The year dot

Meaning

A very long time ago; too long ago to be dated.


Original

This is a fairly recent phrase which originated in England at the end of the 19th century. It is still in use there, although less so elsewhere. The earliest record I can find of it in print is from the English author William Pett Ridge's Minor Dialogues, 1895:

"I reckon he was born in the year dot, that 'orse was."

The Yellow Peril

Meaning

The supposed danger of Oriental hordes overwhelming the West.
Origin
The phrase 'The Yellow Peril' is no longer used in anger, so to speak. The threat of Oriental hordes swarming west and engulfing 'civilised' societies was a widely held fear in the late 19th/early 20th centuries.
A pre-cursor to the yellow peril was the yellow terror. This was initially used to denote the deadly Yellow Fever - also sometime known as American Plague. An outbreak of the disease was reported in October 1878 by the Iowa newspaper The Dubuque Herald Iowa:
The Yellow Terror - The list of new cases does not diminish.
Just a few years later, in October 1894, the Wisconsin Daily Gazette used the term to describe a Chinese general, whom it likened to both Wellington and Napoleon. They helpfully provided a sketch of the 'inscrutable' commander:
THE YELLOW TERROR OF ORIENTAL WARS - GEN. YEH OF THE IMPERIAL CHINESE ARMY.
He Is the Wellington of the Flowery Kingdom - His Field Tactics, However, Resemble Those of the Corsican Conqueror of Europe, and Ought To Be Successful.
The yellow was clearly an allusion to skin colour, although not to the cowardice suggested by the American term yellow bellied, which was coined later.
The fear in the West of the mysterious, and many believed unknowable, Orientals was as real at the turn of the 20th century as the fear of Muslims at the start of the 21st, and just as misguided.
The term Yellow Peril was coined following Japan's military defeat of China in 1895 and was generally applied to Japan. It has been reported as being coined by the German Kaiser Wilhelm II, in September 1895. If the Kaiser did coin the phrase then the date is incorrect as the term was used earlier that year by the Hungarian General Turr, in an assessment of Bismark. This was reported in several US newspaper at the time, including the Ohio paper The Sandusky Register, June 1895:
"The 'yellow peril' is more threatening than ever. Japan has made in a few years as much progress as other nations have made in centuries."
It is true that the Kaiser was virulently anti-Japanese/Chinese and he commissioned a painting which was intended to encourage Europeans to cooperate to beat back the Eastern menace. The painting, which was made into a widely used poster, shows a distant Buddha-like figure (not unlike General Yeh) sitting in an approaching firestorm while an Ayran messenger warns the womenfolk of various countries of their impending doom.
The fear of invasion continued into the 20th century and was bolstered by various portrayals of sinister Orientals in books and films. Prominent amongst these was the English writer Sax Rohmer's creation, the insidious and diabolical genius Dr. Fu Manchu. By the outbreak of WWI, the lack of any actual invasion and the fact that the Kaiser and his ilk had by then better things to think about, talk of the Yellow Peril began to fade.

A shot across the bows

Meaning

A warning shot, either real or metaphorical.
Origin
That most useful reference, Admiral William Smyth's The sailor's word-book: an alphabetical digest of nautical terms, 1865, defines the bows thus:
"The fore-end of a ship or boat; being the rounding part of a vessel forward, beginning on both sides where the planks arch inwards, and terminating where they close, at the rabbet of the stem or prow, being larboard or starboard from that division".
Land-lubbers might find it easier to imagine bows as the 'shoulders' of a boat or ship. And if you don't know the difference between a boat and a ship there's also a land-lubbers guide to that - 'you can get a boat on a ship, but you can't get a ship on a boat'.
'A shot across the bows' derives from the naval practice of firing a cannon shot across the bows of an opponent's ship to show them that you are prepared to do battle. The first mention of it I can find in print is this piece from the Wisconsin Democrat, December 1939, reprinted from the UK paper The London Metropolitan:
"In a very brief space we neared our victim, a large merchantman, whose appearance promised at once an easy conquest and a rich booty. At a signal from Stamar, a shot was fired across her bows to bring her to. She immediately hoisted a white flag."
The more general figurative use of the expression, just to mean warning, is a 20th century innovation. For example, this piece from The Fresno Bee Republican, just prior to WWII, in August 1937:
"When the situation In Central Europe becomes threatening in the eyes of the great public, when press and official telegrams point to an immediate danger, the United States government will fire the third warning shot across the bows."