FIVE-PLACE

LOGARITHMIC AND TRIGONOMETRIC

TABLES.

ARRANGED BY

G. A. WENTWORTH, A.M.,

AND

G. A. HILL, A.M.

BOSTON, U.S.A.:

PUBLISHED BY GINN & COMPANY.

1895.

HARVARD
COLLEGE
LIBRARY

Entered according to Act of Congress, in the year 1882, by G. A. WENTWORTH AND G. A. HILL, in the office of the Librarian of Congress at Washington.

J. S. CUSHING & Co.. PRINTERS, BOSTON.

INTRODUCTION.

1. If the natural numbers are regarded as powers of ten, the exponents of the powers are the Common or Briggs Logarithms of the numbers. If A and B denote natural numbers, a and b their logarithms, then 10a = A, 10° = B; or, written in logarithmic form,

2. The logarithm of a product is found by adding the logarithms of its factors.

3. The logarithm of a quotient is found by subtracting the logarithm of the divisor from that of the dividend.

4. The logarithm of a power of a number is found by multiplying the logarithm of the number by the exponent of the power.

5. The logarithm of the root of a number is found by dividing the logarithm of the number by the index of the root.

6. The logarithms of 1, 10, 100, etc., and of 0.1, 0.01, 0.001, etc., are integral numbers. The logarithms of all other numbers are frac

tions.