Protest in Palindrome
In his Remains Concerning Britain (1870), William Camden relates how a “scholar and a gentleman, living in a rude country town, where he had no respect, wrote this with a coal in the Town Hall:–Subi dura à rudibus.”
It means “endure rough treatment from uncultured brutes” — and it reads the same forward and backward.
Wait, What?
When the day after tomorrow is yesterday, today will be as far from Sunday as today was from Sunday when the day before yesterday was tomorrow. What day is it?
(Answer)
Jumbo Jet
Say what you will about the French, they know how to build an elephant:

This one, proposed for the Champs-Élysées in 1758, had air conditioning, a spiral staircase, and a drainage system in the trunk.
The French government said no. There’s no accounting for taste.
Easy
Write down any number:
886328712442992
Count up the number of even and odd digits, and the total number of digits:
10 5 15
String those together to make a new number, and perform the same operation on that:
10515
1 4 5
And keep iterating:
145
1 2 3
You’ll always arrive at 123.
See also Kaprekar’s Constant and The Pull of Four.
Small Security
What was the wonderful work of Mark Scalliot? Probably the smallest lock and key ever made. He was a London blacksmith, and this piece of mechanism (1578) was of iron, steel, and brass, all of which, with a pipe-key to it, weighed but one grain of gold. He also made a chain of gold, consisting of forty-three links, and having fastened the chain to the lock and key, he put the chain around the neck of a flea. The flea could hop around with ease in spite of the weight. The lock, key, chain and animal, all in a lump, weighed only one grain and a half.
– Albert Plympton Southwick, Handy Helps, No. 1, 1886
Celestial

Each book in Dante’s Divine Comedy ends with the word stars.
“Grammatical Puzzle”: Solution
Solution to Grammatical Puzzle:
“Take away L in the subjunctive ‘Let’ at the beginning of the first line, and substitute S, and so turn it into the imperative ‘Set,’ when the changes which necessarily follow will be immediately apparent”:
Set the rich, great, and noble banquet in the festal halls,
And pass the hours away, as the most thoughtless revel;
Then seek the poor man’s dreary home, whose very dingy walls
Proclaim full well to all how low his rank and level.
(As I read it, rich, great, and noble are now adjectives, banquet a noun, pass and seek second-person imperative verbs, thoughtless a noun, revel a verb, and all how low a noun phrase; away now means “apart,” rather than “freely,” and very is an adjective meaning “precisely.” The banquet is decadent, the home humble.)
From Dick & Fitzgerald, The Book of 500 Curious Puzzles, 1859.
In a Word
decumbiture
n. the act of going to bed when sick
Math Notes

“Grammatical Puzzle”
Let the rich, great, and noble banquet in the festal halls,
And pass the hours away, as the most thoughtless revel;
Then seek the poor man’s dreary home, whose very dingy walls
Proclaim full well to all how low his rank and level.
“Take away one letter from a word in the above stanza, and substitute another, leaving the word so metamorphosed still a word of the English language; and, by that change, totally alter the syntactical construction of the whole sentence, changing the moods and tenses of verbs, turning verbs into nouns, nouns into adjectives, and adjectives into adverbs, &c., and so make the entire stanza bear quite a different meaning from that which it has as it stands above.”
(Solution)
