A little over 2,200 years ago, the Roman navy attached 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 67 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 wetting 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.
The reading passage introduces a story from ancient Greek about how Greek army defended Roman’s attack by building huge copper mirrors to set the Roman navy’s ships on fire. The article certainly takes a disapproval attitude towards the authenticity of this story, while the lecture, with many supporting evidence, argues that setting up huge mirrors can be a reasonable strategy.
First, the article asserts that Greek cannot build such a huge mirror with precise parabolic shape simply due to technical limitations. In contrast to what the article suggests, the lecture contradicts it by proposing a solution, saying that technical limitation can be resolved by combining many tiny parts to form a huge mirror instead of building a big, single part at once.
Another evidence the article relies on is that setting up wood on fire by mirrors not only takes an unreasonable amount of time, but it also requires the object to be unmoved, which isn’t possible in real-world battle. The lecture; however, points out that ships are made by wood and many other materials, which some of those like pitch, are very easy to get caught on fire.
Lastly, the article holds its view by saying that there’s a far more efficient method to set enemy’s ships on fire, such as flaming arrows, while the lecture refutes the articles point by explaining that instead of using the common strategy, which the Roman navy was already used to, new tricks might be more effective.
Transition Words or Phrases used:
also, but, first, however, lastly, so, then, while, in contrast, such as, in contrast to
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 8.0 10.4613686534 76% => OK
Auxiliary verbs: 4.0 5.04856512141 79% => OK
Conjunction : 2.0 7.30242825607 27% => More conjunction wanted.
Relative clauses : 10.0 12.0772626932 83% => OK
Pronoun: 12.0 22.412803532 54% => OK
Preposition: 36.0 30.3222958057 119% => OK
Nominalization: 4.0 5.01324503311 80% => OK
Performance on vocabulary words:
No of characters: 1230.0 1373.03311258 90% => OK
No of words: 244.0 270.72406181 90% => More content wanted.
Chars per words: 5.04098360656 5.08290768461 99% => OK
Fourth root words length: 3.95227774224 4.04702891845 98% => OK
Word Length SD: 2.53984638751 2.5805825403 98% => OK
Unique words: 155.0 145.348785872 107% => OK
Unique words percentage: 0.635245901639 0.540411800872 118% => OK
syllable_count: 386.1 419.366225166 92% => OK
avg_syllables_per_word: 1.6 1.55342163355 103% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 0.0 3.25607064018 0% => OK
Article: 6.0 8.23620309051 73% => OK
Subordination: 2.0 1.25165562914 160% => OK
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 2.0 2.5761589404 78% => OK
Performance on sentences:
How many sentences: 7.0 13.0662251656 54% => Need more sentences. Double check the format of sentences, make sure there is a space between two sentences, or have enough periods. And also check the lengths of sentences, maybe they are too long.
Sentence length: 34.0 21.2450331126 160% => The Avg. Sentence Length is relatively long.
Sentence length SD: 58.015831759 49.2860985944 118% => OK
Chars per sentence: 175.714285714 110.228320801 159% => OK
Words per sentence: 34.8571428571 21.698381199 161% => OK
Discourse Markers: 12.5714285714 7.06452816374 178% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 0.0 4.19205298013 0% => OK
Sentences with positive sentiment : 4.0 4.33554083885 92% => OK
Sentences with negative sentiment : 3.0 4.45695364238 67% => OK
Sentences with neutral sentiment: 0.0 4.27373068433 0% => More facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.123870875984 0.272083759551 46% => OK
Sentence topic coherence: 0.0648711853105 0.0996497079465 65% => OK
Sentence topic coherence SD: 0.0705407945922 0.0662205650399 107% => OK
Paragraph topic coherence: 0.0755379717198 0.162205337803 47% => OK
Paragraph topic coherence SD: 0.0597511202332 0.0443174109184 135% => OK
Essay readability:
automated_readability_index: 19.7 13.3589403974 147% => OK
flesch_reading_ease: 36.97 53.8541721854 69% => OK
smog_index: 8.8 5.55761589404 158% => OK
flesch_kincaid_grade: 16.6 11.0289183223 151% => OK
coleman_liau_index: 12.54 12.2367328918 102% => OK
dale_chall_readability_score: 9.27 8.42419426049 110% => OK
difficult_words: 61.0 63.6247240618 96% => OK
linsear_write_formula: 14.5 10.7273730684 135% => OK
gunning_fog: 15.6 10.498013245 149% => OK
text_standard: 9.0 11.2008830022 80% => OK
What are above readability scores?
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Rates: 85.0 out of 100
Scores by essay e-grader: 25.5 Out of 30
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.