AN archaeological reconnaissance with the view of further investigation has been made recently by Dr. L. S. B. Leakey on two sites in East Africa. Of these, one, the ruins of Gedi, an ancient city of considerable extent, sixty-five miles north of Mombasa, is already scheduled under the Ancient Monuments Preservation Ordinance; the other is the large assemblage of stone-built dwelling-places and tombs at Engaruka in the Great Rift Valley in Tanganyika, to which attention was directed as a new discovery in June last of Mr. T. E. Wetherell. The ruins at Gedi, though situated at no more than fifty yards from the Mombasa-Malindi road at their nearest point, are so obscured by a tangle of tropical vegetation as almost to escape notice. Trees of considerable size growing on or in the ruined structures afford some gauge of the antiquity of the ruins. According to Dr. Leakey's report (The Times, October 11) future investigation will reap a rich harvest. Town walls, buildings and tombs alike afford evidence of at least two, and possibly three, distinct periods of construction. The materials used consist of dressed blocks of coral, built up with a hard mortar and plastered to a smooth surface. In places, where the dressing is unplastered, as on the arches over doors and windows, it is extremely fine. It is Dr. Leakey's opinion that the ruins may be those of an Arab or Persian settlement of considerable antiquity, the first settlement possibly dating so far back as the beginning of the Christian era.