engineering

Portland Head Light

Portland Head Light 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 Portland Head Light rather than just read about it. In short: Portland Head Light is a historic lighthouse in Cape Elizabeth, Maine. The light station sits on a headland at the entrance of the primary shipping channel into Portland Harbor, which is within Casco Bay in the Gulf of Maine.

Key takeaways

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

Reference excerpt

Portland Head Light is a historic lighthouse in Cape Elizabeth, Maine. The light station sits on a headland at the entrance of the primary shipping channel into Portland Harbor, which is within Casco Bay in the Gulf of Maine. Completed in 1791, it was the first lighthouse built by the U.S. government and is the oldest lighthouse in Maine. The light station is automated, and the tower, beacon, and foghorn are maintained by the United States Coast Guard, while the former lighthouse keeper's house is a maritime museum within Fort Williams Park.

History In 1785, leaders in historic Falmouth directed their representative to the Massachusetts General Court to secure funding for construction of a lighthouse at Portland Head. Construction began in 1787 at the directive of George Washington and was completed on January 10, 1791, using a fund of $1,500, established by him. Whale oil lamps were originally used for illumination. In 1855, following the formation of the Lighthouse Board, a fourth-order Fresnel lens was installed; that lens was replaced by a second-order Fresnel lens, which was replaced later by an aerobeacon in 1958. That lens was replaced with a DCB-224 aerobeacon in 1991. The DCB-224 aerobeacon is still in use.

In 1787, while Maine was still part of the state of Massachusetts, George Washington engaged two masons from the town of Falmouth (modern-day Portland), Jonathan Bryant and John Nichols, and instructed them to take charge of the construction of a lighthouse on Portland Head. Washington reminded them that the early government was poor, and said that the materials used to build the lighthouse should be taken from the fields and shores, materials which could be handled nicely when hauled by oxen on a drag. The original plans called for the tower to be 58 feet tall. When the masons completed this task, they climbed to the top of the tower and realized that it would not be visible beyond the headlands to the south, so it was raised another 20 feet. The tower was built of rubblestone, and Washington gave the masons four years to build it. While it was under construction in 1789, the federal government was being formed, and for a while, it looked as though the lighthouse would not be finished. Following passage of their ninth law, the first congress made an appropriation and authorized the Secretary of the Treasury, Alexander Hamilton, to inform the mechanics that they could go on with the completion of the tower. On August 10, 1790, the second session of Congress appropriated a sum not to exceed $1500, and under the direction of the President, "to cause the said lighthouse to be finished and completed accordingly." The tower was completed in 1790 and first lit on January 10, 1791. During the American Civil War, raids on shipping in and out of Portland Harbor became commonplace, and because of the necessity for ships at sea to sight Portland Head Light as soon as possible, the tower was raised 20 more feet. The current keepers' house was built in 1891. When Halfway Rock Light was built, Portland Head Light was considered less important, and in 1883, the tower was shortened 20 feet (6.1 m) and a weaker fourth-order Fresnel lens was added. Following the mariners' complaints, the former height and second-order Fresnel lens were restored in 1885. In 1886, the barque Annie C. Maguire went aground at Portland Head Light, with the crew and passengers able to get ashore. The station has changed little except for rebuilding the whistle house in 1975 due to its having been badly damaged in a storm; and switching to automated operations in August 1989. Davis Simpson was the last to hold the role head light keeper with Nathan Wasserstrom assistant light keeper. Wasserstrom's spouse recollected hearing of the opportunity to live at Portland Head Light while renting a small apartment, saying "when I came out here and saw how beautiful it was, I thought to myself that we’d never have another chance to live in a wonderful place like this.” Today, Portland Head Light stands 80 feet (24 m) above ground and 101 feet (31 m) above water, its white conical tower is connected to a dwelling. The grounds and historic keeper's house are owned by the town of Cape Elizabeth, while the beacon and fog signal is owned and maintained by the U.S. Coast Guard as a current aid to navigation. It was added to the National Register of Historic Places as Portland Head light (sic) on April 24, 1973, reference number 73000121. The lighthouse was designated as a National Historic Civil Engineering Landmark by the American Society of Civil Engineers in 2002.

In art and popular culture Edward Hopper painted the lighthouse in 1927. His watercolor resides at Boston's Museum of Fine Arts. A snowy Portland Head Light was featured in the 1999 drama Snow Falling on Cedars, which was filmed during the Ice storm of 1998. The lighthouse was featured in the fifth, sixth, and seventh seasons of Agents of S.H.I.E.L.D.. Described as being on the shores of Lake Ontario in the show, the building housed an underground facility used by S.H.I.E.L.D. as their covert base of operations. The lighthouse and its nearby shores are featured in the Disney attraction Soarin' Around America, found at Epcot in Walt Disney World. It was also featured on a postcard in the opening credits of National Lampoon's Vacation.

See also Annie C. Maguire shipwreck Port of Portland National Register of Historic Places listings in Cumberland County, Maine

References

External links Media related to Portland Head Lighthouse at Wikimedia Commons

Portland Head Light - official site Portland Head Light - United States Lighthouses

Illustrations

Worked examples

Example 1 — a first encounter with Portland Head Light

Start with the simplest possible case. Write down what Portland Head Light 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 Portland Head Light 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 Portland Head Light 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 Portland Head Light

In research: Portland Head Light 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 Portland Head Light 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: Portland Head Light is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1791 establishments in Maine, Cape Elizabeth, Maine, Historic Civil Engineering Landmarks, so understanding it makes those chapters shorter.
In everyday life: Look for Portland Head Light 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 Portland Head Light in 20 minutes

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

Frequently asked questions

What is Portland Head Light in simple terms?

Why does Portland Head Light 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 Portland Head Light?

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 Portland Head Light.