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In-Depth Information
37 6
64 24
61 6
125 30
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Now the differences are all the same. You can retrieve the function values by a
pattern of additionsȌyou need to know the values at the fringe of the pattern and
the constant difference. This method was very attractive, because mechanical
addition machines had been known f
or some time. They consisted of cog wheels,
with 10 cogs per wheel, to represen
t digits, and mechanisms to handle the carry
from one digit to the next. Mechanical multiplication machines, on the other hand,
were fragile and unreliable. Babbage built a successful prototype of the Difference
Engine (see the Babbage's Difference Engine figure) and, with his own money and
government grants, proceeded to build the table-printing machine. However,
because of funding problems and the difficulty of building the machine to the
required precision, it was never completed.
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Babbage's Difference Engine
