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 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 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.
Last try:06/19/2020 02:11Word Count: 340
The reading and the lecture both are about a weapon used in the war between Greeks and Romans. The author feels that the burning mirror used as a weapon is just an assumption made by people, and says that Greeks are not advanced in technology at that time, time taken by the burning mirror is too long to burn a substance and they already had flaming arrows which are similar to a burning mirror. The lecturer refutes all three points made by the author and argues for each of the assertions.
First of all, the professor in the lecture points out that Greek mathematicians know the properties of a parabola and they constructed a large mirror by clubbing small pieces. On the other hand, the reading posits that the technology of making a burning mirror was not available at that time. Moreover, it mentions that technology is needed for minute specifications to make the device.
Next, Roman boats were made of other materials apart from wood. On top of that, to fill the gaps between the woods the Romans used a sticky substance called pitch. This pitch material was easy to set on fire within seconds after exposure to a burning mirror and also it can catch fire whether the boat is still or moving. The passage counteracts this point and states that this particular device needs to concentrate on a still object for at least 10 minutes to set fire. Moreover, the object has to be still to get fired. This particular experiment did on wood, so it disproves this theory as Romans had other materials by which they made their boats.
Finally, the Romans cannot see the burning rays from a mirror. When the fires catch their boats they would be surprised as there is no evidence of burning flames in their reach. It would be possible only when they did not use flaming arrows. This particular point is argued in the reading, mentioning that in spite of having flaming arrows as the common weapon they would not have used this device.
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Grammar and spelling errors:
Line 1, column 398, 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.
... which are similar to a burning mirror. The lecturer refutes all three points made ...
^^^
Transition Words or Phrases used:
also, finally, first, if, moreover, second, so, still, apart from, as to, at least, first of all, in spite of, on the other hand, on top of that
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 15.0 10.4613686534 143% => OK
Auxiliary verbs: 5.0 5.04856512141 99% => OK
Conjunction : 9.0 7.30242825607 123% => OK
Relative clauses : 14.0 12.0772626932 116% => OK
Pronoun: 30.0 22.412803532 134% => Less pronouns wanted
Preposition: 43.0 30.3222958057 142% => OK
Nominalization: 5.0 5.01324503311 100% => OK
Performance on vocabulary words:
No of characters: 1600.0 1373.03311258 117% => OK
No of words: 344.0 270.72406181 127% => OK
Chars per words: 4.6511627907 5.08290768461 92% => OK
Fourth root words length: 4.30665032142 4.04702891845 106% => OK
Word Length SD: 2.37926412628 2.5805825403 92% => OK
Unique words: 173.0 145.348785872 119% => OK
Unique words percentage: 0.502906976744 0.540411800872 93% => More unique words wanted or less content wanted.
syllable_count: 487.8 419.366225166 116% => OK
avg_syllables_per_word: 1.4 1.55342163355 90% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 5.0 3.25607064018 154% => OK
Article: 8.0 8.23620309051 97% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 3.0 2.5761589404 116% => OK
Performance on sentences:
How many sentences: 16.0 13.0662251656 122% => OK
Sentence length: 21.0 21.2450331126 99% => OK
Sentence length SD: 59.5068273394 49.2860985944 121% => OK
Chars per sentence: 100.0 110.228320801 91% => OK
Words per sentence: 21.5 21.698381199 99% => OK
Discourse Markers: 9.0 7.06452816374 127% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 1.0 4.19205298013 24% => OK
Sentences with positive sentiment : 2.0 4.33554083885 46% => More positive sentences wanted.
Sentences with negative sentiment : 8.0 4.45695364238 179% => OK
Sentences with neutral sentiment: 6.0 4.27373068433 140% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.119969196498 0.272083759551 44% => OK
Sentence topic coherence: 0.0407852082891 0.0996497079465 41% => OK
Sentence topic coherence SD: 0.0443249106905 0.0662205650399 67% => OK
Paragraph topic coherence: 0.0798104712991 0.162205337803 49% => OK
Paragraph topic coherence SD: 0.044029323011 0.0443174109184 99% => OK
Essay readability:
automated_readability_index: 11.2 13.3589403974 84% => Automated_readability_index is low.
flesch_reading_ease: 67.08 53.8541721854 125% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 9.1 11.0289183223 83% => OK
coleman_liau_index: 9.69 12.2367328918 79% => OK
dale_chall_readability_score: 7.52 8.42419426049 89% => OK
difficult_words: 62.0 63.6247240618 97% => OK
linsear_write_formula: 13.0 10.7273730684 121% => OK
gunning_fog: 10.4 10.498013245 99% => OK
text_standard: 10.0 11.2008830022 89% => OK
What are above readability scores?
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Write the essay in 20 minutes.
Rates: 60.0 out of 100
Scores by essay e-grader: 18.0 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.