To the ninth article, which is this, “_If a body be moved by two movents at once, concurring in what angle soever, of which, one is moved uniformly, the other, with motion uniformly accelerated from rest, till it acquire an impetus equal to that of the uniform motion, the line in which the body is carried, shall be the crooked line of a semiparabola_,” you lift up your voice again, and ask, _what latitude? what diameter? what inclination_ of the diameter to the ordinate lines? If your founder should see this, or the like objections of yours, he would think his money ill bestowed. When I say, _in what angle soever_, you ask, _in what angle?_ When I say _two movents, one uniform, the other uniformly accelerated, make the body describe a semiparabolical line_; you ask, _which is the diameter?_ as not knowing that the accelerated motion describes the diameter, and the other a parallel to the base. And when I say _the two movents meet in a point, from which point both the motions begin, and one of them from rest_, you ask me _what is the altitude?_ As if that point where the motion begins from rest were not the vertex; or that the vertex and base being given, you had not wit enough to see that the altitude of the parabola is determined? When Galileo’s proposition, which is the same with this of mine, supposed no more but a body moved by these two motions, to prove the line described to be the crooked line of a semiparabola, I never thought of asking him what altitude, nor what diameter, nor what angle, nor what base, had his parabola. And when Archimedes said, let the line A B be the time, I should never have said to him, _do you think time to be a line_, as you ask me whether I think impetus can be the base of a parabola. And why, but because I am not so egregious a mathematician, as you are. In this giddiness of yours, caused by looking upon this intricate business of motion, and of time, and the concourse of motion uniform, and uniformly accelerated, you rave upon the numbers 1, 4, 9, 16, &c. without reference to any thing that I had said; insomuch as any one that had seen how much you have been deceived in them before, in your scurvy book of _Arithmetica Infinitorum_, would presently conclude, that this objection was nothing else but a fit of the same madness which possessed you there. My tenth article is like my ninth; and your objections to it are the same which are to the former. Therefore you must take for answer just the same which I have given to your objection there.