George Grant

The American engineer and entrepreneur George Barnard Grant (1849-1917) is a notable figure in the world of the mechanical calculator. He was the creator of several all-purpose calculators, but also of a magnificent Difference Engine. As a whole, Grant devised four different calculating machines: three all-purpose calculators, and a sophisticated machine for computing tables.

While in Lawrence Scientific School of Harvard University, in 1869, George Grant got interested in calculating machines while he was computing a table for excavations and embankments, but he soon became discouraged with his initial efforts when he realized the subject was more difficult than he had anticipated. Thus between 1870 and 1872, he devised firstly a simple calculator and later continued with several more complex calculating machines. All his devices were well-designed and workable machines, and although none of them achieved market success, they fully deserve our attention.

The first calculating machine of George Grant

Grant filed his first two patent applications in 1872, and soon get patents for a simple calculating machine (US Patent №129335 from 16 July 1872, and №138245 from 29 April 1873). Let’s examine the machine, described in the second patent, which presents an improved version of the first one.

The numbers are entered through the openings of the lid (marked with P in the patent drawing), mounted on the sliders g and g’. The results are shown on the digital wheels (which are similar to teeth-strips), placed under the lid. Adding of the number is performed by means of the movable carriage C, which can be rotated by means of the handle H. On the lid are cut off slots (or openings in the first patent), in which are being pushed in the pin p. The slots (openings) are graduated with the digits from 1 to 9 and the number is entered by pushing in the pins in the appropriate openings, while the lowest row is for units, upper row is for tens, etc. In this way the entered number can be multiplied by 10 or divided to 10 (by moving upwards or downwards of the lid to one division). Besides the graduated digits are inscribed smaller digits (from 9 to 1), which are complementing to 9 of the bigger digits and are used during the subtraction and division. The digital wheels A, B, C, D and so on, are placed below the slots, and each wheel is divided by two (or three) groups of 10 teeth, each tooth is marked with a digit.

The machine has also a mechanism for zeroing the display of digital wheels.

The pins are acting as a stop for placed below digital wheels, which during the rotation of the handle (carrier) make a motion forward-backward and transfer the numbers from the input to the displaying mechanism.

In his patent from 1873, George Grant suggested three variants of the tens carry mechanism, depending on the capacity of the machine.

It seems the first machine of Grant remained only on paper and even the patent model (up to 1880, the Patent Office required inventors to submit a model with their patent application) didn’t survive to our time, but obviously, the inventor used it as a base during the creation of the much more successful…

The second calculating machine of George Grant

In 1876 Grant exhibited at the 1876 USA Centennial Exposition in Philadelphia, two calculating machines—a magnificent differential machine, and a smaller calculating device (also known as the Centennial Adding Machine), which has many improvements compared to his first calculating machine (patented in 1872) and was described in the third patent from 1887 (interestingly, the patent application for this machine was filed in 1878, but the patent was granted as late as 1887 (US Patent №368528), so obviously Grant had problems with this patent).

The official report of the United States Centennial Commission mentioned:
The most important exhibits of this class [Mechanical Calculation] were the two calculating machines of Mr. George B. Grant, of Cambridge, Massachusetts, the larger one of which is arranged to combine and print functions involving 100 elements. The combination of the several parts is extremely simple; the number of elements can be indefinitely increased, and the machine acts with the greatest certainty. The smaller machine, or arithmometer, is an adding-machine, which successfully rivals the well-known one of Colmar. The adding-machine of Petersson, of Norway, also deserves special mention here.

The above-mentioned arithmometer was a device, made from some 400 parts, 30 cm long and 15 cm high. Several copies were built and are to be found in the Smithsonian and private collections, but the machine was never placed in commercial production. Grant was able to get this device to operate rapidly (…a poorly made apparatus has been worked at the rate of 10,000 operations per minute with perfect accuracy) and may well have used this as part of his experiments to produce other calculating machines.

This machine was reported to be intended for use in counting houses, insurance offices, etc., and was described as a smaller instrument for common operations in multiplication, division, etc. It is a foot in length by half as much in height and width, weighs twenty pounds, and contains less than 400 pieces, less than 75 of which are working parts. It takes numbers up to nine decimal places.

