Via Ptak Science Books, a proposal to float Manhattan into the adjacent Hudson River and seemingly into the Atlantic. “Robert Grosvenor had a delectable and memorable idea for a project in 1975: testing the sea-worthiness of Manhattan island. Grosvenor (b. 1937) was a well-known kinetic sculptor in Manhattan by the time of his detaching-Manhattan idea… “

:: image via Ptak

The project is somewhat satirical, and shown in some of the graphic play to reinforce the specifics of the proposal. More from Ptak: “I do though like the simplicity of the presentation of the project, right down to the “Step 2” of preparation, which was the umbilical snipping of the bedrock of Manhattan and the attachment of the “flotation collar”, which, I guess, would allow it to be moved around so long as flotation devices were attached. “

:: image via Ptak

The project comes from what sounds like a fascinating book Unbuilt America, by Alison Sky and Michelle Stone -shows plans of buildings and monuments, that were planned but never built, throughout the first two centuries of the history of the United States. Thanks to @SpaceSyntaxGirl for the heads up on this one!