The true test of happiness is whether you know what day of the week it is. A miserable man is aware of this even in his sleep. To be as cheerful and rosy-cheeked on Monday as on Saturday, and at breakfast as at dinner is to — well, make an ideal husband.

— W.N.P. Barbellion, The Journal of a Disappointed Man, 1919

There’s no blue circle here. The space among the lines is white. In the presence of black lines, the hue of a colored object seems to bleed into the surrounding background.

The phenomenon was first discovered in 1971. It’s known as neon color spreading.

In his 1940 essay “Boys’ Weeklies,” George Orwell writes, “The stories in the Magnet are signed ‘Frank Richards’ and those in the Gem, ‘Martin Clifford’, but a series lasting thirty years could hardly be the work of the same person every week.”

He was forced to add a footnote: “This is quite incorrect. These stories have been written throughout the whole period by ‘Frank Richards’ and ‘Martin Clifford’, who are one and the same person!”

This Alternative Heritage plaque adorns the house in Hull where John Venn was born in 1834.

In 1903, David Walsh, M.D., proposed building a national monument in Hyde Park so that the greatness of the British empire might be remembered in 8,000 years.

A square pyramid 150 feet high could enclose sculptures depicting British life and serve as a mausoleum for distinguished Britons. The cost might be defrayed by public subscription.

Asked his opinion, architect Aston Webb wrote, “It sounds to me too grand to have much chance of being carried through in this material age of ours, but I wish you all success.”

In losing chess, captures are obligatory, and the goal is to lose all one’s pieces or be stalemated. This makes it perilous from the start: Of White’s 20 legal opening moves, 13 allow Black to bait him successively through 16 consecutive captures, losing (and winning) the game by force. The example above shows what happens if White unwisely opens with 1. d3. If he’d started with 1. e3, he himself could have forced a win — if he knew all the correct lines.

Center Alley worse jester pore ladle gull hoe lift wetter stop-murder an toe heft-cisterns. Daze worming war furry wicket an shellfish parsons, spatially dole stop-murder, hoe dint lack Center Alley an, infect, word orphan traitor pore gull mar lichen ammonol dinner hormone bang. Oily inner moaning disk wicket oiled worming shorted, ‘Center Alley, gad otter bet, an goiter wark! Suture lacy ladle bomb! Shaker lake!’ an firm moaning tell gnat disk ratchet gull word heifer wark lacquer hearse toe kipper horsing ardor, washer heft-cistern’s closing, maker bets, gore tutor star fur perversions, cooker males, washer dashes an doe oily udder hoard wark. Nor wander pore Center Alley worse tarred an disgorged!

— Howard L. Chace, Anguish Languish, 1956

A segment of an image tends to seem larger when it’s filled with visual elements. This is true whether the elements are discrete or continuous.

Above, the right part of the top figure and the left part of the bottom figure each seems to fill more than half of its tier, though plainly these impressions can’t both be valid.

The illusion was first studied by German physicists Johann Joseph Oppel and August Kundt in the 1860s.

Born with an orthopedic condition that caused her knees to bend backward, Ella Harper made a virtue of necessity and joined W.H. Harris’s Nickel Plate Circus, where she took up a starring role and earned $200 a week ($7,200 today). Her pitch card reads:

I am called the camel girl because my knees turn backward. I can walk best on my hands and feet as you see me in the picture. I have traveled considerably in the show business for the past four years and now, this is 1886 and I intend to quit the show business and go to school and fit myself for another occupation.

She married a schoolteacher in 1905 and died in 1921 at 51.

The Vermin only teaze and pinch
Their Foes superior by an Inch.
So, Nat’ralists observe, a Flea
Hath smaller Fleas that on him prey,
And these have smaller yet to bite ’em,
And so proceed ad infinitum.

— Jonathan Swift

Great fleas have little fleas upon their backs to bite ’em,
And little fleas have lesser fleas, and so ad infinitum.
And the great fleas themselves, in turn, have greater fleas to go on;
While these again have greater still, and greater still, and so on.

— Augustus De Morgan