This version must have been scanned from an original pamphlet and turned into text by a computer because it has so many errors it is barely understandable. For example the letter s is often rendered as f or t or (. Some letters are rendered as numbers or symbols, and letters are missing making it guesswork to read.
I don't see how you can complain about something free, but I will say something. This was written by John Newton the slave trader captain who lived a redeemed life as a pastor. He is best known for writing Amazing Grace. I suspect if you are reading this you already know all that. They show a picture of the actual book. It has the very stylized print of the times. Unfortunately when they scanned the document the words are just about unreadable. It would be a relatively easy fix. If you could get it on some sort of editing program you could fix up about 95% of it. I think even I would be willing to give it a try.
It's a good book, but for research only, not for reading pleasure. It does give good insight, however, into the life of John Newton (author of Amazing Grace) and his part in the Atlantic Slave Trade. "Who wudda thunk it?"