Necessity… the mother of invention.
In June and November 1885, Lawrence Wilson Swem (1856-1917), a jeweler of West Liberty, Muscatine, Iowa, filled two patent applications for a simple keyboard-operated adding machine, somewhat similar to the earlier adder of Marshall Cram from 1877 and very similar to the later adding machine Centigrpah of Arthur Shattuck from 1886 and 1891. The first patent (US patent No. 327970) was granted on 6 Oct 1885, while the second patent (US patent No. 343506) was granted in June 1886. The witness of the first patent was Jonathan (Jout) Maxson (1833-1925), a leading man in the local community, a clerk, merchant, and Postmaster at West Liberty, so we can easily guess one reason this machine was created.
Like other machines of this kind (so-called single-column adders), the device of Swem was intended to add a single digit at a time, i.e. the unit column is entered first, then the tens, the hundreds, the thousands, and so on, certainly a rather cumbersome task (as every partial sum had to be recorded on paper and the sum eventually performed), which greatly limits the usefulness of such devices.
Let’s examine the internal mechanism and operation of the adding machine of Swem, using the second patent drawing (see the lower image).
The numbers, entered by the keyboard, are transferred to the ratchet-wheel (B) by means of the rock-shaft (A). The wheel (B) is turning is turning freely or loosely thereon, and is provided with a specific number of teeth, ordinarily one hundred. This wheel can be rotated only in one direction, which is secured by a radial arm (C), a pawl-arm (D), retaining-pawl (F), and a spring (B’).
Secured to the ratchet-wheel (B), so as to turn with it, is a disk (G), having a series of numbers (from 1 to 99) on its periphery. The number entered on the disk (G) can be ascertained by means of a suitable indicator (G’).
The carry mechanism is implemented by means of a cam (H), mounted on one side of the disk (G), on which rests one end of the arm (I), the other being pivotally supported on a post (K), erected on the base (E). The post (K) has on top an extension (L), which supports a ratchet-wheel (M), with a specific number of teeth, say 14, and a plate (N), with an orifice (O), through which may successively be seen numbers on the said ratchet-wheel (M), corresponding in position to the teeth thereon. When the disk (G) has revolved once, the cam (H) will raise the arm (I) till it has reached the apex of the said cam and will carry the pawl (R) from one tooth of the wheel (M) to another.
Thus it is evident that if there are 99 numbers on the disk (G) and 14 on the wheel (M), any number from 1 to 1500 may be indicated, and the addition of amounts till the said sum is reached easily and rapidly accomplished without mental labor.
Biography of Lawrence Swem
Lawrence Wilson Swem was born in West Liberty, a small town in Muscatine County, Iowa, on 24 April 1856, to Ezra Brown Swem (14 Apr 1815-17 Nov 1871) and Phoebe (Phebe) H. Swem (nee Gregg) (11 Jan 1819-17 Jan 1887), a dressmaker. Ezra married Phoebe on 3 December 1837, in Wayne, Indiana, and they had nine children, but it seems only seven of them survived to adulthood: two girls—Amanda Jane (1842-1921), Mary (1848-1869), and five boys—Edward Lawrence (23 Oct 1838-4 May 1918), James Madson (30 Mar 1845-10 May 1909), Lawrence Wilson (24 Apr 1856-28 Sep 1917), Ross Elden (1858-1921), and William Carroll (7 Apr 1861-1 Apr 1931).
At the age of 12, Lawrence went to Belle Plain, Iowa, with his parents. He returned to West Liberty, however, and for several years conducted a jewelry store there. He also served the town as mayor for several years. In 1912 Swem retired from the jewelry business, to devote all his time to manufacture of the ring moulds. In his busy life, he also found time for the study of law and was admitted to the bar, though he did not practice the profession.
Besides the above-mentioned patents for adding machines, Lawrence Swem was a holder of several more US and Canadian patents for various devices like—lamp extinguisher (patent US201570), hydraulic air pump (US556220), gas-making apparatus (US595979), mold for castings of precious metal (US981033), ring expanding press (US1154893), hydrocarbon burner (US1216248), and gaz machine (CA052056). His burner was implemented on practically all kerosene lamps. His Swem Ring Mould for the casting of perfect gold rings has been in great demand since it was placed on the market. In its manufacture, Swem was associated with Edward Livingston Webb (1866-1963), a West Liberty businessman.
Lawrence Swem married on 28 June 1877, to Elva Ora Swem (nee McFadden) (18 Jan 1859-14 Dec 1922). They had three children, two boys—Roy J. Swem ( 9 Aug 1878-2 Oct 1934), and Azel Clark (22 Apr 1891-4 Apr 1958), and a girl—Gay Lucetta (18 May 1881-23 Sep 1959).
In 1914 Swem and his wife and younger son moved to Iowa Falls, Hardin, Iowa, where their daughter Gay Lucetta (Mrs. Frank Wilbur) married and lived. Lawrence Wilson Swem, a man of remarkable mind, died of diabetes on 28 September 1917, in Iowa Falls, at the age of 61, and was buried in Oak Ridge Cemetery, West Liberty, Muscatine, Iowa.
Note: Biographical information for Lawrence Wilson Swem was kindly provided by Lynn McCleary, the President of Muscatine Co. Genealogical Society.