Peirce's logic of continuity is explored from a double perspective: (i) Peirce's original understanding of the continuum, alternative to Cantor's analytical Real line, (ii) Peirce's original construction of a topological logic -- the existential graphs -- alternative to the algebraic presentation of propositional and first-order calculi. Peirce's general architectonics, oriented to back-and-forth hierarchical crossings between the global and the local, is reflected with great care both in the continuum and the existential graphs.