a. [f. as prec. + -AL.] = LOGARITHMIC. Logarithmical scales (see quot. 1727–41).
1631. H. Briggs (title), Logarithmicall Arithmetike.
1665–6. Phil. Trans., I. 215. The Logarithmical Tangent-line.
1727–41. Chambers, Cycl., Proportional scales, called also logarithmical scales, are the artificial numbers or logarithms, placed on lines, for the ease and advantage of multiplying, dividing, &c. by means of compasses, or of sliding-rules.
1728. Pemberton, Newton’s Philos., 145. That line … which is now commonly known by the name of the logarithmical curve.
1799. Young, in Phil. Trans., XC. 150. The inner circle L is divided into 30103 parts, corresponding with the logarithmical parts of an octave.
1812–6. Playfair, Nat. Phil., II. 47. Formulas … more convenient for logarithmical calculation.
1839. Hallam, Hist. Lit., IV. III. viii. § 8. 7. Thus reducing the error, which, strictly speaking, must always exist from the principle of logarithmical construction, to an almost infinitesimal fraction.
Hence Logarithmically adv., by the use of logarithms; in logarithmic proportions.
1760. Pemberton, in Phil. Trans., LI. 923. The present methods of computing logarithmically an angle from the three sides of a spherical triangle given.
1828. Hutton, Course Math., II. 328. Expressing this equation logarithmically.
1875. Jevons, Money, xxiv. 332. The ratios in which their gold pieces have changed would be calculated logarithmically.
