

CONTENTS 



Page. 



Letter of transmittal xm 



Chapter 1. 



Introduction 1 



Surveys under the IT. S. Government 2 



Exploration of the Fort ieth Parallel 2 



Geologic and Geographic Survey of the Territories 2 



Geologic and Geographic Survey of the Rocky Mountain region 3 



Northern Transcontinental Survey 3 



Coast and Geodetic Survey 3 



Engineer Corps, U.S. Army 4 



General Land Office Surveys 4 



Surveys under State governments 4 



Massachusetts 4 



New York 5 



New Jersey 5 



Pennsylvania 5 



Railroad and other surveys 5 



Plan of the map of the United States 6 



Scale 7 



Scales of topographic maps of European nations 9 



Contour interval 9 



Features represented 9 



Size of sheets 10 



Geometric control 10 



Its accuracy 11 



Its amount 11 



Its distribution 14 



Sketching 14 



Chapter II. 



Classification of work 15 



Astronomic determinations of position 16 



Definitions 17 



Astronomical transit and zenith telescope 18 



Chronograph 19 



Field work 20 



