TPO 30 Integrated Writing

Read the following passage and listen to a lecture before summerizing the important points in both passages.

Reading Passage

A little over 2200 years ago, the Roman navy attacked the Greek port city of Syracuse. According to some ancient historians, the Greeks defended themselves with an ingenious weapon called a 'burning mirror', a polished copper surface curved to focus the Sun’s rays onto Roman ships, causing them to catch fire. However, we have several reasons to suspect that the story of the burning mirror is just a myth and the Greeks of Syracuse never really built such a device.

First, the ancient Greeks were not technologically advanced enough to make such a device. A mirror that would focus sunlight with sufficient intensity to set ships on fire would have to be several meters wide. Moreover, the mirror would have to have a very precise parabolic curvature (a curvature derived from a geometric shape known as the parabola). The technology for manufacturing a large sheet of copper with such specifications did not exist in the ancient world.

Second, the burning mirror would have taken a long time to set the ships on fire. In an experiment conducted to determine whether a burning mirror was feasible, a device concentrating the Sun’s rays on a wooden object 30 meters away took ten minutes to set the object on fire; and during that time, the object had to be unmoving. It is unlikely that the Roman ships stayed perfectly still for that much time. Such a weapon would therefore have been very impractical and ineffective.

Third, a burning mirror does not seem like an improvement on a weapon that the Greeks already had: flaming arrows. Shooting at an enemy’s ships with flaming arrows was a common way of setting the ships on fire. The burning mirror and flaming arrows would have been effective at about the same distance. So the Greeks had no reason to build a weapon like a burning mirror.

Listening Passage

Refers to TPO 30 Integrating Writing.


The author in the reading passage claims that the burning mirror does not actually existed in the history of Greek, and provides three reasons to support his doubt. However, in the listening, the professor disagrees with what the author of the reading passage thinks, and provides three convincing evidences supporting her theory that the burning mirror did exist in the history.

In the reading passage, the author doubts the ancient Greek's technology, which he supposes is not advanced enough to build a large sheet of mirror that is efficient enough to burn the Roman navy's ships. On the contrary, the professor in the listening passage claims that the ancient Greeks did not have to build an entire mirror. Instead, they can build an enormous amount of small pieces of mirrors, and install them into parabola shape with their math knowledge, which is sufficient for the ancient Greeks. The theory of multiple pieces of small mirrors controdicts what the author in the reading passage doubts.

Secondly, In the reading, the author further doubts the time needed to set a piece of wood of the ancient Greek's ship on fire with the burning mirror. Again, the professor in the listening controdicts the reading passage, by claiming that it was not necessary for the ancient Greeks to set the wood on fire. Rather they could take advantages of the burning mirror to set other materials on fire, of the Roman ships, such as pitches. And it would only take several seconds to burn the pitches and spread the fire to the wood materials of the ships. This evidence again controdicts the reading passage.

Finally, the author of the reading passage doubts the necessity of the burning mirror, because the ancient Greeks already had flaming arrows, which has the same effective distance as the burning mirror. The professor in the listening, however, emphasizes the effect of surprise of the burning mirror. In this theory, she claims that the flaming arrows had been existing for a long time in the Greek's history, which meant the Roman navy had known well how to defense such an attack, and they would already have stayed alert to watch the flaming arrows. In contrast, burning mirror was such a novel weapon that the Romem were not aware of, and the ancient Greeks could use this advantage to attack the Roman navy's ships in surprise and thus more effectively. So the reading passage has failed again to defense its thesis.