astronomy

John Bird (astronomer)

John Bird (astronomer) 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 John Bird (astronomer) rather than just read about it. In short: John Bird (1709– 31 March 1776) was a British mathematical instrument maker with an interest in astronomy who was notable for making high quality mural quadrants, octants, and sextants. Nevil Maskelyne used sextants made by Bird that had telescopes specially made by John Dollond and his son Peter.

Key takeaways

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

Reference excerpt

John Bird (1709– 31 March 1776) was a British mathematical instrument maker with an interest in astronomy who was notable for making high quality mural quadrants, octants, and sextants. Nevil Maskelyne used sextants made by Bird that had telescopes specially made by John Dollond and his son Peter.

Life and work

Bird was born in Bishop Auckland, County Durham and initially worked as a weaver. He became interested in the marking of divisions on clock dials and began to experiment on it and developed the skills. He became a friend of the mathematician William Emerson and he was able to recommend Jeremiah Dixon as a choice for the Woolwich Academy to send to St. Helena to study the transit of Venus. He came to London in 1740 where he worked for Jonathan Sisson (and his son Jeremiah) and later George Graham. By 1745, he had his own business was at the sign of Sea Quadrant, Court Garden, in the Strand. Bird was commissioned to make a brass quadrant 8 feet across for the Royal Observatory at Greenwich, where it was mounted on 16 February 1750, and where it is still preserved. Soon after, duplicates were ordered for France, Spain and Russia. The quadrant was considered to be of great quality as three years later it was off by just 0.5 minutes of the degree despite the temperature effects on metals. In 1764 Bliss and Bird made measurements of the diameter of the moon using a 2-foot reflecting telescope. Thomas Hornsby hired Bird to make instruments for the Radcliffe Observatory, Oxford, and his Equatorial Sector is one of the few that still exists. Along with Captain John Campbell, he designed portable sextants for use at sea. Bird supplied the astronomer James Bradley with further instruments of such quality that the commissioners of longitude paid him £500 (a huge sum) on condition that he take on an apprentice for 7 years and produce in writing upon oath, a full account of his working methods. This was the origin of Bird's two treatises The Method of Dividing Mathematical Instruments (1767) and The Method of Constructing Mural Quadrants (1768). Both had a foreword from the astronomer-royal Nevil Maskelyne. When the Houses of Parliament burned down in 1834, the standard yards of 1758 and 1760, both constructed by Bird, were destroyed. Bird, with his fellow County Durham savant William Emerson, makes an appearance in Mason & Dixon, the acclaimed novel by Thomas Pynchon.

References

Further reading Bedini, Silvio (1970–1980). "Bird, John". Dictionary of Scientific Biography. Vol. 2. New York: Charles Scribner's Sons. pp. 140–141. ISBN 978-0-684-10114-9.

External links Biography on South Seas Companion Mural quadrants

Illustrations

Worked examples

Example 1 — a first encounter with John Bird (astronomer)

Start with the simplest possible case. Write down what John Bird (astronomer) 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 John Bird (astronomer) 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 John Bird (astronomer) 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 John Bird (astronomer)

In research: John Bird (astronomer) 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 John Bird (astronomer) 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: John Bird (astronomer) is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1709 births, 1776 deaths, 18th-century British astronomers, so understanding it makes those chapters shorter.
In everyday life: Look for John Bird (astronomer) 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 John Bird (astronomer) in 20 minutes

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

Frequently asked questions

What is John Bird (astronomer) in simple terms?

Why does John Bird (astronomer) 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 John Bird (astronomer)?

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 John Bird (astronomer).