THE WHOLE CLEARLY DEMONSTRATED AND ILLUSTRATED BY A LARGE NUMBER PARTICULARLY ADAPTED TO THE USE OF SCHOOLS. BY JOHN GUMMERE, A. M. FELLOW OF THE AMERICAN PHILOSOPHICAL SOCIETY, AND CORRESPONDING MEMBER FOURTEENTH EDITION, CAREFULLY REVISED, AND ENLARGED BY THE ADDITION OF THEODOLITE LEVELLING, AND TOPOGRAPHY PHILADELPHIA: PUBLISHED BY KIMBER & SHARPLESS, No. 50, NORTH FOURTH STREET. Entered according to the Act of Congress, in the year 1838, by Kimber & Sharpless, in the Clerk's Office of the District Court of the Eastern District of Pennsylvania. PREFACE. THE following compilation originated in the belief that our schools are in want of a Treatise on Surveying, adapted to the methods practised in this country, and freed from the defects of the systems now in use. Notwithstanding the importance of the science, and the large number that make it an object of study, it is believed we are not in possession of a treatise on this subject, suited to the wants of the student. The works of Gibson and Jess are the only ones at present in general use; the former, though much the better of the two, is deficient in many respects. It may be sufficient here, merely to advert to its want of examples, which renders it entirely unsuitable for a school bork. From the latter, the student would in vain expect to become acquainted with the principles of the science, or the rationale of any of the rules, necessary in performing the various calculations.* In order to understand the principles of surveying, a previous knowledge of Geometry is absolutely necessary; and this knowledge will be best acquired from a regular treatise on the subject. In the demonstrations, therefore, throughout this work, the student is supposed to be acquainted with the elements of that science. The references are adapted to Playfair's Geometry, but they will in general apply equally well to Simson's translation of Euclid's Elements. As there are many who wish to obtain a practical knowledge of Surveying, whose leisure may be too limited to admit of their • Each of these works has lately gone through a new edition, in which considerable additions are stated to have been made. On examination, however, it does not appear, that those additions are such as to supply the deficiencies. The additions made to Gibson, consist principally of some nautical problems quite foreign to a treatise on Surveying. Those made to Jess, consist of a few extracts from Gibson, in one of which the Pennsylvania method of calculation is introduced, as being quite different from that given by Jess; whereas it is well known to be the method given by that author, and used, as well in the preceding, as in the subsequent part of his work. |
