Many of the nineteenth-century calculators
were simple instruments called “adders,” which had no internal
mechanism to compute mathematically, but relied on movable parts
to figure and record the result of such computations.
The first calculator marketed in Harper’s Weekly
was, in fact, an adder called the Fowler Adding Machine.
The small text-only advertisement
appeared in the
issue of September 26, 1863, the year it was patented by George B.
it was a slide adder, inspired by the abacus and comprised of
enumerated slide bars with holes or notches (instead of beads and
strings) fitted inside a flat rectangular case and moved with a
stylus. Six years
later, an item
in the “Home and Foreign Gossip”
column of the February 13, 1869 issue lauded the Fowler Adding
Machine’s simplicity of design and accuracy of results.
After joking that the Board of Education could now
eliminate math classes in the public schools, the columnist
remarked seriously that the “adding machine” would be of great
value to “book-keepers, accountants, and business-men
An adder with a very different look was
Webb’s Adding Machine, which was made of two enumerated rotating
disks (one larger, one smaller) encased as a unit.
The product’s advertisement
in the February 13,
1869 issue included endorsements from Vice President Schuyler
Colfax, evangelist Henry Ward Beecher, Mayor A. Oakey Hall of New
York City, and others. It
also got a promotional boost the next week in the publication’s
“Home and Foreign Gossip” column.
An illustration in an 1891 ad
revealed each disk
in the later model Webb Adder to be more distinct.
A third style of adder was a circular model manufactured by
William Furniss. His
product’s ad text in the January 8, 1876 issue promised
|Harper's Weekly References
26, 1863, p. 622, col. 3
ad, Fowler Adding Machine (1st ad)
13, 1869, p. 107, col. 4
news item, Fowler Adding Machine
13, 1869, p. 112, col. 4
illustrated ad, Webb’s Adding Machine
27, 1869, p. 135, col. 3
news item, Webb’s Adding Machine
6, 1891, p. S3, col. 1
illustrated ad, adder, Webb Adder
8, 1876, p. 35, col. 3
illustrated ad, “Rapid Addition” adder