Marshall, R. B.  1867-1949 <br/><br/>
Results of spirit leveling in Pennsylvania, 1899 to 1911, inclusive. 
R. B. Marshall, chief geographer.  Work done in cooperation with the state. 
 - Washington,  Govt. Print. Off.,  1912. 
 - 164 p.  24 cm. 
 - U.S. Geological survey. Bulletin 515 .
 - United States.  Geological Survey.  Bulletin ;  515. .
<br/><br/> Includes index. 
<br/><br/><label>LCCN: </label>gs 12000790  
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Pennsylvania--Altitudes.
<br/><br/><label>LC Class. No.: </label>QE75  / .B9 no. 515