Late Dean of the College of Mechanics and Engineering of the Univ. of Wisconsin;
Formerly Civil Engineer on the U. S. Lake and Mississippi River
Surveys; Member Inst. Civil Engineers; Member of the
American Society of Civil Engineers, etc., etc.

SIXTEENTH EDITION, REVISED AND enlarged.

TOTAL ISSUE THIRTY-ONE THOUSAND.

NEW YORK:

JOHN WILEY & SONS.

LONDON: CHAPMAN & HALL, LIMITED.

PREFACE TO THE SIXTEENTH EDITION.

THE principal changes in this edition are the following: (1) Many changes in Chap. XIV on Geodetic Surveying, especially concerning base-line measurements and precise leveling, to adapt these portions to the recent greatly modified practices of the U. S. C. & G. Survey.

(2) A new Table XII has been computed (pp. 814, 815), for the years 1902-1910. This table gives the azimuth of Polaris for all hour-angles, and for all latitudes from 30° to 50°.

(3) Several minor changes and corrections have been made, notably on p. 468, in reference to the shrinkage of earthwork.

MADISON, January, 1902.

J. B. J.

PREFACE TO THE FIFTEENTH EDITION.

THE principal changes in this edition are the following: I. A new field method of determining the refraction correc tion to apply to the declination setting in solar azimuth work is given in Art 53a. This method was devised by G. C. Comstock, Professor of Astronomy in the University of Wisconsin.

2. A description of the slide-rule, with illustrative examples of its use, is given in Art. 156a. While the author has long been a constant user of slide-rules of all kinds, he had not thought to include it in a description of surveying instruments. It is now introduced here simply because its use is not taught elsewhere in our engineering schools.

3. Various improvements in the field methods of surveying with the transit and stadia, in order to increase the accuracy of this kind of work. These are found in the new articles 200a, 201, 218, 218a, all of which have been prepared by L. S. Smith, Assistant Professor of Topographical and Geodetic Engineering in the University of Wisconsin.

4. Chapter XI, on Mining Surveying, has been entirely rewritten by Prof. Robert S. Stockton, E.M., of the Colorado State School of Mines, Golden, Col., and by Mr. Edward P. Arthur, Jr., E.M., U. S. Deputy Mineral Surveyor, Cripple Creek, Col. Both these gentlemen are accomplished mining and mineral land surveyors, and one of them is an experienced teacher. It is believed, therefore, that this chapter has been

iv

much improved and is better suited, both for instruction and for field purposes, than the former chapter on this subject.

5. A new Appendix B, being the latest Manual of Instructions for the Survey of Mineral Lands. This has been brought up to date, 1899, and is much more full and complete than the former Appendix B.

6. A new Appendix I, which is a reprint of the latest Rules for Restoring Lost Corners as issued by the General Land Office at Washington. This is a very important addition.

It is thought that these changes and additions will considerably enhance the value of.a work which has secured and still retains the favor of both the surveyors and teachers of surveying at home and abroad to a degree far beyond the author's fondest hopes when he undertook the work some fifteen years ago.

The author's desire and purpose to keep this work fully abreast of the best American practice is his only excuse for the numerous additions and changes which have been made in the various successive editions.

MADISON WIS., January, 1900.

J. B. J.