The Portable Adding Machine is a simple and compact adding listing machine from the mid-1920s. It has a full keyboard with 7 columns. If you enter a number on the keyboard and pull the large lever, the number is printed and gets added to the internal register, and the keyboard input is cleared automatically. There are 4 further controls. The switch lever at the far left has two functions - when pulled forward (marked Error) it clears the keyboard, and when pushed back (marked Repeat) it will not clear the keyboard automatically after every addition to allow repeated addition of the same number. At the back right is the Total button, which can be held down with the thumb as you begin to pull the lever, and that will print the current subtotal. This button is disabled if the last addition involved carries, in which case an extra pull of the lever is needed before the total can be printed. At the front right is the Non-Print button which can be locked down to disable the printing during the next addition. The button at the middle right (marked C or Clear) can be locked in the down position, and serves two functions - instead of an addition it will just print the number without adding it, and instead of a subtotal it will print the total, i.e. also clear the register. The button automatically unlocks after the lever is pulled.
I have not found any serial number on the machine. It was made in 1924 or 1925, since it is not yet named the Corona.
The machine is very cleverly designed to be as simple as possible, which allowed it to be relatively cheap ($65 in 1924, which is equivalent to about $1150 today). The printing is done by moving the paper forward against the type. The ink ribbon reels are mounted together on the left side of the case, with a simple and compact advancing mechanism that is triggered by the movement of the paper. Another simplification is that there is no mechanism to deal with zeroes - you need to enter any zeroes in a number or else they will not be printed, and when totals are printed they will have leading zeroes. Using the Non-Add/Clear button causes a little dash to be printed after the number, so this simple combined mechanism allows you to distinguish subtotals from totals, and additions from non-additions.
This adding machine was in pretty good condition when I found it at a large antiques market. I just had to find replacements for two springs that were missing from the ink ribbon mechanism, give it a clean and replace the ribbon and add paper.
The Portable was designed by Glenn J. Barrett. At first he designed typewriters, working for Fox Typewriter Company in Grand Rapids, and then in 1904 he set up the Barrett Typewriter Company to produce his own typewriter. He then left typewriters behind and designed an adding machine, and in 1910 set up the Barrett Adding Machine Company to produce them. He left that company about 5 or 6 years later to become a consultant to other adding machine companies such as Burroughs. In about 1923 he designed the Portable adding machine and set up the Portable Adding Machine Company to market it. That company contracted out the manufacturing to the Corona Typewriter Company, a reputable typewriter manufacturer.
The Corona Typewriter Company began in 1906 as the Rose Typewriter Company, and made the first successful portable typewriter. in 1909 they were bought by the L.C. Smith & Bros. Typewriter Company and renamed the Standard Typewriter Company. The model Corona portable typewriter became very successful, and led to yet another name change in 1914 to the Corona Typewriter Company. Finally, in 1926 Corona and the parent company L.C. Smith & Bros. were reorganised to become L.C. Smith & Corona Typewriters Inc.
The Portable Adding Machine Company's ties to Corona became ever closer. In August 1925 the Portable adding machine was renamed the Corona adding machine. The company moved to Syracuse NY in 1928, to where Smith & Corona were based, and officially became a division of the latter. From 1931 all sales of the Corona adding machine were done through the Smith-Corona dealerships, which essentially meant the end for the Portable Adding Machine Company. Glenn J. Barrett officially retired in 1934, but still continued to develop his machine, even resulting in a further patent. In 1958 Smith-Corona bought Marchant and became Smith-Corona-Marchant (SCM). While they did move into electronic desk calculators, they could not compete against electronic pocket calculators, so stopped making calculators in the early 1970s.
The Portable/Corona adding machine was continuously improved and developed, so versions of the machine were in production from late 1923 until the 1960s. It is difficult to find out information about all the variant models. In the advertisements the models are often given simpler names/numbers that do not match the list of model designations found in official records. In the table below I have gathered observations from ads and articles.
