А COMPLETE TREATISE ON THE Menfuration of Timber : CONTAINING, Besides all the rules usually given on the subject, PARTICULARLY THE NEW, EXPEDITIOUS, AND VERY ACCURATE METHOD SQUARE & ROUND TIMBER : ....WITH.... THE DESCRIPTION OF THE SLIDING RULE AND GUNTER's SCALE, THE WHOLE BEING ILLUSTRATED WITH EXAMPLES AT BY JAMES THOMPSON. TROY, (N. Y.) PRINTED BY WRIGHT, WILBUR STOCKWELL, FOR THEMSELVES AND THE AUTHOR. 1805. L. S. Ke 1912 27845 COPY RIGHT. DISTRICT OF NEW-YORK, ss. BE DE IT REMEMBERED, that on the eighth day of October, in the twenty-ninth year of the Independence of the United States of America, James Thompson, of the said District, hath deposited in this Office the title of a book, the right whereof he claims as author, in the words following, to wit: "A complete treatise on the mensuration of timber-Contain❝ing, besides all the rules usually given on the subject, some (( new and interesting improvements, particularly the new, ex"peditious, and very accurate method of calculating the contents "of square and round timber..... With the description of the "sliding rule and gunter's scale, so far as they relate to this art. "The whole being illustrated with examples at full length, and "is well adapted to the practical timber measurer. 66 BY JAMES THOMPSON." In conformity to the act of the congress of the United States, entitled "An act for the encouragement of learning, by securing "the copies of maps, charts, and books, to the authors and pro"prietors of such copies, during the time therein mentioned." Edward Dunfcomb, Clerk of the District of New-York. IN order to prevent the Publick from being imposed upon, by any spurious imitations of the following Treatise, or of the Tables contained therein-I have thought proper to distinguish such copies as are correct and genuine, by subscribing my name, James Thompson. PREFACE. THERE is not wanting a great variety of mathematical works wherein the menfuration of timber is fully explained; but thus it happens, that there is not extant a separate treatise on the art, in every refpe&t adapted to the ufe of the merchant, and to the general capacities of those who are otherwife concerned in the measurement of timber. The following is meant as an attempt of this kind, comprehending in a fmall pocket volume, of moderate price, all the practical rules, in an eafy, obvious manner→ fo that they may be fufficiently intelligible for common practice, even to those who have not had the advantage of a mathematical education. As the menfuration of timber requires the application of decimal arithmetick in all its parts, it has therefore been treated of, together with the extraction of the square and cube roots, as fully as is needful-and at least, as plainly as in any other book of the kind: Immediately after, is explained at confiderable length, the use of the line of numbers, on the gunter's fcale and fliding ruleboth inftruments being ufeful for finding the contents of timber, and is performed with great expedition. And as the method of calculating by duodecimals is very short in fome cafes, (whereas by decimal fractions the fame would be fomewhat tedious, on account of repetends,) I have examplified all the rules in the multiplication of feet and inches; which is all that the timber measurer requires. Having difcuffed the above mentioned branches, the subject then comes to be purely practical, and commences by treating, 1ftly, of board measure; 2dly, of reducing scantling to board measure; 3dly, of fquare timber; 4thly and laftly, of round timber. In all the cafes in each problem, there is at leaft one example wrought according to all the approved and common rules; and the operations are inferted at full length, in order that it may confpicuously appear, which is the fhorteft, plaineft, and moft accurate. The cuf tomary, or false method, is particularly pointed out; and on comparing it with the true method, it will be found to give the contents above the truth, on rectangular fquare timber whose breadth is greater than its thicknefs; and under the truth, on tapering fquare timber; and about one fourth part under the truth, on round timber. There are alfo other examples, with their anfwers according to the true and false methods. Following the problem of board meafure, there is a table exhibiting the fuperficial contents of boards from 3 to 30 inches in breadth, and from 7 to 30 feet in length. -Following the problem of reducing fcantling to board measure, there is an original table of the areas in fuperfi cial feet of fquares and parallelograms, for all fizes from 3. by 3, to 12 by 12 inches.-Following the problem of fquare timber, there is an original table of the areas of fquares in feet, or it is a table of the folid contents of prifms from 3 to 30 inches fquare, and 1 foot in length.--And following the problem of round timber, there is an original table of the areas of circles in feet; or, it is a table of the folid contents of cylinders from 10 to 141 inches in circumference or girt, and 1 foot in length. I Thefe tables are extended to fix decimal places; but in common practice, two or three will be fufficiently accurate; which will render the calculation of the contents of timber very eafy, and as expeditious as by any inftrument-and at the fame time much more to be depended on. At the end are added a number of questions, intended for practical exercifes to the learner, that he may farther improve himself in the problems and in the characters which are generally used in works of this nature. In the execution of this little treatise, I have received great affiftance from a number of mathematical works, particularly from thofe of Hutton, Ewing, Pyke and Mac Gregor, befides many other good writers on decimal arithmetick; the gunter's fcale and fliding rule have been confulted, and in feveral things, found of no small use. The feveral parts of the art have been handled more or lefs fully, according to their apparent practical imper tance; and it is hoped nothing is omitted which is either neceffary to the practitioner's understanding the reafons of his various operations, or materially ufeful for his affiftance in performing them.-At leaft, this was the end propofed, and pains have not been fpared in order to attain it but with what fuccefs, the candid judgment of the publick muft determine. |