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DISTRICT OF MARYLAND, ss.
BE IT REMEMBERED, That on this Twelfth day of November, in the Forty-first year of the Independence of the United States of America, F. Lucas, Jun. of the said District, hath deposited in this office the title of a Book, the right whereof he claims as Proprietor; in the words following, to wit:
"A Treatise on Practical Surveying; which is demonstrated from its first principles. Wherein every thing that is Useful and Curious in that Art, is fully considered and explained.-by Robert Gibson.-Revised, Corrected and Adapted to the use of Schools, American Surveyors, &c. by John D. Craig.'
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 proprietors of such copies during the times therein mentioned." And also to the act, entitled, "An act supplementary to an act, entitled, “An act for the encouragement of learning, by securing the copies of maps, charts, and books, to the authors and proprietors of such copies during the times therein mentioned," and extending the benefits thereof to the arts of designing, engraving, and etching historical and other prints."
W.L. Cements lib.
THE present edition of Gibson's Surveying, being intended for the use of schools, as well as for the American reader and surveyor in general, several alterations have been made in various parts of the work. Useless calculations have been either abridged, or entirely omitted, and a number of new examples for calculating surveys, and dividing of land, substituted in their room. Different parts of those calculations are designedly omitted, for the better exercising of the learner. And it is presumed, the arrangement of the plates will. be found highly advantageous, both for the convenience of the reader and the preservation of the book. The press has been carefully corrected, and it is hoped that the work is as free of such errors as any publication of the kind.
THE word geometry imports no more than to measure the earth, or to measure land; yet in a larger and more proper sense, it is applied to all sorts of dimensions. It is generally supposed to have had its rise among the Egyptians, from the river Nile's destroying and confounding all their land-marks, by its annual inundations, which laid them under the necessity of inventing certain methods and measures to enable them to distinguish and adjust the limits of their respective grounds, when the waters were withdrawn. And this opinion is not entirely to be rejected, when we consider that Moses is said to have acquired this art when he resided at the Egyptian court. And Achilles Tatius in the beginning of his introduction to Aratus's Phænomena, informs us, that the Egyptians were the first who measured the heavens and the earth (and of course the earth first) and that their science in this matter, was engraven on columns, and by that means delivered to posterity.
It is a matter of some wonder, that though surveying appears to have been the first, or at least one of the first of the mathematical sciences, that the rest have met with much greater improvements from the pens of the most eminent mathematicians, while this seems to have been neglected; insomuch that I have not been
able to meet with one author, who has sufficiently explained the whole art in its theory and practice; for the most part, it has been treated of in a practical manner only; and the few who have undertaken the theory, have in a great measure omitted the practice.
These considerations induced me to attempt a methodical, easy, and clear course of Surveying; how far I have succeeded in it, must be determined by the impartial reader the steps I have taken to render the whole evident and familiar are as follow:
In section the first, you have decimal fractions, the square root, geometrical definitions, some necessary theorems and problems; with the nature and use of the tables of logarithm numbers, sines, tangents, and secants.
The second section contains plane trigonometry right angled and oblique, with its application in determining the measures of inaccessible heights and distances.
The third section gives an account of the chains and measures used in Great-Britain and Ireland; methods of surveying and of taking inaccessible distances by the chain only, with some necessary problems; also a particular description of the several instru ments used in surveying, with their respective uses.
The fourth section contains two methods of finding the areas of maps from their geometrical construction,