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Thomas Grubb

Thomas Grubb 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 Thomas Grubb rather than just read about it. In short: Thomas Grubb (4 August 1800 – 16 September 1878) was an Irish optician, astronomer, engineer, early photographer, and founder of the Grubb Telescope Company. Early life He was born near Portlaw, County Waterford, Ireland, the son of William Grubb Junior, a prosperous Quaker farmer and his second wife, Eleanor Fayle.

Thomas Grubb — main illustration
Thomas Grubb — illustration

Key takeaways

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

Reference excerpt

Thomas Grubb (4 August 1800 – 16 September 1878) was an Irish optician, astronomer, engineer, early photographer, and founder of the Grubb Telescope Company.

Early life He was born near Portlaw, County Waterford, Ireland, the son of William Grubb Junior, a prosperous Quaker farmer and his second wife, Eleanor Fayle. Thomas started out in 1830 in Dublin as a metal billiard-table manufacturer. He diversified into making telescopes and erected a public observatory near his factory at 1 Upper Charlemont Street, Portobello, Dublin. As makers of some of the largest and best-known telescopes of the Victorian era, the company was at the forefront of optical and mechanical engineering. His innovations for large telescopes included clock-driven polar mounts, whiffletree mirror mounting cells and Cassegrain reflector optics. Later, the manufacturing firm changed its name to Grubb-Parsons in 1925.

Works Thomas Grubb's reputation as a competent telescope maker began to spread as he offered his talents to the Irish astronomical community. Grubb first met the director of Armagh Observatory, Romney Robinson, sometime in the 1830s. His first commission was for E.J. Cooper of Markree Observatory. He was tasked to mount a 13.3 inch lens which was used to view the solar eclipse of 15 May 1836. Grubb helped build the famous telescope for William Parsons, 3rd Earl of Rosse, at Parsonstown (now known as Birr), County Offaly, Ireland. One of his earliest instruments - the telescope for Markree Observatory in County Sligo in the West of Ireland, supplied in 1834 - was, until 1839, the largest refracting telescope in the world. It was used to sketch Halley's comet in 1835 and to view the solar eclipse of 15 May 1836. Grubb's work at the Markree Observatory would become known as a milestone in the creation and handling of large-scale telescopes. In 1837, Thomas Grubb worked with fellow Irish scientist James MacCullagh. Together, they conducted a series of experiments on metallic refraction. Later he built telescopes for observatories worldwide, including Aldershot Observatory, Melbourne, Vienna, Madrid and Mecca and others. Thomas Grubb's company also made various scientific devices for Trinity College in Dublin. In 1839, his company made about twenty sets of magnetometers. These magnetometers were requested by Professor Humphrey Lloyd who was very involved with Grubb's work. He sought Grubb's talents because so he could be close to the creation process and supervise his work. Starting from 1840, Grubb also worked as an engineer for the Bank of Ireland. He was responsible for designing machines used in the creation of banknotes. These machines were used for engraving, printing and numbering the banknotes. Grubb made a contract with the government of Ireland in 1866 to construct a telescope that would be sent to the southern hemisphere for use to compare the sky from there. This project would be known as the construction of the Melbourne Telescope. Grubb was tasked with mounting the telescope. He provided a large support to provide stability. The Royal Society Committee would go on to describe the telescope as 'a masterpiece of engineering'. This project would become renown amongst the global astronomers community and bolster Grubb's reputation. Unfortunately, the project would end in failure when the telescope was actually dismantled and shipped to Australia. Grubb was tasked of constructing a Cassegrain reflector that would include two 4-foot metal mirrors. The problem with the project was Grubb's choice of metal. This caused defects in the form of the astronomers in Melbourne being unable to re-polish the mirrors adequately. The last major work of Thomas Grubb's would start with him and end with his son Howard Grubb. In 1875, he would go on to build the Great Vienna Telescope. This would be known as the largest refracting telescope in the world up to that point.

Grubb Telescope Company

Thomas Grubb would begin his professional career in Dublin, Ireland in the year 1830 as a mechanical engineer. Here he would create telescopes that became infamous within the Irish astronomical community. His company would be officially be passed on to his son Thomas Grubb in 1916. What started as a general manufacturing firm would be formally renamed Grubb-Parsons by Sir Charles Parsons in 1925. The firm was instrumental to the war efforts in World War I and would change its focus from telescope making to aiding the allies in their war efforts. This would include the creation of gun-sights and submarine periscopes. The escalation of the war – particularly in 1916 – caused the firm to be under military guard. In 1918, the factory would be moved to St. Albans, England in fear that Grubb-Parsons would be vulnerable in the weaker Ireland. This shift of focus from the company from telescopes to the war effort marked a decrease in economic power that Irish astronomers held over the industry. A global shift to provide for the United States and the allies would change the scope of Grubb-Parsons forever. It is noted that during the war, Grubb-Parsons built around 95% of the periscopes in British submarines.

Later life Thomas died in 1878 in Monkstown, Dublin, Ireland. He is buried at Mount Jerome Cemetery, Dublin, Ireland. Although the source of his death is unknown, he had been suffering from rheumatism since the start of the 1870s. He had married Sarah Palmer. Their youngest son was Sir Howard Grubb, who took over the optical business. Thomas Grubb's cousin, John Grubb Richardson (1813 - 1891) was a major Irish industrialist who founded the model village of Bessbrook.

References

External links

Works by or about Thomas Grubb at the Internet Archive Grubb Telescope Company List of Grubb telescopes [1]

Illustrations

Thomas Grubb illustration
Thomas Grubb: Site of his first Engineering Works & Observatory
Site of his first Engineering Works & Observatory

Worked examples

Example 1 — a first encounter with Thomas Grubb

Start with the simplest possible case. Write down what Thomas Grubb 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 Thomas Grubb 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 Thomas Grubb 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 Thomas Grubb

In research
Thomas Grubb 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 Thomas Grubb 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
Thomas Grubb is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1800 births, 1878 deaths, 19th-century Irish astronomers, so understanding it makes those chapters shorter.
In everyday life
Look for Thomas Grubb 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 Thomas Grubb in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Thomas Grubb 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 Thomas Grubb out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Thomas Grubb in simple terms?

Thomas Grubb (4 August 1800 – 16 September 1878) was an Irish optician, astronomer, engineer, early photographer, and founder of the Grubb Telescope Company. Early life He was born near Portlaw, County Waterford, Ireland, the son of William Grubb Junior, a prosperous Quaker farmer and his second wi…

Why does Thomas Grubb 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 Thomas Grubb?

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 Thomas Grubb.

Tags

  • 1800 births
  • 1878 deaths
  • 19th-century Irish astronomers
  • 19th-century Irish male photographers
  • 19th-century Irish photographers
  • Burials at Mount Jerome Cemetery and Crematorium
  • Irish fellows of the Royal Society
  • Irish inventors
  • Lens designers
  • People from County Waterford
  • Telescope manufacturers

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