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.
The article discusses about an ingenious weapon named burning mirror which was used by Greeks in Syracuse against Roman navy's attack. The weapon was consisting of a polished copper surface curve to set the enemy's ships on the fire. The author provides three reasons to support the idea that this weapon was not really made and used. However, the professor assumes these reasons to be unconvincing and refutes each reason.
First, the article claims that technology in the ancient world was not advanced to the level that make them capable to produce such a mirror with sufficient parabolic curvature and polish. However, the professor explains that the weapon did not has to consist of one big sheet of copper but instead it might has consisted of many tiny mirrors which were set together to form a big parabolic-shaped mirror to concentrate the sunlight.
Second, the passage states that setting the wood on fire with this weapon takes at least ten minutes according to experiments and also the ship had to be steady during the process. However, the lecturer avers that the Greeks did not used this device to set the wooden parts of the ship on the fire and rather used the sealing material named pitch as an igniter. That was more efficient way and just takes several seconds to get on fire and the ship had not be steady during this operation.
Third, the reading avers that the Greeks was using flaming arrows that time and that was more efficient way and they did not need to build such a device. Even though the professor agrees that they were using flaming arrows but he avers that the enemy was aware of this weapon and they was watching for the arrows and taking care to put down once the fire starts. Hence, this can be reason to build this innovative device which puts the ship on the fire suddenly and magically without making them noticed.
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Grammar and spelling errors:
Line 1, column 146, Rule ID: PROGRESSIVE_VERBS[1]
Message: This verb is normally not used in the progressive form. Try a simple form instead.
... against Roman navys attack. The weapon was consisting of a polished copper surface curve to s...
^^^^^^^^^^^^^^
Line 1, column 233, Rule ID: ENGLISH_WORD_REPEAT_BEGINNING_RULE
Message: Three successive sentences begin with the same word. Reword the sentence or use a thesaurus to find a synonym.
...ve to set the enemys ships on the fire. The author provides three reasons to suppor...
^^^
Line 3, column 246, Rule ID: DID_BASEFORM[1]
Message: The verb 'did' requires the base form of the verb: 'have'
Suggestion: have
...fessor explains that the weapon did not has to consist of one big sheet of copper b...
^^^
Line 5, column 234, Rule ID: DID_BASEFORM[1]
Message: The verb 'did' requires the base form of the verb: 'use'
Suggestion: use
... lecturer avers that the Greeks did not used this device to set the wooden parts of ...
^^^^
Line 5, column 458, Rule ID: HAVE_PART_AGREEMENT[2]
Message: Possible agreement error -- use past participle here: 'been'.
Suggestion: been
...nds to get on fire and the ship had not be steady during this operation. Third, ...
^^
Transition Words or Phrases used:
also, but, first, hence, however, really, second, so, third, as to, at least
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 15.0 10.4613686534 143% => OK
Auxiliary verbs: 3.0 5.04856512141 59% => OK
Conjunction : 14.0 7.30242825607 192% => OK
Relative clauses : 15.0 12.0772626932 124% => OK
Pronoun: 27.0 22.412803532 120% => Less pronouns wanted
Preposition: 39.0 30.3222958057 129% => OK
Nominalization: 1.0 5.01324503311 20% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1538.0 1373.03311258 112% => OK
No of words: 325.0 270.72406181 120% => OK
Chars per words: 4.73230769231 5.08290768461 93% => OK
Fourth root words length: 4.24591054749 4.04702891845 105% => OK
Word Length SD: 2.25650722402 2.5805825403 87% => OK
Unique words: 166.0 145.348785872 114% => OK
Unique words percentage: 0.510769230769 0.540411800872 95% => More unique words wanted or less content wanted.
syllable_count: 477.9 419.366225166 114% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 9.0 8.23620309051 109% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 0.0 2.5761589404 0% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 12.0 13.0662251656 92% => OK
Sentence length: 27.0 21.2450331126 127% => The Avg. Sentence Length is relatively long.
Sentence length SD: 45.9875436033 49.2860985944 93% => OK
Chars per sentence: 128.166666667 110.228320801 116% => OK
Words per sentence: 27.0833333333 21.698381199 125% => OK
Discourse Markers: 6.33333333333 7.06452816374 90% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 5.0 4.19205298013 119% => OK
Sentences with positive sentiment : 5.0 4.33554083885 115% => OK
Sentences with negative sentiment : 6.0 4.45695364238 135% => OK
Sentences with neutral sentiment: 1.0 4.27373068433 23% => More facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.135235907326 0.272083759551 50% => OK
Sentence topic coherence: 0.0603075715644 0.0996497079465 61% => OK
Sentence topic coherence SD: 0.0692700801745 0.0662205650399 105% => OK
Paragraph topic coherence: 0.093047805388 0.162205337803 57% => OK
Paragraph topic coherence SD: 0.0646429308876 0.0443174109184 146% => OK
Essay readability:
automated_readability_index: 14.4 13.3589403974 108% => OK
flesch_reading_ease: 52.53 53.8541721854 98% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 12.6 11.0289183223 114% => OK
coleman_liau_index: 10.45 12.2367328918 85% => OK
dale_chall_readability_score: 8.28 8.42419426049 98% => OK
difficult_words: 68.0 63.6247240618 107% => OK
linsear_write_formula: 10.5 10.7273730684 98% => OK
gunning_fog: 12.8 10.498013245 122% => OK
text_standard: 13.0 11.2008830022 116% => OK
What are above readability scores?
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Write the essay in 20 minutes.
Rates: 80.0 out of 100
Scores by essay e-grader: 24.0 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.