Strange OCR technology

I've been going through some research on learning vocabulary and I've found nothing really interesting except one strange page. Somebody decided to put online an essay written in the 17th century by an early linguist analyzing ontology and how each language produces it. It is a very interesting text, but the most interesting about it is the apparent OCR technology that was used. See it for yourself.

It does strange tranlation of numbers like "2" into "To"... "4" into "For"... And also sometimes changes the text. Have a look and try to imagine what can be behind the technology. I'm almost thinking it is a speech recognition software with someone dictating it...