SPECIAL CALCULATION TABLE FOR THE BLIND
(2-DIGIT WHOLE NUMBER STEP-LOGARITHMS)
BY L. HARTFORD VAN DYKE, JR.
OCTOBER 3 1979

If the logarithms of the prime numbers 2, 3, 5 and 7 are expressed as continued fractions and then tabulated as ratios, the following table of step-logarithms is obtained:

N Log a N N Log a N N Log a N N Log a N
1 0 4 62 7 87 10 103
2 31 5 72 8 93 11 107
3 49 6 80 9 98 12 111

Other logarithms are easily obtained. For example

Log a 4.2 = log a 6 x 7/10 = log6 + log7-log10.

Therefore

log a 4.2 = 80 + 87 - 103 = 64.

This results in a simple duplex table, in which each steplog column is 31 greater than the steplog column to its left.

N LgsN N LgsN N LgsN N LgsN
1 0 2 31 4 62 8 93
''' ''' ''' ''' ''' ''' ''' '''
1.5 18 3 49 6 80 12 111
''' ''' ''' ''' ''' ''' ''' '''
2 31 4 62 8 93 16 124

For more information, write Harford Van Dyke, P.O. Box 3100, Battle Ground, Washington. 98604 (See Author's Monographs, and Books)

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