Sentence:  The Design on "Lequesne", supposing all to have been honest that produced it, could have taken it's Rise from nothing but want of Knowledge in common Geography: No Eye that follows the Course in the Map, which is always taken by the <WSD>"Canadian French</WSD>" from "Quebec" to Fort "Lequesne", but must be necessarily convinced that the taking "Niagara" would have answered all the Purposes of possessing that and "Lequesne". 
Meaning of the word marked with <WSD> tags:  French Canadians, collectively.