Types Abacus: Abacus Napier - Abacus Card
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Types Abaci
Abacus Napier,
Abacus Card
Image Source
Wikimedia Commons
License: CC 3.0, 2.5. ...
Attribution: Luis Garcia
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Napier or Card Abacus Inventor
John Napier, built several types of abacus, including one of the most important is: the Abacus card.
Napier or Card Abacus Structure
The apparatus consists of a wooden box inlaid with bone. The top section contains "bones" and at the bottom the card abacus. This card abacus consists of 300 cards stored in 30 boxes. One hundred of these cards are covered with numbers (known as the "number cards"). The remaining two hundred cards contain small triangular holes, which, when placed on top of the number cards allow the user to view only certain numbers. By positioning these card's Abacus can, multiplication can be done to limit number of 100 digits in length, on the other number 200 digits long.
Also, the doors of the box containing the first powers of numbers, the coefficients of the terms of the first powers of the binomial and numerical data on regular polyhedra.
It is not known who was the author of this work, or if it is of Spanish origin and came from a foreigner, but probably originally belonged to the Spanish Academy of Mathematics ( which was created by Philip II ) or was a gift from the Prince of Wales then. The only thing that is certain is preserved in the Palace, from where he moved to the National Library and later the National Archaeological Museum, where it still remains.
In 1876, the Spanish government sent the device to the exhibition of scientific instruments in Kensington, where he received much attention consulted several companies, including Spanish representation on the origin and use of the apparatus.
