The following paragraphs are from an essay about the construction of the Eddystone Lighthouse and the development of modern cement. To make the essay most logical and cohesive, in what order should the paragraphs be arranged?
- 1For centuries, the Eddystone Rocks—a treacherous group of reef structures off the coast of Devon, England—posed a catastrophic hazard to mariners. The first two lighthouses erected on this reef were constructed primarily of wood. Predictably, the relentless force of Atlantic gales and waves destroyed both structures, demonstrating that timber was fundamentally inadequate to withstand the site's brutal marine environment.
- 2When civil engineer John Smeaton was tasked with designing a third lighthouse in 1756, he recognized that he needed a material far sturdier than wood: stone. However, bonding heavy granite blocks together on a wave-swept reef presented a critical obstacle. Smeaton knew that traditional lime mortar required air to dry and would wash away long before it could set in the turbulent surf.
- 3To overcome this barrier, Smeaton embarked on a series of rigorous experiments, testing various mixtures of lime and clay. He discovered that lime containing a high proportion of clay, when mixed with pozzolanic volcanic ash, would set chemically even when completely submerged in water. This breakthrough led to the development of hydraulic lime, the first modern water-resistant cement.
- 4Armed with this revolutionary binding agent, Smeaton completed his stone tower in 1759, and it stood successfully for over a century. More importantly, Smeaton's formulation of hydraulic mortar laid the physical and chemical foundation for the reinvention of concrete, transforming global civil engineering and enabling the construction of modern ports, bridges, and tunnels.
Cevap
The paragraphs must be arranged in the sequence starting with the historical failures of wooden structures on the reef, followed by John Smeaton's transition to stone and the mortar issue, then the chemical experiments resulting in hydraulic lime, and ending with the completion of the lighthouse and the global legacy of modern cement.
The correct sequence flows from the historical background of the reef's hazards and early wooden failures, to John Smeaton's decision to use stone and his discovery of the mortar problem, to his subsequent experimental research creating hydraulic lime, and finally to the physical construction of the tower and its long-term impact on modern civil engineering.
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