A Guide to the GRE/Extracting Content

Pay close attention to what facts can be deduced based on the information in the passage, and understand the meaning of each term and concept.

Reading passages on the GRE will typically introduce and explain concepts quickly, and go on to discuss them assuming you have a full understanding of what they are. Make sure to understand each item's meaning.

“Telegraph” is typically used to describe 	communication using electrical signals 	relayed through wires, such as in the 	system promulgated by Samuel Morse in 5	the early 1800s. In fact, the terms 	“telegraph” and “telegraphy” refer to any 	communication over long distance, such as 	through modern-day telephones or internet 	communications. Likewise, “telegraph” 10	refers to predecessors of electrical 	communication, including the once used 	semaphore line. A semaphore line is a system of relaying 	communications over long distances. Also 15	known as a “Chappe Telegraph”, the 	system is entirely mechanical and relies on 	no electricity or electronics. Rather, the 	relay is accomplished by a series of towers 	with flags or mechanical arms that could be 20	arranged in a particular way so as to 	convey a message, which would be passed 	on to the next tower which similarly 	arranged itself in this fashion. First widely 	used in Europe in the late 1700s, such 25	means of communication were instrumental 	in the coalition war against Napoleon in 	Iberia during the early 19th century and 	remained useful in Europe until replaced 	by electrical telegraphs. Though perhaps a 30	primitive means compared to modern 	technology, the achievements of semaphore 	lines were unprecedented for their time and 	contemporaneous technology. Practice

1. What is a semaphore line? How does it work and what does it do?

2. The author mentions the wars against Napoleon primarily to

(A) give an example of successful use of semaphore lines (B) demonstrate the difficulties of communicating over long distances in years past (C) show how semaphore lines could communicate in multiply languages (D) illustrate the problems with predecessors of the semaphore line (E) explain why semaphore lines would've been more widely used without political disharmony

3. According to the passage, what was the main cause of the decline of the semaphore line?

(A) the end of the coalition wars in Europe (B) the lack of widespread electricity to power the system (C) the introduction of a more efficient means of communication (D) the rise of telegraphy in the developed world (E) the introduction of the Chappe Telegraph 3.03 Extracting Content & Drawing Inferences

Answers to Practice Questions
1. A semaphore line is a series of towers with mechanical arms which convey messages over long distances by flagging the arms in a certain fashion. According to the passage, they were widely used in Europe before the introduction of the electrical telegraph.

2. (A)

At this point in the passage, the author is explaining how semaphore lines worked and how they were used. The coalition war in Iberia is given as an example of the successful use of the semaphore line. The remaining answers are typical GRE “trap” responses. Answer (B) is incorrect because, while this might be an underlying subject of the passage generally, the use of semaphore lines in the coalition is given as an example of the successful use of semaphore lines, not of the difficulty of using them. Choice (C) is similarly incorrect because languages and translations are not mentioned at all.

Answer (D) is incorrect because the predecessors of the semaphore line are not discussed in detail in the passage, and the passage does not make any comparisons between them and the semaphore line. Choice (E) is similarly outside the scope of the passage - while a war is mentioned, nothing in the passage states that this war had any effect on the use of semaphore lines. If anything, it provided an opportunity for them to be used.

3. (C)

This comes straight from lines 28-29. Often the correct answer to a reading question will be correct but stated in a vague form such as this, and stand amidst four incorrect “trap” answers. Choice (A) is incorrect because, while the coalition wars are mentioned as an instance of the use of the semaphore line, their end is not cited as the cause of semaphore lines' decline. Similarly, (B) is incorrect because semaphore lines do not require electricity - electrical telegraphs do. (D) is incorrect because “telegraphy” according to the author means any form of long-distance communication, and thus there was no “rise” of telegraphy after the semaphore - the semaphore was a telegraph. Finally, (E) is a trap answer - a “Chappe Telegraph” is just another name for a semaphore line according to the passage.

This passage is a good example of a strange word that it is important to understand and define subconsciously while reading a passage.