(Thanks, Macari.)

On a certain familiar island, some residents always lie, and the others always tell the truth. The total population is 100. Each resident worships one of three gods, the sun god, the moon god, or the Earth god. One day a visitor asks each resident three questions:

1. Do you worship the sun god?
2. Do you worship the moon god?
3. Do you worship the Earth god?

Sixty residents answer yes to the first question, 40 to the second, and 30 to the third. How many residents are liars?

(Apparently apocryphal, but entertaining.)

Like its predecessor, our present civilization may be no more than one of those crops farmers sow to improve their land by the fixation of nitrogen from the air; it may have grown only that, accumulating certain traditions, it may be ploughed into the soil again for better things to follow.

— H.G. Wells, The Outline of History, 1920

Through a remarkable series of blunders and ignorant reproductions of error, this word appears in modern dictionaries as ABACOT. In Hall’s Chron. a bicocket appears to have been misprinted abococket, which was copied by Grafton, altered by Holinshed to abococke, and finally ‘improved’ by Abraham Fleming to abacot (perhaps through an intermediate abacoc); hence it was again copied by Baker, inserted in his Glossarium by Spelman, and thence copied by Phillips, and so handed down through Bailey, Ash, Todd, etc., to 19th century dictionaries (some of which provide a picture of the ‘abacot’), and even inserted in dictionaries of English and foreign languages.

The OED defines abacot as a “variant of bycocket”.

An arresting sentence from poet George Barker’s 1950 novel The Dead Seagull:

“They cut down elms to build asylums for people driven mad by the cutting down of elms.”

How many distinct knots have exactly 10 crossings? By the late 20th century, mathematicians believed the number to be 166.

Then, in 1973, New York attorney and part-time mathematician Kenneth A. Perko Jr. discovered that two of these were essentially the same knot.

The correspondence had gone unnoticed for 75 years.

He explains everything (and answers the imagined objections above) in this essay.

“Flutterby’s grandfather died in 1872. Flutterby died one hundred and thirty-one years after his grandfather was born. Their ages add up to one hundred and five years. When was Flutterby born?”