Lighthouse Engineering

About Lighthouse Engineering

Give your memory a workout with Lighthouse Engineering: 15 multiple-choice questions with a mix of 6 medium, 5 easy, 4 hard questions, free to play right in your browser. Shine a light on your knowledge of lighthouse construction and maritime beacons! Expect to spend about 7 minutes; every question comes with an explanation, so you learn something even when you miss.

A few sample questions

1. 1. The Lighthouse of Alexandria (Pharos), one of the Seven Wonders of the Ancient World, was located in which country?

   Answer: Egypt

   The Lighthouse of Alexandria was built on the island of Pharos in Alexandria, Egypt, around 280 BC. Standing approximately 100-130 meters tall, it was one of the tallest structures in the ancient world and guided sailors for centuries.

2. 2. What revolutionary lens system, invented in 1822, dramatically improved the brightness and range of lighthouse beams?

   Answer: Fresnel lens

   The Fresnel lens, invented by French physicist Augustin-Jean Fresnel in 1822, uses concentric rings of prisms to concentrate light into a powerful beam. It could make a lighthouse visible from over 20 miles away.

3. 3. The Eddystone Lighthouse, located off the coast of Plymouth, England, was notable for being built on what?

   Answer: A dangerous reef in the open sea

   The Eddystone Lighthouse was built on the treacherous Eddystone Rocks, a reef 14 miles south of Plymouth. It has been rebuilt four times since 1698, with each version overcoming the extreme challenges of building on exposed rock in the open sea.

4. 4. What is the purpose of a lighthouse's unique flash pattern?

   Answer: To allow sailors to identify which lighthouse they are seeing

   Each lighthouse has a unique flash pattern (called its 'characteristic') so that sailors can identify exactly which lighthouse they are seeing. These patterns are published in nautical charts and 'Light Lists.'

5. 5. Which Scottish engineering family built over 100 lighthouses around Scotland's coast over several generations?

   Answer: The Stevensons

   The Stevenson family (including Robert, Alan, David, and Thomas Stevenson) designed and built over 100 lighthouses around Scotland's dangerous coastline over four generations. Robert Louis Stevenson, the famous author, was Thomas's son.

Things you'll learn along the way

• ✓Whale oil was the primary fuel for lighthouses in the 18th and early 19th centuries, later replaced by kerosene (paraffin oil) in the mid-1800s. Kerosene was cheaper, brighter, and more readily available than whale oil.
• ✓In 1999, the entire 4,830-ton Cape Hatteras Lighthouse was moved 2,900 feet (884 meters) inland to protect it from shoreline erosion. The move took 23 days and is one of the largest structures ever relocated.
• ✓John Smeaton developed a hydraulic lime cement for the third Eddystone Lighthouse that could set underwater. This early form of concrete was revolutionary and influenced the development of Portland cement and modern concrete.