"Above all things it must be considered, that the motion of descending grave bodies is not uniform, but departing from rest they go continually accelerating.. But this general notion is of no avail, if it be not known according to what proportion this increase of velocity is made; a conclusion that hath been until our times unknown to all Philoso­phers; and was first found out & demonstrated by the Academick [Galileo], our common friend, who in some of his writings not yet publish­ed... he proveth, how that the acceleration of the right mo­tion of grave bodies, is made according to the numbers uneven beginning ab unitate [from unity], that is, any number of equal times being assigned, if in the first time the moveable departing from rest shall have passed such a certain space, as for example, an ell, in the se­cond time it shall have passed three ells, in the third five, in the fourth seven, and so progressively, according to the following odd numbers; which in short is the same, as if... the [sums of] spaces passed are to each other, as the squares of their times."