physics

Stuart Macrae (inventor)

Stuart Macrae (inventor) 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 Stuart Macrae (inventor) rather than just read about it. In short: Colonel Robert Stuart Macrae TD was an inventor best known for his work at MD1 during the Second World War, his best known invention being the sticky bomb. He is also known for the following.

Key takeaways

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

Reference excerpt

Colonel Robert Stuart Macrae TD was an inventor best known for his work at MD1 during the Second World War, his best known invention being the sticky bomb. He is also known for the following. Ministry of Defence 1 MD1 was located at "The Firs", Whitchurch. Also known as "Winston Churchill's Toyshop", this was a British weapon research and development organisation of the Second World War. Many of these inventions would be used by the SOE and Auxiliary Units. The two key figures were Major Millis Jefferis and Stuart Macrae. MD1 began in the "Military Intelligence Research" (MIR). The MIR was a department of the War Office set up in 1939 under Lt-Col Joe Holland, RE. Holland was the General Staff Officer Grade 1 (GSO1) and brought in Jefferis, also a sapper (RE) and explosives expert, as GSO2 to head MIR(c) a division of MIR that was to develop weapons for irregular warfare. Needing special magnets, Jefferis brought in Macrae initially as an outside contractor but later to be brought into uniform and serve as his deputy. MIR(c) started in a room at the War Office, Macrae secured offices and workshop space at IBC, owners of Radio Normandie, in London. Following an air raid, a large country house "The Firs", (fortunately the second home of a patriotic Major) was requisitioned and the design and workshops relocated there, in Whitchurch near Aylesbury in Buckinghamshire close to the Prime Minister at Chequers. There they developed and to some extent produced munitions. During the phoney war, MIR(c) was engaged in developing the floating mine required for Churchill's planned Operation Royal Marine which aimed to disrupt German shipping in their inland waterways by dropping these mines into the river at Strasbourg. Churchill lobbied for recognition of Jefferis, suggesting promotion. When MIR was combined with other activities to form the Special Operations Executive, MIR(C) instead in November 1940 became a department in the Ministry of Defence; effectively under the wing the Prime Minister, Churchill who was the Minister of Defence. As First Lord of the Treasury as well, Churchill could provide funds. Churchill, Professor Lindemann and General Ismay (Churchill's chief scientific and military advisors respectively) would protect MD1 from the Ministry of Supply and the Ordnance Board whose areas they encroached on. The Ministry of Supply carried out the administration but the War Cabinet was in control. Jefferis was promoted to Lt-Col and Macrae to Major. Other staff at MD1 included Stewart Blacker who was brought in after his privately invented Blacker Bombard was taken on for official development. With the end of the war and the removal of Churchill from office, MD1 was taken over by the Ministry of Supply and the Weapons research establishment at Fort Haldane with the result that it was disbanded. Macrae felt this was an act of revenge by those who had opposed it and the Professor. Production machinery went to the Rocket Propulsion Establishment at Westcott, effectively for scrapping. Jefferis received an appointment to the Pakistan Army.https://www.staybehinds.com/origins-md1-winston-churchills-toyshop Macrae was the author of Winston Churchill's Toyshop, a memoir detailing his experiences at MD1.

Early career Macrae had been a trainee engineer and late in the First World War worked on a device for dropping grenades as an early form of cluster bomb. The war ended before the device was used or he received any commission for his work. Macrae was an editor of Armchair Science magazine during the period leading up to the Second World War. He was approached by Millis Jefferis who was after strong magnets for a secret explosive project. Already security cleared from his previous work, Macrae was able to join in the project.

Second World War Macrae was called up as a second lieutenant on the Special List of the Territorial Army on 1 September 1939. with the effect that he had to give up editing Armchair Science and a gardening magazine at the same publisher. One of Macrae's first weapons inventions was a limpet mine. The mine was developed by Macrae and Cecil Vandepeer Clarke in 1939 using improvised development techniques. Macrae was the administrator of MD1, but also able to continue to be involved in developing weapons and devices. By the end of the war he was a war substantive lieutenant colonel. His promotion to full colonel, as a result of MD1 being upgraded to a Grade A Establishment, was halted by the end of the war. He remained in the TA after the war, transferring to the Royal Electrical and Mechanical Engineers (REME) as a substantive major on 9 October 1947 (with seniority from 6 October 1942).

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Stuart Macrae (inventor)

Start with the simplest possible case. Write down what Stuart Macrae (inventor) 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 Stuart Macrae (inventor) 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 Stuart Macrae (inventor) 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 Stuart Macrae (inventor)

In research: Stuart Macrae (inventor) 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 Stuart Macrae (inventor) 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: Stuart Macrae (inventor) is common in secondary-school and first-year university syllabi. It links to neighbouring topics British Army colonels, British Army personnel of World War II, English inventors, so understanding it makes those chapters shorter.
In everyday life: Look for Stuart Macrae (inventor) 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 Stuart Macrae (inventor) in 20 minutes

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

Frequently asked questions

What is Stuart Macrae (inventor) in simple terms?

Colonel Robert Stuart Macrae TD was an inventor best known for his work at MD1 during the Second World War, his best known invention being the sticky bomb. He is also known for the following.

Why does Stuart Macrae (inventor) 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 Stuart Macrae (inventor)?

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 Stuart Macrae (inventor).