Photographer Thomas E. Gilson and his brother William, a writer, each independently developed a fascination with old gravestones. Their joint project, “Carved in Stone: The Artistry of Early New England Gravestones” (Wesleyan) is an eerie photo book, one that quietly works on you. The carvings — most completed between 1650 and 1810 — depict angelic faces and macabre beings. Scattered among the more than 80 duotone photographs are writings from religious leaders of the time, many of the fire-and-brimstone ilk. Stare at the stone faces, William writes, and you wonder whether they are trying to make contact.