The circumference of a graph G is the length of a longest cycle in G.
In this paper, we shall show that, if G is a 3-connected graph embedda
ble in the plane, the projective plane, the torus, or the Klein bottle
, then G has circumference at least (1/6) x \V(G)\(0.4) + 1. This impr
oves a result of Jackson and Wormald. (C) 1997 Academic Press.