On 9 May 1882, Walter C. Snelling (1859-1893) of New York, received US patent No. 257775 for an adding machine (column adder) with a capacity of up to 999 (see the lower patent drawing). The patent was assigned to Rastus Seneca Ransom (1839-1914), a notable lawyer and Surrogate of the City and County of New York.
The adding machine of Walter Snelling looks like it has a simple and reliable construction, but it never went into production and remained only on paper.
The operation of adding machine of Snelling is as follows:
Supposing the keys 5 and 6 to be depressed, when key 5 is struck the cog-wheel (marked with I) will rotate five teeth, and this, by means of the pawl S, will partially rotate the units-wheel R, and indicate 5 on its face. The rack H and cog I are now returned to their normal position by the springs M and N, and the machine is ready to count the next number. Now, when key 6 is struck the cog I will be rotated six teeth. This will move the units-wheel around, making one complete revolution for it and one tooth over. This one tooth will be indicated by figure 1 on the units-wheel, while the units-wheel in its revolution has caused the pin R2 to rotate the three-cornered wheel one-third, and has consequently indicated 1 on the tens-wheel. The face of the register will now indicate 11, the sum of 5 and 6. The operation is precisely the same, the counting continuing until the hundreds-wheel is caused to register. Only three wheels are shown on the drawing, but their number may be increased, and they may be operated in precisely the same manner to register any desired number.
Biography of Walter Snelling
Walter Comonfort Snelling, was born on 21 March 1859, in Chicago, Illinois, to William Walter Snelling (1829-1863), a sailor, and Susan Otheman Snelling (Macreading) (1836-1909), a teacher. Snellings are New England Protestants who arrived in America in 1649 one step ahead of Cromwell because they were royalists and Cromwell had a price on their heads. William Walter Snelling died at sea aboard the steamer “Salvor” en route from Washington DC to Boston when his son Walter Comonfort was only 4, on 3 Oct 1863.
Walter Comonfort Snelling married on 20 October 1879 in Washington, DC, to Alice West Hornor (1861-1919), from an old Quaker family, an American traveler, writer, newspaper correspondent, photographer, and suffragist, who was also one of the first women cyclists in America. They had three sons— Walter Otheman (1880–1965), Henry Hornor (1883-1944), and Charles Hornor (1887–1907). Their first son, Walter Otheman Snelling (see the nearby image), became a famous US chemist and inventor who contributed to the development of explosives and liquefied petroleum gas, and was known as The Father of Propane.
Walter Comonfort Snelling died only 34 years old (just like his father) on 1 July 1893, in West Chester, Pennsylvania. The next year Alice remarried John Oliver Moque, and they had a daughter, Voleta Alice Moque.