In 1975, artist Richard Haas renewed the building at 112 Prince Street in Manhattan by covering its blank brick side with a five-story mural emulating the cast-iron architecture of its facade. Only two of the windows are real.

Another inspiration by Haas.

In 1961 Italian artist Piero Manzoni offered art buyers 90 tins of his own excrement, signed and numbered, each sold by weight at gold’s daily market price.

That would have been a good investment. A tin that would have cost $37 in 1961 was auctioned by Sotheby’s for $67,000 in 1991 — outperforming gold more than seventyfold.

Architect Robert Venturi got a tricky assignment in 1976: The National Park Service wanted to commemorate Ben Franklin’s residence in Philadelphia, but Franklin’s house had been demolished in 1812 and no record of its appearance had survived.

“There were fire insurance descriptions and archaeological remains of the house, so you could tell the exact configuration of the walls, and there were letters about the house exchanged between Franklin and his wife while he was in London and the house was in construction,” Venturi said. “But, with so little visual information, the Park Service was pretty easily persuaded not to try to reproduce the house.”

He solved the problem with a “ghost house” outlining the dimensions of the original house with a steel armature. “The aim was to create a delightful open place in the center of the dense texture of the city,” he said. “So the courtyard became a pleasant neighborhood amenity for people who live there, as well as for tourists.”

In 1965, sculptor Claes Oldenburg proposed building a colossal Good Humor bar on Park Avenue in Manhattan. All the traffic would have to be routed through a bite in the bar’s corner.

He also proposed replacing the Statue of Liberty with a giant electric fan and the Washington Monument with a pair of scissors.

The fan, he said, would guarantee workers in lower Manhattan a “steady breeze.” “You can also think of the Fan as a sort of substitute image of America. The suggestion is probably there but I haven’t drawn a conclusion.”

In 1766, French draughtsman Charles-Louis Clérisseau painted a room in the Trinità dei Monti convent in Rome to resemble a ruin, complete with a fallen ceiling and broken walls. A table was disguised as a damaged cornice, a desk as a shattered sarcophagus, and the kennel of the monks’ dog became a toppled urn.

“Building ruins in Rome might seem a waste of effort,” writes Robert Harbison in The Built, the Unbuilt, and the Unbuildable, “but the point was that one could comfortably inhabit this one, getting all the beauty of disorder without the inconvenience.”

For a 1793 treatise on the principles of Gothic architecture, Scottish architect Sir James Hall built an example using natural materials:

The wicker structure, as shewn in the frontispiece, was formed according to the plan of the cloister of Westminster Abbey, by a set of posts of ash about three inches in diameter thrust into the ground, with a set of willow rods of about an inch in diameter applied to them, the whole being conducted as already fully described. The construction answers perfectly well in practice, and affords a firm support for the thatch.

“The summit of the roof within is about eight feet high,” he added, “so that a person can walk under it with ease.”

A cowshed shaped like a cow, by the enigmatic French architect Jean-Jacques Lequeu, 1795. He labeled it simply “The Cow Byre faces south on the cool meadow.”

Elsewhere he proposed a henhouse shaped like an egg. Perhaps he was simply literal-minded.

In 1980, artist Tom Van Sant arranged 90 mirrors in the Mojave Desert at angles precisely calculated to overexpose the sensors on NASA’s Landsat II satellite 600 miles overhead and produce the image of a human eye 2.5 kilometers wide.

Two years later Van Sant commissioned the National Research and Resource Facility for Sub-Micron Structures at Cornell to etch the image of an eye a quarter-micron wide into a salt crystal:

The first image was 100,000 times larger than a human eye, the second 100,000 times smaller, two renderings of the same image that differ in scale by a factor of 10 billion.

“So the same artist who made the smallest drawing ever has also made the largest,” Richard Feynman told an audience. “Let’s go up another scale, the same amount again, another hundred thousand, and then try to draw an eye: Where would we have to draw it? Well, it turns out that it’s there — it’s a beautiful eye in the heavens, namely Saturn with her rings!”

More information at Van Sant’s website.

On learning that weather erodes granite one inch every 100,000 years, sculptor Gutzon Borglum added an extra three inches to each president’s features on Mount Rushmore.

“Three inches would require 300,000 years to bring the work down to the point that I would like to finish it,” he said. “In other words, the work will not be done for another 300,000 years, as it should be.”

(Thanks, Matt.)