Reading the script on old documents can be a challenge.  Genealogy Today has a nice article concerning deciphering old documents.

All documents were handwritten until the end of the 1800s when typewriters became available.  Sometimes the older documents are more readable than the first mechanically produce documents.  [Only an expert could change a ribbon.]

Paper may have been scarce and ink was handmade.  Each batch of ink varied from the others.  The part of the document you are interested in will be the one when he needed to make a new batch of ink and was stretching what he had. 

Some tips to help you.

• Read slowly and be patient making sure that the words make sense.
   
• Don't try to do a document all in one sitting.  Go back when you have rested eyes and an idea of this guys style.
   
• Make a couple of photocopies of the document.  This allows you to put one in the file and write on the other as you transcribe.
   
• Use a  magnifying glass and good light.
   
• Use letters from words in the document that you can read to decipher the letters in the words you are having trouble with. One way is to start by looking for dates, which are usually  in genealogical documents. Use the letters in the month, day of the week, etc. to help determine the writer's style.
   
• Look at the entire word.  Often you can figure out what the letters are after you know what the word is.
   
• If you are not sure of your transcription in a certain [place] put your best guess in brackets.
   
• Keep in mind that words were spelled differently in older documents - especially personal names and place names. You will often find them spelled differently in different parts of the document.
   
• Transcribe the document exactly as it is written - spelling and all.
   
• Keep a copy of the document with your transcription.  When you wish to share your transcription you can send along a copy of the original.