Analog: May 1965 (Digest-sized: 5-1/2" by 7-3/4")
Cover by John Schoenherr (for “Trouble Tide.”)

Serial: "The Prophet of Dune" (Conclusion) by Frank Herbert.

Novelette: “Trouble Tide” by James H. Schmitz (a "Nile Etland" story - related to The Demon Breed, serialized as "The Tuvela.")

Stories "Planetfall" by John Brunner
"The Captive Djinn" by Christopher Anvil.

Science: "Magnetohydrodynamics" by Ben Bova.