding device was mentioned, that the main idea the inventor borrowed from Slominski’s adding device (in his first presentation Kummer mentioned the adders of Roth and Slonimski), which had already been presented to the Russian Academy of Sciences in St. Peterburg previous year, 1845. In fact, the internal mechanism of the device of Kummer, which went down in the history of computing facilities as Kummer’s Calculator (Счислитель Куммера), is totally different, moreover, it appeared to be considerably more cheap and effective, than the adding device of Slonimski.
On 4 September 1846, Kummer presented to the Russian Academy of Sciences his slide adder. The reviewer on his device was the famous mathematician Mihail Ostrogradsky. In his review, he noticed, that the main idea was borrowed from Slonimski, but the construction resulted was incomparably simpler and more convenient in use. One of the major advantages of Kummer’s adding machine compared with Slonimski’s device was portability. Ostrogradsky noted that to a sheet of paper folded eight times, would be as thick as this device, but the length and the width will be much more. With smaller sizes, it would be inconvenient to deal with it.
In 1847 the device was presented as Kummer’s Selbstrechner in the newspaper St. Peterburgische Zeitung, Dienstag, 20 Mai (1. Juni) 1847.
One of the early devices, kept now in the collection of CNAM, Paris (see the lower image), is a large “desktop” version with dimensions 40 x 8,5 x 10,8 cm, and a weight of 95 g, but there are much smaller “pocket” devices with dimensions: 10 x 6 x 0.3 cm). There are also devices with multiplication and division facilities (writing pad). Materials used are cardboard, paper, and ferrous alloy. The device calculates in rubles and kopecks.
The slide adder of Kummer is probably the first slide adder equipped with a shepherd’s crook-carrying mechanism, which makes it particularly interesting.
The numbers are entered by means of stylus and laths, which can be moved along the troughs. At the side of the laths, the numbers from 0 to 9 are marked. The carrying is done by means of teeth. Each lath has a tooth, which can touch the similar tooth on the adjacent lath and move it in one position upwards or downwards if it is necessary.
The upper part of the device is for сложение (addition), lower part is for вычитание (subtraction). In the bottom left-hand corner, one can read деление (division) and in the bottom right-hand corner, умножение (multiplication). On the ivory lower part one can write auxiliary information needed in multiplication and division. A small round hole in a slide means that you have to draw the stylus to the right end and a large square hole that one has to make a tens carry by drawing the stylus in the direction of the crooked end.
To reset the device all laths must be slid downward to the stop position, thus in all result windows will appear zeroes.
The adding device of Kummer is the first device of this type, manufactured in quantity. Kummer received on 29 March 1847, a free 10 years patent (an extremely rare advantage) for his device (Привилегия на счетный снаряд, выданная учителю музыки Куммеру, 29 марта 1847 года, на 10 лет). The first seller (and probably manufacturer) of the adder was the famous watchmaker Иоганн Генрих Мозер (Johann Heinrich Moser (1805-1874) had a workshop and several watchmaker shops in Russia), later (since around 1870) the device was produced by the company Mechaniker und Optiker I. E. Milk (Мильк) in Moscow in significant quantity and later on was serially released (with various modifications) up to the 70s of the 20th century.
Kummer’s adding device was patented not only in Russia but also in France and USA. The French patent was filed in November 1847, by François Jacques Marc Auguste Billiard (1788-1858), an employee of the Ministry of the Interior (аt the time French patents could not be granted to foreigners, sо it can be assumed that Billiard was Kummer’s French agent). The USA patent 90275 of Kummer for Calculator (Improvement in computing-tablet) (see the lower image) was granted in 1869 to one Henry Kummer of New York, obviously the Americanized version of Heinrich Kummer of Dresden 🙂
Later on, adders like Kummer’s, for example, the Arithmographe of Troncet, became very popular and were manufactured in millions until the advent of the electronic pocket calculator in the 1970s.
There is a detailed description of Kummer’s Calculator (Счислитель Куммера) in the book Фон-Бооль, Приборы и машины для механическаго производства арифметических действий. Описание и оценка счетных приборов и машин, see the description of Kummer’s calculator.
Biography of Heinrich Kummer
The information for Heinrich Kummer in Russian sources is very scanty. It is mentioned only, that he was a teacher of music in St. Peterburg. Who was this mysterious person?
Carl Heinrich Gotthelf Kummer (known as Heinrich Kummer), was a German musician (bassoon player and pianist) and amateur engineer, born on 8 May 1809, in Dresden. He was the only son of the German bassoon virtuoso Gotthelf Heinrich August Kummer.
The father, Gotthelf Kummer was born on 23 January 1774, in Neustadt, near Dresden, as the third son of Johann Gottfried Kummer (1730-1812), the founder of the famous German musical family Kummers (Gotthelf’s elder brothers Carl Gottfried Salomon (1766-1850), and Friedrich August (1770-1849), also became famous musicians). Gotthelf was trained the music by his father and practiced chiefly on the bassoon, touring with great success in many European countries. Gotthelf Kummer died in Dresden on 28 January, 1857.
Following the steps of his father, Heinrich Kummer became a bassoon player and pianist but never managed to approach his father’s success. Instead of that, he demonstrated outstanding capabilities in the rather distant from the music field—mechanics.
As a boy, Heinrich learned to play several musical instruments, taught not only by his father, but also by several other famous German musicians, like Carl Krägen (1797-1879), Ignaz Moscheles (1794-1870), and Johann Hummel (1778-1837). Heinrich concerted with great success with his father all over Germany from being six years old, playing the piano and later bassoon. For example, in 1816, after a series of concerts, last in Munich, King Maximilian I Joseph of Bavaria awarded them with 300 golden ducats.
From 1827 to 1832 Heinrich was engaged as a bassoonist in the Dresden musical chapel, but in 1832, trying unsuccessfully to obtain a good permanent position as a musician, he left for two years for Poland, (a Russian province at this time), to work as a piano teacher in the family of the former administrator of the Lowicz principality, Obersten von Philippeus. In 1834 Heinrich went to St. Petersburg, Russia, where in 1837 he joined the Imperial Russian theater and opera orchestra as the first bassoonist.
While in St. Petersburg, Kummer designed not only his famous adding device, but also a bridge over Neva (in 1837), allowing traffic over the bridge while ships could simultaneously pass under it. The project was never realized, but the plan was preserved in Petersburg city archives. Studying for years birds and insects, Kummer constructed several automatic devices, powered by watch springs, which imitated the movement of fish in water and flying bird.
In 1847, after serving for ten years, Kummer received a full pension, and the next year he left Russia and settled in Schaffhausen, Switzerland. In 1851 he moved back to his home city, Dresden, where he continued to work as a music teacher.
Back in Switzerland and Germany, Heinrich Kummer was evidently more interested in shooting and rifles than in calculating devices. He made his rifles himself and even constructed a new System Kummer rifle (see the nearby image), which received prizes at several exhibitions in Frankfurt, Bremen, and Vienna. Moreover, he published a bestseller book about shooting (Der praktische Büchsenschütze, (The Practical Gunner), published in 1862, reprinted in 2013), and wrote many articles in the “German Rifle and Military Newspaper”, in which he dealt with the weapon and shooting-related questions. He also campaigned to introduce free-hand shooting in Saxony and helped set up two shooting ranges (Fischhaus near Dresden and Steiger near Pottschappel).
At the end of the 1860s, Kummer most likely visited the USA, as in 1869 in New York he received a patent for his calculating device (he used the English variant “Henry Kummer” of his name).
Heinrich Kummer died on 20 March 1880, in Dresden.