ArticleslgStudy

science

Thirteenth stroke of the clock

Thirteenth stroke of the clock is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Thirteenth stroke of the clock rather than just read about it. In short: Thirteenth stroke of the clock or "thirteen strikes of the clock" is a phrase, saying, and proverb to indicate that the previous events or "strokes to the clock" must be called into question. This is illustrated in the fictional case of "Rex vs Haddock" in which a remark by one of the parties is compared to the thirteenth stroke of a clock: not only is this thirteenth strike itself discredited, but it casts a shade…

Thirteenth stroke of the clock — main illustration
Thirteenth stroke of the clock — illustration

Key takeaways

  • Thirteenth stroke of the clock belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Thirteenth stroke of the clock to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Thirteenth stroke of the clock from memory before moving on to harder problems.

Reference excerpt

Thirteenth stroke of the clock or "thirteen strikes of the clock" is a phrase, saying, and proverb to indicate that the previous events or "strokes to the clock" must be called into question. This is illustrated in the fictional case of "Rex vs Haddock" in which a remark by one of the parties is compared to the thirteenth stroke of a clock: not only is this thirteenth strike itself discredited, but it casts a shade of doubt over all previous assertions. This proverb puts forth the notion that if just one of someone's proclamations is wrong, or something of a process is wrong, then the correctness and accuracy of all the previous items are called into question. In a legal case it brings forth the notion that perhaps none of the party's claims are valid, given that one of them is obviously wrong. A physicist and mathematician notes the problem with his variation on the same general idea. He points out that if a clock strikes the thirteenth hour then it has counted wrongly and reflects on the other twelve hours of the clock's strokes as then they could also be wrong. Within the 24-hour clock system used for official and technical purposes throughout most of the world, there is a time that could be called "13 o'clock". However, the 24-hour system only came into widespread use in the English-speaking world during the 20th century, and most analogue clocks (including virtually all chiming or striking clocks) still work on the 12-hour system. A striking clock rings a bell once for each hour of the time. One ring is 1 o'clock, two rings is 2 o'clock, three rings is 3 o'clock, etc. Traditional clocks that strike a bell only mark 12 hours. After the twelfth hour with the twelve rings of the bell, the next hour should be with one ring only, indicating 1 o'clock plus twelve hours. Accordingly, with very rare exceptions, when a clock rings thirteen times it is indicating an impossible time and that the clock is not functioning correctly.

Striking clock mechanism

A 100-year-old tower striking clock has a striking mechanism, called a snail, with indentations that vary in depth progressively from one to twelve. It rotates via a gear drive over a twelve-hour period. Shortly before each hour a rack with twelve cuts along its length is released to contact the snail. This makes the number of cuts available to activate the strike mechanism correspond to the depth of the snail at that hour. Testing the rack in its place allows it to fall until the tail rests on the lowest step of the snail. The hook of the rack should then hold the rack so that there are twelve teeth gathered up. Trying it on the highest step of the snail, should catch the first rack tooth. This leaves only one to be gathered up. If the clock strikes thirteen when on the lowest step and two when on the highest, it shows that the end of the rack tail is a little too far off from the snail and must be set a little closer. If on the other hand the snail strikes the right number when on the lowest step and two when on the highest, then the proportion between the snail and rack is wrong. The rack travel is too great for the rack.

Culture

There is an 18th-century London legend of a clock that struck thirteen times and saved a man's life. The story goes that St Paul's Cathedral clock on one occasion struck thirteen bongs of the bell at midnight, with the result of saving the life of a soldier accused of sleeping at his post. An obituary notice of a John Hatfield that appeared in the Public Advertiser a few days after his death states that as a soldier in the time of William III and Mary II he was tried by a court-martial on a charge of having fallen asleep when on duty upon the terrace at Windsor. It goes on to say that he categorically denied the charge against him. He swore as a proof of his having been awake at the time that he heard St Paul's Cathedral clock strike thirteen, the truth of which was much doubted by the court because of the great distance. Affidavits were made by several persons verifying that the clock actually did strike thirteen instead of twelve, and the soldier was pardoned. There is a poem that alludes to this published in July 1873 called A Trip to Windsor by Timothy Scribble:

The terrace walk we with surprise behold,Of which the guides have oft the story told:Hatfield, accused of sleeping on his post,Heard Paul's bell sounding, or his life had lost. Adolf Hitler is quoted as saying, "I make it a principle not to stop until the clock strikes thirteen". This was in reference to his never giving up as Germany did in the First World War. This was said in November 1942 as the defeat of the German army at Stalingrad became certain, and the German army had retreated in North Africa. He wanted to point out to his enemy that he was not going to surrender under any circumstances, by using an analogy that theoretically could not happen. Francis Egerton, 3rd Duke of Bridgewater, owned extensive coal mines near Manchester. He spent a fortune operating them and building a canal to carry the coal to Manchester and Liverpool. He noticed that his workers ceased working the moment the bell struck twelve times at twelve o'clock, which was lunch time. They, however, were slow in returning to work at one o'clock. The excuse was that they did not hear the clock strike just once. The Duke then had the clock made to strike thirteen times at one o'clock, so that the men could no longer use the excuse that they did not hear it. Mark Twain is claimed to have said: "The thirteenth stroke of the clock is not only false of itself, but casts grave doubt on the credibility of the preceding twelve".

Literature The idea of a clock striking thirteen times has shown up many times in literature. The most famous is the first line in George Orwell's Nineteen Eighty-Four when it starts with, "It was a bright cold day in April, and the clocks were striking thirteen". The famous children's book Tom's Midnight Garden by Philippa Pearce speaks of this phenomenon when it says "When Tom hears old Mrs Bartholomew's grandfather clock in the hall striking thirteen, he goes to investigate". Thomas Hardy wrote in Far from the Madding Crowd (1872): "This supreme instance of Troy's goodness fell upon Gabriel's ears like the thirteenth stroke of a crazy clock." (Chapter XXIX, Particulars of a twilight walk.)

… excerpt ends here. Continue reading the full article.

Illustrations

Thirteenth stroke of the clock: St Paul's Cathedral SW tower clock in London; the River Thames can be seen at left.
St Paul's Cathedral SW tower clock in London; the River Thames can be seen at left.

Worked examples

Example 1 — a first encounter with Thirteenth stroke of the clock

Start with the simplest possible case. Write down what Thirteenth stroke of the clock claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Thirteenth stroke of the clock before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Thirteenth stroke of the clock ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Thirteenth stroke of the clock

In research
Thirteenth stroke of the clock appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Thirteenth stroke of the clock in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Thirteenth stroke of the clock is common in secondary-school and first-year university syllabi. It links to neighbouring topics Clocks, Phrases, so understanding it makes those chapters shorter.
In everyday life
Look for Thirteenth stroke of the clock outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Thirteenth stroke of the clock” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Thirteenth stroke of the clock in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Thirteenth stroke of the clock means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Thirteenth stroke of the clock out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Thirteenth stroke of the clock in simple terms?

Thirteenth stroke of the clock or "thirteen strikes of the clock" is a phrase, saying, and proverb to indicate that the previous events or "strokes to the clock" must be called into question. This is illustrated in the fictional case of "Rex vs Haddock" in which a remark by one of the parties is co…

Why does Thirteenth stroke of the clock matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Thirteenth stroke of the clock?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Thirteenth stroke of the clock.

Tags

  • Clocks
  • Phrases

Keep exploring