CONTENTS. 
PREFATORY NOTE. 
No. 1. 
EXTRACT FROM THE ANNUAL REPORT OF THE SECRETARY OF WAR, 
DECEMBER, 1855. 
No. 2. 
REPORT UPON THE PROGRESS OF THE PACIFIC RAILROAD EXPLORA¬ 
TIONS AND SURVEYS, NOVEMBER, 1855. 
BY CAPTAIN A. A. HUMPHREYS, 
CORPS OP TOPOGRAPHICAL ENGINEERS. 
No. 3. 
EXTRACT FROM THE ANNUAL REPORT OF THE SECRETARY OE WAR, 
DECEMBER, 1856. 
No. 4. 
REPORT UPON THE PROGRESS OE THE PACIFIC RAILROAD EXPLORA¬ 
TIONS AND SURVEYS, NOVEMBER, 1856. 
BY CAPTAIN A. A. HUMPHREYS, 
CORPS OF TOPOGRAPHICAL ENGINEERS. 
No. 5. 
TABLE EXHIBITING THE COMPARATIVE LENGTHS, COST, ETC., OE THE 
DIFFERENT ROUTES, WITH EXPLANATORY REMARKS. 
BY CAPTAIN A. A HUMPHREYS, 
CORPS OP TOPOGRAPHICAL ENGINEERS 
