Hi folks, I have two questions: 1.- I am reading his Method of fluxions and when he writes x with a dot over the letter, Does he mean the differential of x, or what we say dx? In other words, Is that an infinitesimal quantity "smaller than any other fixed number"? I ask because I have read in some web pages that x dot meant dx/dt. 2.- In the entire Principia it is posible to find a geometric representation of ininitesimal quantities, Is there any math book dedicated exclusively to explain how to represent graphically differentials on geometric figures? Thanks!!!!!!!