On the Rectification of the Hyperbola by Means of Two Ellipses; Proving That Method to Be Circuitous, and Such as Requires Much More Calculation than Is Requisite by an Appropriate Theorem: In Which Process a New Theorem for the Rectification of That Curve Is Discovered. To Which Are Added Some Further Observations on the Rectification of the Hyperbola: Among Which the Great Advantage of Descending Series over Ascending Series,in many Cases,Is Clearly Shown; and Several Methods Are Given for Computing the Constant Quantity by Which Those Series Differ from Each other.