The illustrations in Bryant F. Tolles Jr.’s Summer by the Seaside: The Architecture of New England Coastal Resort Hotels, 1820-1950 give a powerful sense of what has been lost. Vintage photographs, etchings, and architecturalplans whisk readers along the New England coast, past one elegant structure after another, some of them veritable Versailles, only in Queen Anne or Second Empire style, with verandas, shingled towers, and rows of top-floor dormers. It’s enough to make a preservationist weep, particularly one familiar with what’s replaced them.