an ingenious weapon called a "burning mirror"

English as a Second Language Preparation for and help with the TOEFL® Test and
1

The reading:

A little over 2,200 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 rally 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 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.

My answer:
The reading and the lecture discuss whether Greeks defended themselves with a burning mirror or it is just a myth. The reading passage provides several reason to prove that the Greeks of Syracuse never built such a weapon. However, the lecturer casts doubt on each of the points made in the reading by providing supporting details.

To begin with, the reading passage states the ancient Greeks were not technologically advanced, and in the ancient world, the technology for manufacture a large sheet of copper to make a mirror did not exist. However, the lecturer mentions that to make such a mirror, there is no need of a single sheet of copper. Greek people knew the property of parabola, and would have assembled the small pieces of copper in a large sheet in a parabolic curvature. This directly challenges the information asserted in the reading.

In addition, the reading states that ships should have been steady for a long time to produce fire by the burning mirror, which is unlikely for sailing ships. However, the lecturer states that the burning mirror takes longer for wood to produce fire. Nonetheless, the ships were made up of different materials. She gives an example of a sticky substance called pitch, which is used to seal the gape between wood parts. This substance catches fire in few seconds by a burning mirror. Thus, the fire would spread quickly from the pitch to surrounding woods of ships. This appears to be a contradiction to the assertion stated in the reading.

Last but not least, the reading passage claims that Greeks already had a weapon called flaming arrows, so they had no reason to build a weapon like a burning mirror. However, the lecturer states that when fire is produced by a mirror, the ships would see only mirror. On the other hand, in the flamming arrows, they could see the fire. Thus using a burnning mirror would have been more effective. This disputes the point made in the reading.

TOEFL listening discussions: What is the main weakness of the student’s essay?

2

Please, correct and rate and essay as well!!

The question discussed in the reading passage and lecture is whether the weapon known as burning mirror is a mithy or in fact existed. The reading presents some arguments showing that this tools was never built by the Greeks while the professor refutes those arguments.

For starters, the reading says that burning mirror was very advanced and the technology used to build a devise like this didn´t exist in the ancient world. However, the professor explains that actually the Greeks built small burning mirrors and arranged them forming a parabolic shape.

Second, the passage states that this weapon would take to long to set the ships on fire and says that an experiment was made showing this. The professor disagrees with the experiment, saying that it used wooden. According to the professor, using other materials the weapon would be more quicly and effective.

Last, the reading holds the opinion that the burning mirror would bring any improvement on a weapon that the Greeks already had, the flaming arrows. Conversely, the lecturer explains that this weapon would be a surprise to the ennemies, since they could not see it.

3

Please, correct and rate and essay as well!!

The question discussed in the reading passage and lecture is whether the weapon known as burning mirror is a mithy or in fact existed. The reading presents some arguments showing that this tools was never built by the Greeks while the professor refutes those arguments.

For starters, the reading says that burning mirror was very advanced and the technology used to build a devise like this didn´t exist in the ancient world. However, the professor explains that actually the Greeks built small burning mirrors and arranged them forming a parabolic shape.

Second, the passage states that this weapon would take to long to set the ships on fire and says that an experiment was made showing this. The professor disagrees with the experiment, saying that it used wooden. According to the professor, using other materials the weapon would be more quicly and effective.

Last, the reading holds the opinion that the burning mirror would bring any improvement on a weapon that the Greeks already had, the flaming arrows. Conversely, the lecturer explains that this weapon would be a surprise to the ennemies, since they could not see it.

4

Hi Chaitalivpatel, another excellent essay. You capture all of the main points from the lecture, though maybe you could have explained a couple of the minor secondary points a little more clearly - see below. But apart from a few minor errors, your essay is very clear and natural-sounding; I would rate it a 4.5 out of 5.

5

Hi Nayara, I am afraid your essay was not quite as good as Chaitalivpatel’s, but understand that he set the bar very high! Your overall structure is good, and you focused on the correct three differences between the reading and the lecture. But your analysis of the lecture was not very detailed and your explanations were not always clear. Overall, I would rate this a 3.5 out of 5.