PREFACE. 
Gillespie’s “Land-Surveying” was first printed in 1851, for 
use in Professor Gillespie’s classes in Union College. It was 
published in 1855, and very soon became the standard authority 
on land-surveying. 
In the preface to the first edition Professor Gillespie says: 
“ Land-surveying is perhaps the oldest of the mathematical 
arts. Indeed, geometry itself, as its name—‘ land-measuring ’ 
—implies, is said to have arisen from the efforts of the Egyp 
tian sages to recover and to fix the landmarks annually swept 
away by the inundations of the Nile. The art is also one of 
the most important at the present day, as determining the title 
to land, the foundation of the whole wealth of the world. It 
is, besides, one of the most useful as a study, from its striking 
exemplifications of the practical bearings of abstract mathema 
tics. But, strangely enough, surveying has never yet been re 
duced to a systematic and symmetric whole. To effect this, by 
basing the art on a few simple principles and tracing them 
out into their complicated ramifications and varied applications 
(which extend from the measurement of ‘a mowing-lot’ to 
that of the heavens), has been the earnest endeavor of the 
present writer. 
“ The work, in its inception, grew out of the author’s own 
needs. Teaching surveying, as preliminary to a course of civil 
engineering, he found none of the books in use (though very 
excellent in many respects) suited to his purpose. He was, 
therefore, compelled to teach the subject by a combination of 
familiar lectures on its principles and exemplifications of its 
practice. His notes continually swelling in bulk, gradually be 
came systematized in nearly their present form. His system has 
thus been fully tested, and the present volume is the result.