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.

An Explanation.

The propositi∣on

Princip.	Interest	L	S	D
100	5. 12. 6	543	13	4
Products of in∣terests per cent. per ann.	2718	6	8
271	16	8
67	19	2
The totall is	3058	2	6
Interest in respect of time	1529	1	3
764	10	7 ½
(A)	L 22	93	11	10 ½
5 l 12 s 6 d		20
5 L	S 18	71	months 9
½	10 ss	D 8	62	B 6	½
¼	2 ss 6 D	Q 2	½	B 3	½

being stated (as in the head of the table) multi∣ply the principal by the greatest denomination of interest, viz. 5 L, as in the table at A, according to the prescribed rules of practise, lib. 2. paragr. 9. quest. 4. for the 10 ss take half the principall, and for the 2 ss 6 D ⅛ or ¼ part of the last, so you will produce these 3 numbers 2718 L 6 ss 8 D. secondly, 271 L 16 ss 8 D. and thirdly, 67 L 19 ss 2 D. the totall is 3058 L 2 ss 6 D to be divided by 100 L, if forborn a year; but the term of time here is but 9 moneths, as in the table at B, which I divide into two parts, viz. 6 M.

and 3 M. then take half the totall, that is, 1529 L 1 ss 3 D, and for 3 moneths the half of that 764 L 10 ss 7 ½ D. the totall is 2293 L 11 S 10 ½ D, to be divided by 100 L. now proceed according to the former examples, and you will find the interest de∣manded 22 L 18 S 8 D 2 ½ Q. the proposition solved.

If this question had depended on moneths, weeks, and dayes, you must have taken proportio∣nall parts, and proceed, as before is specified; so there needs no more examples for the ingenious, to whom all other questions (in the rules of pra∣ctise) will be direct, and indirect for others, to in∣cumber their understandings with multiplicity of wayes in this kind, therefore I will onely shew you the discount of money, and proceed to Decimall Tables of compounded Interest.