Origin of Modern Calculating Machines: A Chronicle of the Evolution of the Principles that Form the Generic Make Up of the Modern Calculating Machine

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Western society of engineers, 1921 - Calculating-machines - 196 pages
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Contents

I
5
II
17
III
50
IV
79
V
111
VI
144
VII
149
VIII
163
IX
174
X
190
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Page 55 - I have always called it the macaroni box model. For keys I procured some meat skewers from the butcher around the corner and some staples from a hardware store for the key guides and an assortment of elastic bands to be used for springs. When Thanksgiving day came I got up early and went to work with a few tools, principally a jackknife. I soon discovered that there were some parts which would require better tools than I had at hand...
Page 179 - The use of the slips for the purpose of multiplication is now evident ; thus, to multiply 2085 by 736 we take out in this manner the multiples corresponding to 6, 3, 7 and set down the digits as they are obtained, from right to left, shifting them back one place and adding up the columns as in ordinary multiplication, viz., the figures as written down are 12510 6255 14595 1534560 Napier's rods or bones consist of ten oblong pieces of wood or other material with square ends.
Page 179 - may be easily explained by imagining ten rectangular slips of cardboard, each divided into nine squares. In the top squares of the slips the ten digits are written, and each slip contains in its nine squares the first nine multiples of the digit which appears in the top square. With the exception of the top square, every square is divided into parts by a diagonal, the units being written on one side and the tens on the other, so that when a multiple consists of two figures they are separated by...
Page 55 - I went to the grocer's and selected a box which seemed to be about the right size for the casing. It was a macaroni box, so I have always called it the macaroni box model. For keys, I procured some meat skewers from the butcher around the corner and some staples from a hardware store for the key guides, and an assortment of elastic bands to be used for springs.
Page 179 - ... 3, 8, 6, the seventh of 1, 4, 8, 5, the eighth of 2, 3, 7, 6, the ninth of 2, 4, 7, 5, and the tenth of 3, 4, 6, 5. Each rod, therefore, contains on two of its faces multiples of digits which are complementary to those on the other two faces ; and the multiples of a digit and its complement are reversed in position.
Page 56 - I had expected to construct in a day was a long way to be complete or in working order. I finally had some of the parts made out of metal and finished the model soon after New Year's Day 1885.
Page 179 - ... 1, 9, 8, the second of o, 2, 9, 7, the third of o, 3, 9, 6, the fourth of o, 4, 9, 5, the fifth of 1, 2, 8, 7, the sixth of 1, 3, 8, 6, the seventh of 1, 4, 8, 5, the eighth of 2, 3, 7, 6, the ninth of 2, 4, 7, 5, and the tenth of 3, 4, 6, 5. Each rod, therefore, contains...
Page 179 - Napier's rods or bones consist of ten oblong pieces of wood or other material with square ends. Each of the four faces of each rod contains multiples of one of the nine digits, and is similar to one of the...
Page 179 - ... 8, 6, the seventh of I, 4, 8, 5, the eighth of 2, 3, 7, 6, the ninth of 2, 4, 7, 5, and the tenth of 3, 4, 6, 5. Each rod therefore contains on two of its faces multiples of digits which are complementary to those on the other two faces; and the multiples of a digit and of its complement are reversed in position. The arrangement of the numbers on the rods will be evident from fig.
Page 55 - I knew that many accountants could mentally add four columns of figures at a time," Dorr Felt says, "so I decided that I must beat that in designing my machine.

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