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.

The Theorem.

All bodies whose length is a straight line, right angled with either basis, the superficial content multi∣plied by the length (in the same denomination) will produce the solid content in inches, feet, yards, &c. as it shall be required.

First for the Cylinder A B C, whose length A C is supposed 30 feet, the Diameter A B or C D 3 ½ feet, that is 7 half feet; by the last Probleme you will find 38 ½ which divided by 4 (as in lib. 1. pa∣rag. 5.) the quotient will be 9 ⅝ or 77/8 square feet for the basis, which multiplied into the length 30 feet, the product will be 288 ¾ feet, the solid con∣tent of that Cylinder, as in the figure does ap∣pear.

If this round and long body were a tree with the bark taken off, and intended for board, slit work or building timber; in all such cases (according to common custome) a fourth part of the cir∣cumference is taken for the square of all such timber, called Girt Measure, which square multiplied by it self, and that product in the

length (of the same denomination) will shew the totall content: As for example, admit the Cylin∣der were the trunk or body of a tree thus to be measured be the former Probleme, the circumfe∣rence will be found 22 half feet, that is 132 in∣ches, the fourth part of which girt is 33 inches, whose square 1089 multiplied into the length, viz. 30 feet, that is in inches 360, the product will be then 392040, which divided by the cube of 12, the number of inches in a solid foot, viz. 1728, the quotient will be 226 1512/1728, or reduced to 226 ⅞ feet, the true content required according unto cu∣stomary measure for timber to be squared.

If the bark be on, as in Ash, Elm, or any timber fell'd in the winter season, it is as the buyer and sel∣ler can agree, or referr'd to custome, which in some places abating one inch in the square found, and for old Elms 1 ½ inch, in other places abating a tenth part of the solid content so measured, that is, allowing 1 foot in 10. of these two wayes both are indifferent in timber, that is 17, 18, 19, or 20 inches square, but in small timber an inch abated in the girt is too great an allowance, and too little when the timber is very great; but here I will not prescribe you either way, for a foot allowance in 10 hath as great an errour as the other, but contrary to the former, when one is too little, the other is too much; so I will write no more of this but caveat emptor.