2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/127303We prove that for 2-bridge knots, the diameter, D, of the set of boundary slopes is twice the crossing number, c. This constitutes partial verification of a conjecture that, for all knots in S^3, D is at most 2c.21 pages, 7 figures. v2 - No changes - we only wish to note that this is an early version of a paper to appear in The Osaka Journal of MathematicsGeometric Topology57M25 (Primary), 57M27 (secondary)text