Page 54
WE will here advertise the Reader, that tho the Names 〈◊〉〈◊〉 duplicate & triplicate Reasons, &c. are chiefly appropriate to Geometrical Proportionality, yet the Moderns have also accom∣modated them to Arithmetical also; as e. g. That Arithmetic•• Progression is called Duplicate, whose Terms are the Squares 〈◊〉〈◊〉 Numbers Arithmetically Proportional (e. g. 1, 4, 9, 16, 25 &c.) and Triplicate, whose Terms are Cubes, (&c. as 1, •• 27, 64, &c.