X 



CONTENTS. 



Colorado and Gila rivers _ ^ _ j28 129 



Tabulated distances along and near the boundary line between the United States and Mexico, from the Pacific ' 



ocean to the Gulf of Mexico, by Lieut. Michler _ _ ^__^ 171_ 



133 



CHAPl^E VIII. 



asteoxomicaIj a\d geodetic work. 



Preface 



138 



Determination of boundary line from the initial point on the Pacific ocean to junction of the Gila and Colorado. _ 138-166 

 Determination of boundary line from Kio Colorado to intersection of 111th meridian west of Greenwich and 



parallel 310 20' N _ ___ 1C6-174 



Determinations of the boundary line along parallels 31o 47' and 31° 20' N._ _ 175-190 



Boundary line formed by Rio Grande... _ 191-241 



Tabic of latitudes and longitudes of points on and near the boundary line between the United States and Mexico.. 242-245 



CHAPTER IX. 



METEOEOLOGT. 



Abstract of results from meteorological records 



Barometric heights 



Magnetic observations 



Declination and inclination 



Abstract of observations for horizontal intensity _ 251 



249 

 249 

 250 



250 



General table of results 



252 



Discussion of lines of equal magnetic declination, dip, and horizontal intensity..... 253 



Observations of declinations 

 Isogonic lines 



Observations of dip ^ . . . . 



Isoclinal lines ._ 



Horizontal intensity _ . 



254 

 255 



256 



257 

 257 



LIST OF MAPS 



SURVEYS 



engeavj:n^gs on steel. 



OENKRAL MAP OF TUK COUKTRY WEST OF TUB MISSISSIPPI, ON A SCALE OF ExnrJrnr 



Military plaza, San Antonio, (Frontispiece.) 

 Ojos de los Alamos Viejos 



Bto Grande, near Frontcra 

 Brownsville, Texr 



Las Isletas, fulls of Presidio de Kio Grande . . . 



Military colony, Piedras Negras, opposite Fort Duncan, Texas 

 Eio San Pedro, or Devil's river, above second crossing 



Limpia, Wild Rose Pass 



1 to 32, (inclusive,) outline sketches of views along the boundary line from the Eio Bravo to the 111th meridian 

 of longitude _ 



^^ " ^^ ^* ^^ ^* ^" ^* ^* ^* H •* np 4v ^4 ^B ^^ ^H ^H ^H, ^^ ^B ^^ ^- ^^ . 



33 to 64, (inclusive,) outline sketches of views along the boundnry line from the 1 1 1th meiidian of longitudeto the 

 junction of the Gila and Colorado. 



Page. 

 44 



46 

 60 



68 

 72 

 42 

 84 



97-101 



101-125 



