2. BIENNIAL REPORTS. 



The Survey has published three biennial reports, which relate to admin- 

 istrative affairs only and contain no scientific matter. 



First Biennial Report of the Commissioners of the Geological and Nat- 

 ural History Survey. 1899. Pp. 31. 



Second Biennial Report of the Commissioners of the Geological and 

 Natural History Survey. 1901. Pp. 44. 



Third Biennial Report of the Commissioners of the Geological and Nat- 

 ural History Survey. 1903. Pp. 35. 



3. HYDROGRAPHIC MAPS. 



There have been prepared hydrographic maps of the principal lakes of 

 southern and eastern Wisconsin. This work is in charge of L. S. Smith, 

 Assistant Professor of Topographical Engineering, University of Wis- 

 consin. 



The following maps are now ready: 



Size of Plate, 

 Inches. 



No. 1. LakeGeneva 17.5x10.8 



No. 2. ElkhartLake 15.5xJ3.1 



No. 3. LakeBeulah 22.5x20.0 



No. 4. Oconomowoc-Waukesha Lakes 29.8x19.1 



No. 5. The Chain of Lakes, Waupaca 21.7x20.6 



No. 6. Delavan and Lauderdale Lakes .... 22.5x16.8 



No. 7. GreenLake 26.0x17.8 



No. 8. LakeMendota 23.7x19.5 



No. 9. BigCedarLake 18.0x13.5 



No. 10. LakeMonona 17.6x17.3 



Scale, Inches Contour In- 



per mile, terval, Feet. 

 2 10 



5 10 



6 10 

 2 10 

 6 10 

 4 10 



6 



2.9 



4 



In all of these maps the depth of the ' lakes is indicated by contour 

 lines, and by tints in all except No. 1. They are sent on receipt of 15 cents 

 each except Nos. 4 and 8, for which 20 cents are required. They may be 

 had either mounted in a manilla cover, or unmounted. 



All correspondence relating to the s urvey should be addressed to 



E. A. BIRGE, Director, 

 Madison, Wis. 



