Page:The Construction of the Wonderful Canon of Logarithms.djvu/72

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''the various improvements of Logarithms, the more important is that which adopts a cypher as the Logarithm of unity, and 10,000,000,000 as the Logarithm of either one tenth of unity or ten times unity. Then, these being once fixed, the Logarithms of all other numbers necessarily follow. But the methods of finding them are various, of which the first ws as follows:—''

''Divide the given Logarithm of a tenth, or of ten, namely 10,000,000,000, by 5 ten times successively, and thereby the following numbers it will be produced, 200000000 400000000, 400000000, 800000000, 1600000000, 3200000000, 640000, 128000, 25600, 5120, 1024. Also divide the last of these by 2, ten times successively, and there will be produced 512, 256, 128, 64, 32, 16, 8, 4, 2, 1. Moreover all these numbers are logarithms.''

Thereupon let us seek for the common numbers which correspond