Letters from Saffron-Walden the Generalls head quarters, : by way of apologie and vindication of the army under his Excellency Sir Thomas Fairfax, of some late groundlesse aspersions cast upon them. Together with a true account of the proceedings and resolutions of that army upon the late resolves and declaration of the Parliament concerning the petition of his officers and souldiers in the army, to his Excellency Sir Thomas Fairfax. Also the copie of a second petition from the county of Essex, intended to both the Houses of Parliament.