I really enjoyed the Island in the Sea of Time series. I thought the use of firearms was quite thoughtful as the Natucket folks had to reinvent firearms. I once talked to Stirling and told him that Texas wouldn't have turned in their firearms so they could be destroyed in a fire. He ackknowledged that was a plot device to eliminate most of the available modern firearms. He has a new series out about the US where the same event that displace Nantucket leaves the world with a changed physics that disrupts electricity and gunpowder. Waiting to see the reviews or get it from the library.