In 1881, Grant exhibited this machine in his home state at Fourteenth Exhibition of the Massachusetts Charitable Mechanic Association, Boston, 1881, and won a gold medal. The report of the exhibition stated: This calculating machine has now stood the test of practical use, several of the machines having been employed during the past three years. It is admirably adapted for an extensive range of computations in multiplication and division, and surpasses all other instruments now used for such computations in respect to simplicity, strength, compactness, durability, cheapness, rapidity and accuracy of operation.

There are several different examples of the Centennial Model in the collection of the National Museum of American History (see one of them in the photo below).

One of the models in the museum (overall measurement: 19.5 cm x 34.3 cm x 14.4 cm) has a rectangular wooden base, cut out to allow for the motion of a set of wheels that rotates on a shaft near the bottom. This shaft is linked to a larger upper cylinder by gears so that the wheels and the cylinder turn simultaneously when a handle at the right end of the upper cylinder is rotated. The frame for the instrument consists of hollow discs at opposite ends of the base, which are connected to the two shafts already mentioned, and a third shaft that carries a set of 20 spring claws that link to the gears of the wheels.

The frame is made up of two plates at either end of the base connected by metal shafts. The mechanism has a large upper cylinder and a small lower cylinder linked by gears of equal size. Part of the upper cylinder has a metal collar that can be set at any of 18 positions on the cylinder with a locking pin. This collar supports 18 movable rings. Each ring has an adding pin and a stud on it which may be set at any of ten positions, labeled by the digits from 0 to 9. The lower cylinder has 20 (or 10 in some examples) recording wheels on it, each provided with 30 teeth. The digits from 0 to 9 are stamped three times around each wheel. The spring claws fit the gears of the recording wheels. If a claw is pushed down, it engages the gear of the recording wheel, causing it to rotate. Studs on the wheel lead to carrying by engaging the next claw over.

Paper loops numbered from 0 to 9 three times run around each wheel. On a bar between the cylinders is a row of ten spring claws, one for each recording wheel. If a claw is pushed down, it engages the gear of the recording wheel, causing it to rotate. Studs on the wheel lead to carrying by engaging the next claw over.

This model has no mechanism for displaying the multiplier or multiplicand. A flat disk at the end of a lever on the left side serves as a brake on the operating wheels, indicating when the operating crank has been turned through one revolution.

The judges at the Centennial Exhibition gave Grant an award for his invention, and described his machine as “superior to all other instruments of its class yet produced.” It was lauded by actuaries and distinguished professors but never gained large sales. This version of the machine was sold for $100.

In 1898, Encyclopaedia Britannica reported that there were numerous crank-operated calculating machines for multiplication and division, including machines made by Thomas, Tate, Odhner, Baldwin, and Grant. “Grant’s machine consisted of a cylinder bearing a set of rings on which were the numerals. These he terms adding-rings. A similar set of rings is placed on a shaft below, and these he terms registering wheels. In order to multiply, the adding-rings are set to read the multiplicand, and the registering-wheels the multiplier. If the multiplicand was 387432, the crank would be turned three times and a slide shifted, then eight times and a slide shifted, and so on. At the conclusion of the turning the answer could be read on the recording-wheels.”

The third calculating machine of George Grant

At the beginning of the 1890s Grant designed a new calculating machine (patented in 1898, US Patent №605288), added a printing device, and began serial production of his calculator (advertised as “ciphering hand-organ”) with some success (about 125 machines were sold) until the end of the 19^th century. This calculating machine (called Grant’s Grasshopper Model because of its appearance) was exhibited at the Columbian Exposition held in Chicago in 1893 and was described in the journal Manufacturer and Builder, vol. 26, issue 9 (Sep. 1894) (see the figure below). Later on, Grant designed an experimental model, designed to incorporate subtraction and division as well as addition and multiplication.

The machine (overall measurements: 20.7 cm x 24 cm x 27.5 cm; weight: 4.5 kg) has an open iron frame painted black, with steel and brass parts and paper labels. Five sliding pins at the front of the machine are used to set numbers on racks beneath. Next to each pin is a thin strip of paper with the digits from 0 to 9 printed on it. The digits increase as one goes toward the back of the machine. Each strip also has complementary digits in smaller type, for use in subtraction and division. Moving back a pin drives back a toothed rack.

