astronomy

Secretan (company)

Secretan (company) is a astronomy 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 Secretan (company) rather than just read about it. In short: Secretan was a company based in Paris, France that manufactured telescopes and other scientific instruments. History In 1845, Marc Secretan (1804–1867), a Swiss mathematician, and Noël Paymal Lerebours (1807–1873), a French optician, established a firm in Paris that manufactured precision instruments.

Key takeaways

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

Reference excerpt

Secretan was a company based in Paris, France that manufactured telescopes and other scientific instruments.

History In 1845, Marc Secretan (1804–1867), a Swiss mathematician, and Noël Paymal Lerebours (1807–1873), a French optician, established a firm in Paris that manufactured precision instruments. In 1854, Secretan became the sole owner of the company, which continued to operate under the name Lerebours & Secretan. With popular interest in astronomy growing, the French physicist Léon Foucault (1819–1868) entered into an exclusive contract with Secretan for the commercialization of a reflecting telescope. Upon the death of Secretan in 1867, the company’s management first passed to his son Auguste François (1833–1874), and then to Auguste’s cousin Georges Emmanuel Secrétan (1837–1906). Around 1889, Georges Secrétan moved the company’s workshops to 30 rue du Faubourg Saint-Jacques, near the Paris Observatory and appointed Raymond Augustin Mailhat (1862 – 1923) as their head from 1 January 1889. In 1894, Mailhat bought some of the workshops and set up his own business, while Secretan moved his equipment into a new location at 41, quai de l’Horloge, near to the company’s retail shop on the Place du Pont-Neuf. When Georges Secrétan died in 1906, his son Paul Victor (b. 1879) and daughter Alice (b. 1878) inherited the business, which they ran until 1911, when they sold it to Charles Épry. In 1913, Gustave Jacquelin (1879–1939) became Épry’s associate and the firm continued manufacturing and selling astronomical, scientific and optical products. In 1963, the Secretan company merged with the Henri Morin company, a producer of surveying and drawing equipment, and was renamed as the Etablissements H. Morin-Secretan. Around 1967, that firm merged with the Société de Recherches et de Perfectionnements Industriels (SRPI), which operated until at least 1981.

Illustrations

Worked examples

Example 1 — a first encounter with Secretan (company)

Start with the simplest possible case. Write down what Secretan (company) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, 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 Secretan (company) 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 Secretan (company) 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 Secretan (company)

In research: Secretan (company) appears in astronomy 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 Secretan (company) 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: Secretan (company) is common in secondary-school and first-year university syllabi. It links to neighbouring topics French companies established in 1845, Telescope manufacturers, so understanding it makes those chapters shorter.
In everyday life: Look for Secretan (company) 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 Secretan (company) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Secretan (company) 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 Secretan (company) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Secretan (company) in simple terms?

Secretan was a company based in Paris, France that manufactured telescopes and other scientific instruments. History In 1845, Marc Secretan (1804–1867), a Swiss mathematician, and Noël Paymal Lerebours (1807–1873), a French optician, established a firm in Paris that manufactured precision instrumen…

Why does Secretan (company) matter?

Because it connects several astronomy 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 Secretan (company)?

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 Secretan (company).