engineering

Mostert's Mill

Mostert's Mill is a engineering 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 Mostert's Mill rather than just read about it. In short: Mostert's Mill (Afrikaans: Mostert se Meul) is a historic windmill in Mowbray, Cape Town, South Africa. It was built in 1796 and is the oldest surviving complete windmill in South Africa.

Key takeaways

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

Reference excerpt

Mostert's Mill (Afrikaans: Mostert se Meul) is a historic windmill in Mowbray, Cape Town, South Africa. It was built in 1796 and is the oldest surviving complete windmill in South Africa. It was almost completely destroyed by a wildfire on 18 April 2021 but was fully restored by April 2024 and is once more operational and used to grind wheat into whole meal, using the power of the wind. The oldest windmill in South Africa is the De Nieuwe Molen mill in Cape Town, built in 1782.

History The mill was built around 1796 as a private mill on the farm 'Welgelegen', owned by Gysbert van Renen and was named after his son-in-law, Sybrand Mostert, after Van Renen's death. It was the first privately owned mill in Cape Town, Cape Colony. Prior to the British occupation of the Cape in the Battle of Muizenberg in 1795, only mills controlled by the Dutch East India Company were allowed. Mostert's Mill had ceased working by 1873 but was owned by the Mostert family until 1889, when it was sold to a Mr Wilks, who sold it in 1891 to Cecil Rhodes. The mill became derelict but a restoration was undertaken by the Dutch millwright Christiaan Bremer. The restored mill was opened on 1 February 1936 by Dr Lorentz, the Minister Plenipotentiary and Envoy Extraordinary to the Netherlands. The ceremony was attended by the Prime Minister, General Hertzog, and flour was ground for the guests. The mill was worked on occasion but it again became derelict during the Second World War. In 1986, the windshaft broke and the sails crashed to the ground. The Vernacular Architecture Society of South Africa started a campaign to preserve the mill, leading to the formation of the Friends of Mostert's Mill in 1993. A further restoration in 1995 by Dunning-Bremer (who restored the mill in 1935) returned the mill to working order again at a cost of R245,000. On 18 April 2021, the mill was gutted in a fire that had started on Table Mountain and destroyed several buildings, including one of the libraries of the University of Cape Town. The fire also destroyed four thatched houses behind the mill. At the time of the fire, Mostert's Mill was South Africa's oldest working mill. By March 2023, it was reported that the mill had been almost completely restored following the fire of April 2021. The restoration had been undertaken by the Friends of Mostert's Mill, a non-profit organisation.

Description

Mostert's Mill is a three-storey tower mill. The tower is 7.94 metres (26 ft 1 in) in diameter externally at ground level and 6.68 metres (21 ft 11 in) high. It was constructed of random stone for the first 2.28 metres (7 ft 6 in) and then unbaked bricks above. The walls are 1.15 metres (3 ft 9 in) thick at ground level, giving the mill an internal diameter of 5.64 metres (18 ft 6 in). Before the 2021 fire, the cap was of a truncated cone shape and covered by thatch. The mill had four common sails and was winded by a tailpole. The four, modern, common sails followed the Dutch tradition, as there was no surviving sail to copy when Bremer restored the mill in 1935. Those fitted at the 1935 restoration were 6.00 metres (19 ft 8 in) long and 1.75 metres (5 ft 9 in) wide, fitted with a windboard on the leading edge. Such a feature was not to be found on other South African windmills. The sails, which had a span of 14.45 metres (47 ft 5 in), were carried on a teak windshaft. This was fitted with a cast iron poll end in 1935, because the terminus of the wooden shaft had rotted. Contemporary South African windmills all had wooden windshafts, apart from one of the Salt River windmills, which had an iron cross. A replacement windshaft made of iroko was fitted in 1995. The windshaft carried a clasp arm brake wheel, which had a diameter of 770 millimetres (2 ft 6 in) and had 47 cogs. It drove the single pair of millstones, via a lantern pinion stone nut, which had 16 staves. The millstones comprised the original runner stone and a non-original bedstone. The latter was a Cullen stone installed in 1935 and came from a windmill at Leens, Groningen, Netherlands.

Location and access Mostert's Mill is situated on the M3 close to the University of Cape Town on the slopes of Devil's Peak where it was a prominent landmark. The Friends of Mostert's Mill operated the mill and it was open to the public on one Saturday a month between 10:00 and 14:30.

References

Sources Walton, James (1974). Water-mills windmills and horse mills of South Africa. Cape Town and Johannesburg: C Struik. ISBN 0-86977-040-3.

External links

Friends of Mostert's Mill News report with video of the burnt mill Detailed drawings of Mostert's mill

Illustrations

Worked examples

Example 1 — a first encounter with Mostert's Mill

Start with the simplest possible case. Write down what Mostert's Mill claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, 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 Mostert's Mill 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 Mostert's Mill 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 Mostert's Mill

In research: Mostert's Mill appears in engineering 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 Mostert's Mill 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: Mostert's Mill is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1796 establishments in Africa, 1796 in the Cape Colony, 18th-century architecture in South Africa, so understanding it makes those chapters shorter.
In everyday life: Look for Mostert's Mill 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 Mostert's Mill in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Mostert's Mill 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 Mostert's Mill out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Mostert's Mill in simple terms?

Mostert's Mill (Afrikaans: Mostert se Meul) is a historic windmill in Mowbray, Cape Town, South Africa. It was built in 1796 and is the oldest surviving complete windmill in South Africa.

Why does Mostert's Mill matter?

Because it connects several engineering 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 Mostert's Mill?

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 Mostert's Mill.