| Date | Description |
|---|---|
| 1923-08 | Portable Adding Machine announced. It cost $65, had 7×7 capacity, a single (Sub)Total button, full keyboard with small keys and including zeros, black cast metal case. It took about a year till mass production was underway. |
| 1925-08 | Renamed to Corona Adding Machine. Now has separate Total and Subtotal buttons, larger key tops and red buttons instead of zeroes. |
| 1926-07 | Corona Cash Register announced. This combines the Corona adding machine with an Indiana cash drawer and Hanna register. The left key column of the adding machine is used for marking the type of transaction. |
| 1927-09 | Corona Accounting Cashier is the updated version of the cash register. It has a new case that encloses the printing mechanism. |
| 1928-05 | Corona 10 produced. It has 9×10 capacity, larger key tops with complementary digits, a subtract button in place of the non-print button, and the closed case of the cash register. The standard adding machine is unchanged and now called the Corona 7. |
| 1928-12 | Corona 9 produced. It like the Corona 7 but with 9×10 capacity. No Non-Print button, but Non-Print lever on the printing mechanism. |
| 1929-07 | Corona 7 redesigned. Larger keytops, Non-Print lever instead of button. |
| 1940-07 | Model 6K has 5×6 capacity. Probably in production since about 1933. |
| 1946-09 | Models 8M to replace the 8K. Closed grey case with window, with paper ejector button. |
| 1949-08 | Case restyled in grey-brown, with a larger window, and green keys ("colorspeed" keyboard). |
| 1956-08 | Case restyled in light grey, without a window, larger totals buttons, white/brown keys. |
| 1960-03 | Case restyled in white grey or beige, handle and keys of the same colour set against a black keyboard plate. Subtracted numbers printed in red (on models with subtraction). |
Fortune, August 1944: A Dream of Reconversion
| Patent | Filing date | Publish date | Name | Description |
|---|---|---|---|---|
| US 1,681,567 | 07-05-1923 | 21-08-1928 | Glenn J. Barrett; Portable Adding Machine Company | Accumulator-control means |
| US 1,734,069 | 31-08-1927 | 05-11-1929 | Glenn J. Barrett; Portable Adding Machine Company | Listing mechanism |
| US 1,743,261 | 24-12-1928 | 14-01-1930 | Glenn J. Barrett; Portable Adding Machine Company | Locking device for case |
| US 1,784,862 | 14-08-1925 | 16-12-1930 | Glenn J. Barrett; Portable Adding Machine Company | Keyboard module |
| US 1,788,376 | 14-08-1925 | 13-01-1931 | Glenn J. Barrett; Portable Adding Machine Company | Ribbon feeding mechanism |
| US 1,804,736 | 24-12-1928 | 12-05-1931 | Glenn J. Barrett; Portable Adding Machine Company | Paper feeding mechanism |
| US 1,811,840 | 14-08-1925 | 30-06-1931 | Glenn J. Barrett; Portable Adding Machine Company | Adding listing machine |
| US 1,812,129 | 07-10-1927 | 30-06-1931 | Glenn J. Barrett; Portable Adding Machine Company | Calculating mechanism |
| US 1,812,130 | 14-08-1925 | 30-06-1931 | Glenn J. Barrett; Portable Adding Machine Company | Adding listing machine |
| US 1,812,161 | 15-07-1926 | 30-06-1931 | Clarence Orin Mapel; Portable Adding Machine Company | Printing mechanism |
| US 1,829,727 | 22-10-1927 | 03-11-1931 | Glenn J. Barrett; Portable Adding Machine Company | Paper rewind |
| US 1,906,304 | 23-10-1931 | 02-05-1933 | Glenn J. Barrett; Portable Adding Machine Company | Printing mechanism |
| US 1,925,089 | 08-09-1931 | 05-09-1933 | Glenn J. Barrett; Portable Adding Machine Company | Totalling device |
| US 1,935,609 | 17-06-1931 | 21-11-1933 | Glenn J. Barrett; Portable Adding Machine Company | Total key unlocking means |
| US 1,947,512 | 08-09-1931 | 20-02-1934 | Glenn J. Barrett; Portable Adding Machine Company | Automatic signal |
| US 1,949,445 | 11-04-1932 | 06-03-1934 | Glenn J. Barrett; Portable Adding Machine Company | Non-add key latching mechanism |
| US 1,949,446 | 06-10-1932 | 06-03-1934 | Glenn J. Barrett; Charles H. Bradt; Portable Adding Machine Company | Adding listing machine |
| US 1,949,706 | 25-04-1932 | 06-03-1934 | Glenn J. Barrett; Portable Adding Machine Company | Printed clear indication |
| US 1,951,592 | 27-04-1931 | 20-03-1934 | Glenn J. Barrett; Portable Adding Machine Company | Zero suppression |
| US 2,199,253 | 06-05-1938 | 30-04-1940 | Glenn J. Barrett; L.C. Smith &Corona Typewriters Inc. | Carry mechanism |
| US 2,218,108 | 16-01-1939 | 15-10-1940 | Edwin L. Harmon; L.C. Smith &Corona Typewriters Inc. | Paper feed mechanism |
| US 2,281,742 | 02-11-1939 | 05-05-1942 | Charles H. Bradt; L.C. Smith &Corona Typewriters Inc. | Key column for item type |
| US 2,539,906 | 22-04-1947 | 30-01-1951 | William J. Higgins; L.C. Smith &Corona Typewriters Inc. | Full stroke mechanism |
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