Socius mercatoris: or The merchant's companion: in three parts. The first, being a plain and easie introduction to arithmetick, vulgur and decimal, the extraction of the square and cube roots, with a table of 200 square roots, and their use in the resolution of square equations. The second, a treatise of simple and compound interest and rebate, with two tables for the calculation of the value of leases or annuities, payable quarterly, the one for simple, the other compound interest, at 6 per cent. per annum, with rules for making the like for any other rate. The third, a new and exact way of measuring solids in the form of a prismoid and cylindroid, with the frustums of pyramids and of a cone: whereunto is added, some practical rules and examples for cask-gauging. By John Mayne, philo-accomptant.

To the Ingenious Author, concerning his DECIMALS.

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SIr, by your Art, and Pythagorean Pen, I'd prove a Metempsychosis agen; And were His Soul of Decimals but made,

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As Plato's Soul o'th' world of Seven is said, I'd swear 'twas slunk to you; but that you shew

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More Skill than e're his rambling fancy knew. Let roving Rabbies praise their Seven and Four;

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We'l shew them Mysteries enough and more: The Heav'nly Orbs are Ten, their Motions all

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Conspire to make a perfect Decimal: This is their Musick, and they shall be thus,

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In spight of Tycho or Copernicus. 'Tis said the Muses are but Nine, but who

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(Rather than fail) cann't add Apollo too? Thus may we range the world, and quickly find,

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We all to th' number of our Fingers bind. Thus Logick all the wandring Species brings,

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And places under tenfold Heads of things. Thus I, to give the Author praise in all,

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Reduce my Verses to a Decimal.