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KD5NJR > TECH 20.09.16 14:34l 100 Lines 5488 Bytes #999 (0) @ WW
BID : 1PQVI8MAT2XX
Read: GUEST
Subj: Re:Mechanical Calculation
Path: IW8PGT<CX2SA<N0KFQ<AE5ME
Sent: 160920/1201Z 44597@AE5ME.#NEOK.OK.USA.NOAM BPQ1.4.65
https://www.youtube.com/watch?v=hIinz4fKGpo
Video shows UCLA's Differential Analyzer, a mechanical computer, in 1948. "In December of 1977, the last working model of a mechanical differential analyzer in the world is donated by UCLA to the Smithsonian Institution for its pioneering computing display. The differential analyzer introduced much of Southern California industry to automatic computing, but became obsolete beginning in 1960 as it was replaced by computing machines with electronic circuits and vacuum tubes. From 1960 on, it was used mainly as a display piece, clanking away occasionally for student and public demonstrations."
This is a later mechanical calculator ;)
----- Message from kf5jrv@kb0wsa.mo.usa.na sent 2016/09/20 02:12 -----
Message ID: 2201_KF5JRV
Date: 2016/09/20 02:12
From: kf5jrv@kb0wsa.mo.usa.na
To: tech@ww
Source: AE5ME
Subject: Mechanical Calculation
R:160920/0212Z 44548@AE5ME.#NEOK.OK.USA.NOAM BPQ1.4.65
R:160919/1134Z 7859@N0KFQ.#SWMO.MO.USA.NA BPQ6.0.12
R:160919/1133Z 2201@KF5JRV.#NWAR.AR.USA.NA BPQ1.4.65
Mechanical calculation
In the 17th and 18th centuries, clockwork and precision engineering made it
possible to build devices that could add and subtract at the turn of a dial.
The designs of these adding machines differed in important ways. They both
inspired more complex work, like that of Charles Babbage and Konrad Zuse, and
made it possible to mass produce devices to aid in everyday arithmetic.
The Enlightenment development of gear-driven mechanisms captured the popular
imagination and inspired the design of amazing new machines. Devices known as
'automata', which often mimicked humans or animals, were invented by
clockmakers to entertain the ruling classes and so win their favour. Amongst
the most famous and advanced automata were a writing boy, various musicians,
and a digesting duck capable of eating kernels of grain before metabolizing
and defecating them.
A century earlier, John Napier had been restricted to paper or ivory to
build calculating tools. But by the 17th century, the growing popularity of
clocks and associated mechanisms meant that knowledge and working examples of
gears, levers, cams, pulleys, and cranks were in wide circulation, offering
exciting new possibilities for the automation of calculation.
Blaise Pascal
The world's first mechanical calculator is usually attributed to the
precocious French polymath, Blaise Pascal (1623-1662). Motivated by the
tedium of adding up long columns of tax figures for his father, the young
Pascal designed a gear and dial based machine for addition. Pascal's
first machine was completed in 1642, and he would go on to produce some 50
more during his unfortunately short life.
Pascal's device allowed the 'carrying' of numbers from one gear to another:
when, for example, 3 was added to 7, the mechanism caused a 1 to appear in the
appropriate place. However, the addition of large numbers required the
carrying across of numerous places, and necessitated a much greater force than
could be provided by hand.
Countryman Rene Grillet, a Royal watchmaker, and Englishman Samuel Morland
both invented machines incorporating Pascal's dials alongside Napier's rods,
but these had no mechanical carry mechanism. The problem of the carry was
deferred until engineering advances caught up.
Leibniz and the stepped drum
Wilhelm Gottfried von Leibniz (1646-1716), known for his creation of
calculus alongside Isaac Newton, began working on his own calculating
device in the 1670s. He was interested in automating not only addition and
subtraction but multiplication, division, and even taking square roots.
His device, known as the 'stepped reckoner', used large stepped drums that
meshed with secondary gears. One would slide the gear along an axle and it
would mesh with a different number of teeth depending on its position. Turning
the crank would cause all of the drums to rotate and add into counters, and
one could multiply by simply cranking the desired number of times.
This design was also used in the first mechanical cipher, which Leibniz built
a semi-operational model of and demonstrated before the Royal Society on a
trip to England in 1672. A later working model was recently uncovered after
being lost for 200 years.
Although Leibniz described the principles for his machine as early as the
1670s, it was a long time before they were applied to a practical design that
could be marketed. Charles Xavier Thomas de Colmar used Leibniz's design to
invent a machine known as an arithmometer. These bulky desktop machines, like
the later Burkhardt, were awkward to use but helped establish a market for
mechanical calculating devices.
In 1873, Willgodt Theophil Odhner, a Swedish émigré living in Russia, drew up
a practical, affordable, and efficient adaptation of Leibniz's machine that
was suitable for mass production. The German firm of Grimme, Natalis & Co.
bought out Odhner's German plant and secured manufacturing rights in 1892,
creating the 'Brunsviga' brand.
Its flagship machine can mechanically calculate sums using a complex system
of pinwheels coupled with geared carry mechanisms and a counter. Users would
input numbers and turn the handle clockwise for addition and multiplication or
anti-clockwise for subtraction and division. The owner of the Whipple Museum's
example was George Udny Yule, appointed as Cambridge's first University
Lecturer in Statistics in 1912.
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