Giotto's circle, Apelles' lines, Chuang-tzu's crab

Simple, raw, sublime skill used to demonstrate artistic genius is an old topos. Three stories - Giotto's circle, Apelles'/Protogenes' lines and Chuang-tzu's crab:

Giotto draws a perfect circle for the Pope, told by Vasari:

Pope Benedict sent one of his courtiers into Tuscany to see what sort of a man he was and what his works were like, for the Pope was planning to have some paintings made in S Peter's. This courtier, on his way to see Giotto and to find out what other masters of painting and mosaic there were in Florence, spoke with many masters in Sienna, and then, having received some drawings from them, he came to Florence. And one morning going into the workshop of Giotto, who was at his labours, he showed him the mind of the Pope, and at last asked him to give him a little drawing to send to his Holiness. Giotto, who was a man of courteous manners, immediately took a sheet of paper, and with a pen dipped in red, fixing his arm firmly against his side to make a compass of it, with a turn of his hand he made a circle so perfect that it was a marvel to see it Having done it, he turned smiling to the courtier and said, "Here is the drawing." But he, thinking he was being laughed at, asked, "Am I to have no other drawing than this?" "This is enough and too much," replied Giotto, "send it with the others and see if it will be understood." The messenger, seeing that he could get nothing else, departed ill pleased, not doubting that he had been made a fool of. However, sending the other drawings to the Pope with the names of those who had made them, he sent also Giotto's, relating how he had made the circle without moving his arm and without compasses, which when the Pope and many of his courtiers understood, they saw that Giotto must surpass greatly all the other painters of his time.

More on Giotto: The story comes from Vasari, Lives of the Painters, Sculptors and Architects (allconsuming, amazon.co.uk). Tom Phillips revisited (and remeasured) Giotto in his Fifty attempts to paint a freehand circle, 1974. Update, Dec 2003: Lego likes Giotto's demonstration.

Apelles and Protogenes split lines in a test of skill, told by Apollinaire:

We all know the story of Apelles and Protogenes, as it is told by Pliny.
It provides an excellent illustration of aesthetic pleasure independent of the subject treated by the artist [...] Apelles arrived one day on the island of Rhodes to see the works of Protogenes, who lived there. Protogenes was not in his studio when Apelles arrived. Only an old woman was there, keeping watch over a large canvas ready to be painted. Instead of leaving his name, Apelles drew on the canvas a line so fine that one could hardly imagine anything more perfect.
On his return, Protogenes noticed the line and, recognizing the hand of Apelles, drew on top of it another line in a different color, even more subtle than the first, thus making it appear as if there were three lines on the canvas. Apelles returned the next day, and the subtlety of the line he drew then made Protogenes despair. That work was for a long time admired by connoisseurs, who contemplated it with as much pleasure as if, instead of some barely visible lines, it had contained representations of gods and goddesses.

More on Apelles and Protogenes: Apollinaire's version is in 'On the Subject of Modern Painting', originally published in Les Soirées de Paris, February 1912. The story was originally told by Pliny in Natural History (allconsuming, amazon.co.uk). Natural History is being translated and annotated online.. See also: Deceptions and Illusions: Five Centuries of Trompe l'Oeil Painting at Washington DC's National Gallery of Art, which mentions the realism of the panels painted by Ap and Prot.

Chuang-tzu takes ten years to draw the perfect crab, told by Calvino in 'Quickness', Six Memos for the Next Millennium:

Among Chuang-tzu's many skills, he was an expert draftsman. The king asked him to draw a crab. Chuang-tzu replied that he needed five years, a country house, and twelve servants. Five years later the drawing was still not begun. "I need another five years," said Chuang-tzu. The king granted them. At the end of these ten years, Chuang-tzu took up his brush and, in an instant, with a single stroke, he drew a crab, the most perfect crab ever seen.

More on Chuang-tzu: Italo Calvino tells the story in 'Quickness', in Six Memos for the Next Millennium, 1988 (allconsuming, amazon.co.uk). And the story is probably originally from the Chuang Tzu text (or Zhuang-zi), which was compiled during the Tan Dynasty, 202BCE-220AD.