The slide rule was not immediately embraced by scientists, mathematicians, or
the public. It took until about 1850, when French artillery officer Victor Mayer
Amédée Mannheim (1831–1906) standardized the modern version of the slide rule,
adding the movable double-sided cursor that gives the slide rule its familiar appear-
ance. Slide rules were used for many decades as the major calculator for the sciences
and mathematics, and ranged in shapes from straight rules to rounded.When was a mechanical calculating devicefirst used for the American census?
When government officials estimated that the 1890 census would have to handle the
data from more than 62 million Americans, there was a slight panic. After all, the
existing system was slow and expensive, using tally marks in small squares on rolls of
paper, which were then added together by hand. One estimate determined that such
an endeavor would take about a decade to complete, which would be just in time to
start the process all over again for the 1900 census. In desperation, a competition was
set up to invent a device that could easily count the 1890 U.S. census.
Thus, in the 1880s, American inventor Herman Hollerith (1860–1929), who is
also known as the father of modern automatic computation, presented his competi-
tion-winning idea. He used Jacquard’s punched cards to represent the population data,
then read and collated the information with an automatic machine. With his Automat-
ic Tabulating Machine—an automatic electrical tabulating device—Hollerith would
put each individual’s data on a card. With a large number of clocklike counters, he
would then accumulate the results. From there, he would use switches so the opera-
tors could instruct the machine to examine each card based on a certain characteris-
tic, such as marital status, number of children, profession, and so on. It became the
first such machine to read, process, and store information.
The machine’s usefulness did not end there, though. Eventually, Hollerith’s device
became useful for a wide variety of statistical applications. Certain techniques used in
358 the Automatic Tabulating Machine were also significant, helping in the eventual
What is the Millionaire Calculator?
T
he Millionaire Calculator, invented in 1892 by Otto Steiger, saved many of
the problems associated with other devices’ multiplication. While earlier
machines required several turns of their calculating handle to multiply, the Mil-
lionaire multiplied a number by a single digit with only one turn of its handle.
Its mechanism included a series of brass rods varying in length; these rods exe-
cuted functions based on the same concept as Napier’s Bones (for more about
Napier’s Bones, see above). The calculator was a hit, and around 4,700 machines
were manufactured between 1899 and 1935.