ABSTRACT. Every countable transitive model M of ZF (without choice) has an ordinal preserving extension satisfying ZF, of power MnO/i" An aPPucation t0 infinitary logic is given.Any transitive model M of ZFC with countably many ordinals must be countable. The situation is quite different when the axiom of choice is dropped.The first examples of transitive models of ZF of power Wj with countably many ordinals were constructed by Cohen. Later Easton, Solovay, and Sacks showed that every countable transitive model of ZF has an ordinal-preserving extension satisfying ZF, of power 2". We prove here that every countable transitive model M of ZF has an ordinal preserving extension satisfying ZF, of power 3Mno".Theorem 1 is probably in the folklore. However, the proof of its first part is apparently not standard. The method used in that proof and the combinatorial construction of §2 form the crux of the proof of the main theorem.