Behind the racks is a movable carriage with 11 gears on it. A paper strip with digits on it is next to each gear. Turning a crank at the front right of the machine moves the racks back to engage the gears, turning each one of them in proportion to the number set. When the adding frame reaches the end of its backward movement, a cam set on the crankshaft at the front raises all the register gears a little so that the gears are disengaged from the racks and not moved in the return motion. One tooth on each gear extends so that when the gear has made a complete rotation, it engages one of the carry teeth arranged on a spiral shaft above the carriage. As the adding racks return to position, the shaft revolves and the carry tooth pushes the next gear up by one, resulting in a carry. The result appears o the paper strips between the gears on the carriage.

Fourth calculating machine (difference engine) of George Grant

Grant’s interest in construction mechanical calculators was aroused while at the Lawrence Scientific School he was computing a table for excavations and embankments, but he became discouraged with his initial efforts when he realized the subject was more difficult than he had anticipated. In 1870, however, he heard of the Babbage difference engine and proceeded to design one himself. Upon meeting with skepticism concerning the workability of his design, he again laid it aside.

Grant was aroused to resume work on the project when Professor Wolcott Gibbs inquired about his progress and encouraged him to pursue it further. Grant was in the right place: His major supporter, Wolcott Gibbs (1822-1908), since 1863 Rumford Professor of Chemistry at Harvard, was a member of that circle of scientists whose older leaders had supported Gould and his endeavors at Albany. Henry Lawrence Eustis (1819-1885), a Professor of engineering, who became Dean of the Lawrence School in 1871, approved and helped the project. Another supporter was Joseph Winlock, director of the Harvard College Observatory, who when was head of the Nautical Almanac had approved the work done on the Scheutz machine for that office. John M. Batchelder, who had operated the Scheutz machine at Albany as one of Gould’s Coast Survey assistants, was in Cambridge, ready to advise Grant.

Grant described the design represented in this model in the August 1871 issue of the magazine American Journal of Science. The publication, entitled “On a New Difference Engine” (see the article of Grant), included references to several accounts of the Babbage and Scheutz difference engines, such as Lardner’s detailed article from 1834 in Edinburgh Review, the 1854 British patent specifications of the Scheutz machine, and some of Babbage’s own writings dealing with both machines. The version of the machine described in this 1871 article had numerous features in common with the Scheutz machine. Thus, it too was designed to print by stamping the result on a sheet suitable for stereotyping. Grant did not describe the printing mechanism, beyond observing that it contains nothing new of importance. Again there was a set of number wheels, and as in Wiberg’s machine, their arrangement differed from that in the Scheutz machine by being purely linear. For a maximum capacity of n digits per number, there were n sets of these wheels, each using m wheels if the m^st difference was constant. All these wheels were arranged along a common axis. Again, odd orders of differences were added simultaneously in one operation, even ones in the next.

Following this publication, Grant continued to occupy himself with the problem of mechanical calculation. Aside from reading widely in the existing literature, particularly the patent literature. Upon his graduation, his scientific benefactors supported the further development of the difference engine. In 1874 the Boston Thursday Club raised a subscription for the construction of a large-scale model, which was supplemented by substantial support from Fairman Rogers of Philadelphia. Rogers not only supported the construction of the machine, but saw to it that Grant exhibited the machine at the 1876 Centennial International Exhibition in Philadelphia (see the lower figure), along with a small general-purpose calculator.

The official report of United States Centennial Commission mentioned:
The most important exhibits of this class [Mechanical Calculation] were the two calculating machines of Mr. George B. Grant, of Cambridge, Massachusetts, the larger one of which is arranged to combine and print functions involving 100 elements. The combination of the several parts is extremely simple; the number of elements can be indefinitely increased, and the machine acts with the greatest certainty…

The difference machine of Grant was approximately 2.5 meters long and 1.5 meters high, and weight about 900 kg. It consists of up to 15000 pieces and is worth about 10000 $. It could be manually operated or connected to a power source. It was said to calculate 10 to 12 terms per minute when hand-cranked and to compute more than double that amount when power-driven; small sections of it had been tested at even higher speeds. The inventor emphasized the flexibility of the machine, which allowed any number of wheels of the k^th order of differences to be added to any wheel of the k-f 1^st order.

An important distinction between this difference machine and the model described in 1871 lay in the arrangement of the number wheels. It was again linear. But in the 1871 model, the wheels had been grouped by place figures, all the lowest decimal values being grouped together, then the next highest decimal value, etc. Within each such group appeared first the appropriate digit of the tabular value, then the corresponding one of the first order of differences, then that of the second order, and so on. Now the numbers were regrouped: all digits of the tabular value came first, then those of the first difference, then the second, etc. As a result, the carry mechanism, which was closely related to one covered by Grant’s general-purpose calculator patents, was simplified. The printing apparatus connected ten of the tabular function wheels with corresponding die-plates holding wax moulds for subsequent electrotyping.

