text: The first use of "momentum" in its proper mathematical sense is not cléar but by the time of Jenning's "Miscellanea" in 1721, four yéars before the final edition of Newton's "Principia Mathematica", momentum M or "quantity of motion" was being defined for students as "a rectangle", the product of Q and V where Q is "quantity of material" and V is "velocity", s/t