Version 1.0
Originally published in 1992, this report is presented here in Portable Document Format.
Adobe Acrobat Reader 3.0 is required to view it.
If you wish to download the latest version of Acrobat Reader free of charge, click here.
If you already have Acrobat Reader 3.0 or later installed on your computer, click here to access the text (1 MB).
For more information about this report contact William D. Heran at wheran@usgs.gov