Just finished reading this, and I found it thoroughly enjoyable. Written by the author of 'Voyage', 'The Time Ships,' and several other AH works, the POD is that a small comet impacts in Antarctica, and inside it is antimatter (although it's never called that) locked magnetically away from touchign normal matter, until the ice melts...then BLAM!
The British stake the meteor, and use the anti-matter in everything from proto-nuclear warheads in the Crimean War, 'nuclear' missiles used to keep Prussia and France at bay, and to fuel a voyage to the Moon (this is the main focus of the story).
The British stake the meteor, and use the anti-matter in everything from proto-nuclear warheads in the Crimean War, 'nuclear' missiles used to keep Prussia and France at bay, and to fuel a voyage to the Moon (this is the main focus of the story).