A brief state of the province of Pennsylvania : in which the conduct of their Assemblies for several years past is impartially examined, and the true cause of the continual encroachments of the French displayed, more especially the secret design of their late unwarrantable invasion and settlement upon the river Ohio : to which is annexed, an easy plan for restoring quiet in the public measures of that province, and defeating the ambitious views of the French in time to come : in a letter from a gentleman who has resided many years in Pennsylvania to his friend in London