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After‐burner flames do not have to be stabilized by means of ba'nes; and indeed the drag which solid flame‐holders exert on the tail‐pipe gases, even when re‐heat is not in operation, render them undesirable elements to have in a jet engine. For this reason there has been considerable interest in recent years in the use of air‐jets as flame‐holding devices; these have the advantage that they can be turned off when not in use. The first suggestion of this kind known to the reviewer was made in a S.N.E.C.M.A. patent of about 1953; experimental studies were carried out at Imperial College, the jets in question emerging from slots in the wells of the duct carrying the co bustible gas the method was found to work quite well. More recently, work in United States laboratories has concentrated on the use of jets injected in a direction opposed to that of the main stream; the present issue contains a report from the Stanford Research Institute on one investigation of this type. The reviewer has not heard of any practical application of jet flame‐holders so far; but certainly sufficient laboratory progress has been made to justify the attention of engine designers.