Despite some publicity and favorable notices at the time of the exhibition (the insurance company Provident Mutual Life Insurance Co. even ordered a machine made to Grant’s design for purpose of calculating life insurance tables), the difference machine soon faded into relative obscurity. After Grant’s death in 1917, his difference engine, sent back to Philadelphia in the 1890s, had assumed the status of an antiquated curiosity.

Biography of George Grant

George Barnard Grant was born in Farmingdale (at that time part of Gardiner), Maine, on 21 December 1849, to Peter Grant (1806-1855), a farmer and shipbuilder, and his second wife Vesta Jane (Capen) Grant (1826-1915). Both his parents were descended from families that originally came from Britain to New England in the middle of the 17^th century (Grant family were descendants of James Grant (1605-1683) of Auchterblair, captured at the Battle of Worcester (1651) and deported to America together with his wife Agnes and son Peter).

Peter and Vesta Jane Grant married in 1844 and had three children: Izanna (1845–1924), William (1847–1847), and George Barnard (1849–1917), but Peter had four children from his first marriage to Margaret (Swan) Grant (1812–1843): Francis Swan (1836–1843), Peter (1838–1894), Catherine (1839–1850), and Margaret (1842–1865).

Peter Grant, the father of George Barnard, was the son of Peter Grant (1770–1836), and Nancy Barker Grant (1772–1853). Peter Grant Sr. was a native of Berwick, Maine, who moved to Gardiner in 1790. Finding financial success in land speculation and the merchant trade, Grant purchased 200 acres between Gardiner and Hallowell in 1800, and built a house there. His first house was destroyed by fire, and he had a new house built in 1830 as its replacement. Now the Peter Grant House (see the nearby photo) is a historic house at 10 Grant Street in Farmingdale. It is one Maine’s oldest surviving examples of Greek Revival architecture, with a temple front overlooking the Kennebec River. It was listed on the National Register of Historic Places in 1976.

George Grant lost his father in May 1855 when he was only five years old, and in 1861 his mother Vesta remarried Edwin Allen Bailey, a farmer from Vermont. George Grant attended Bridgton Academy in Maine, then studied for three terms at the Chandler Scientific School of Dartmouth College, and entered in 1869 the Lawrence Scientific School at Harvard, where he obtained his bachelor’s degree in engineering in 1873.

While in Lawrence Scientific School, in 1869, Grant got interested in calculating machines, and in Aug. 1871 he published a paper On a new difference engine in the American Journal of Science. Between 1872 and 1898, George Grant patented and manufactured in his company Grant Calculating Machine Company of Lexington, Massachusetts, several models of calculating machines. Grant continued to take an interest in this area and in his later years carried out experimental work on their development.

Grant became best known, however, not for his remarkable mechanical calculators, but for establishing a business that was a derivative of his experimentation with calculators. Just as Babbage’s needs had led to advances in precision tool and parts manufacture in England, and Donkin’s requirements for the second Scheutz machine caused him to develop new production techniques, so Grant discovered that, to obtain gears of the accuracy required for his calculators, he had to cut his own gears.

Soon after his graduation from Harvard in 1873, Grant established a gear-cutting machine shop in Charlestown, Massachusetts, and developed a successful machine for cutting gears using a device called a hob. When this business expanded, he moved the workshop to Boston, expanded it, and named it the Grant Gear Works Inc. From this extremely successful establishment evolved the Philadelphia Gear Works and the Cleveland Gear Works Inc. George Grant even wrote several very successful articles and books on the subject, for example A treatise on gear wheels; A handbook on the teeth of gears, their curves, properties and practical construction, etc. George Barnard Grant is considered one of the founders of gear-cutting industry in USA, and obtained several patents in this area.

After graduation from Harvard, Grant lived in Boston and Maplewood, Mass. He moved to Lexington, Massachusetts in 1887, and then to Pasadena, California, around 1900. In California Grant paid attention to his hobby—botany, especially the collection of preserved southern California plants (there are even several flowers called after him—Trifolium grantianum, Ribes grantii, Saltugilia splendens), creating a big private herbarium, which is now part of the Stanford University herbarium.

George Barnard Grant died on 16 August 1917, in Pasadena, California, having never married.