physics

Otis King

Otis King is a physics 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 Otis King rather than just read about it. In short: Otis Carter Formby King (1876–1944) was an electrical engineer in London who invented and produced a cylindrical slide rule with helical scales, primarily for business uses initially. The product was named Otis King's Patent Calculator, and was manufactured and sold by Carbic Ltd. in London from about 1922 to about 1972.

Key takeaways

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

Reference excerpt

Otis Carter Formby King (1876–1944) was an electrical engineer in London who invented and produced a cylindrical slide rule with helical scales, primarily for business uses initially. The product was named Otis King's Patent Calculator, and was manufactured and sold by Carbic Ltd. in London from about 1922 to about 1972. With a log-scale decade length of 66 inches, the Otis King calculator should be about a full digit more accurate than a 6-inch pocket slide rule. But due to inaccuracies in tic-mark placement, some portions of its scales will read off by more than they should. For example, a reading of 4.630 might represent an answer of 4.632, or almost one part in 2000 error, when it should be accurate to one part in 6000 (66"/6000 = 0.011" estimated interpolation accuracy). The Geniac brand cylindrical slide rule sold by Oliver Garfield Company in New York was initially a relabelled Otis King; Garfield later made his own, probably unauthorized version of the Otis King (around 1959). The UK patents covering the mechanical device(s) would have expired in about 1941–1942 (i.e. 20 years after filing of the patent) but copyright in the drawings – which would arguably include the spiral scale layout – would typically only expire 70 years after the author's death.

Patents UK patent GB 207,762 (1922) [1] UK patent GB 183,723 (1921) [2] UK patent GB 207,856 (1922) [3] US patent US 1,645,009 (1923) [4] Canadian patent CA 241986 [5] Canadian patent CA 241076 [6] French patent FR569985 [7] French patent FR576616 [8] German patent DE 418814 [9]

See also Bygrave slide rule Fuller's cylindrical slide rule

External links Dick Lyon's Otis King pages Cylindrical rules at Museum of HP Calculators

References

Worked examples

Example 1 — a first encounter with Otis King

Start with the simplest possible case. Write down what Otis King claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, 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 Otis King 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 Otis King 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 Otis King

In research: Otis King appears in physics 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 Otis King 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: Otis King is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1876 births, 1944 deaths, Analog computers, so understanding it makes those chapters shorter.
In everyday life: Look for Otis King 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.

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How to study Otis King in 20 minutes

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

Frequently asked questions

What is Otis King in simple terms?

Why does Otis King matter?

Because it connects several physics 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 Otis King?

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 Otis King.