The scales of commerce and trade: ballancing betwixt the buyer and seller, artificer and manufacture, debitor and creditor, the most general questions, artificiall rules, and usefull conclusions incident to traffique: comprehended in two books. The first states the ponderates to equity and custome, all usuall rules, legall bargains and contracts, in wholesale ot [sic] retaile, with factorage, returnes, and exchanges of forraign coyn, of interest-money, both simple and compounded, with solutions from naturall and artificiall arithmetick. The second book treats of geometricall problems and arithmeticall solutions, in dimensions of lines, superficies and bodies, both solid and concave, viz. land, wainscot, hangings, board, timber, stone, gaging of casks, military propositions, merchants accounts by debitor and creditor; architectonice, or the art of building. / By Thomas Willsford Gent.

RULE 2.

As 100 L sterling forborn the term of a year

Shall be in proportion to the last years Decimal,

So will the summe of the principal and interest

Be unto a Decimal for the succeeding year.

An illustration.

		Prin.	Decimal	Principal	Decim.
I		100 l	is to 106	so wil 1 l be to	1.060000
II		100 l	is to 1060000	so 106 l is to	1.123600
III	as	100 l	is to 1123600	so 106 l unto	1.191016
IV		100 l	is to 1191016	so 106 l unto	1.262477
V		100 l	is to 1262477	so 106 l unto	1.338226

In the construction of these tables, take an unite with what number of ciphers you please for the Radius, one place more then you intend to in∣scribe,

but of no necessity, as here 1,000,000, the seventh place being an integer, all the other to∣wards the right hand are fractions, or representing their places according to my third book of Artifici∣all Arithmetick: now for framing the first table (wherein the principal is forborn) adde the princi∣pal and interest together; the summe is here 106, annex 4 ciphers or points to it, equal to the Radi∣us, and it is a decimal fraction for the 1 L forborn a year; or by the first rule, as 100 L is to 106, the principal and interest allowed, so shall 1 L princi∣pal be in proportion to 1.060000, which is a mixt decimal fraction, and comprehends the 1 L princi∣pal, with the interest 06/100, and reduced is 1 ss 2 d 1 ⅗ q. but leaving it involved, as the encrease of the first year, all the rest will be discovered by the second rule successively, viz. as 100 L to 1.060000, so 106 the principal and interest to 1.123600, the decimal for the second year; then for the third year, as 100 L is to 1123600, so 106 in proportion to 1.191016 in the same manner of operation, you will find 1,262477 for the fourth year, and 1,338226, a proportional decimal fra∣ction comprehending 1 l principal forborn 5 years, with the compound interest of it, which is 6 ss 9 d, and not one farthing more: thus you may proceed to what number of years occasion shall require.