Also in 2024 Test B English, question 33; 2026 Practice Test C English, question 1.
Passage Invention of the Telegraph
Samuel Morse, an American inventor, is credited with creating the electronic telegraph, a communication device that allows users to send messages using a system of short and long pulses that represent letters, numbers, and punctuation. In 1843 the United States Congress passed the Telegraph Bill, which provided Morse with the funds to build an electric telegraph system.
Invention of the Telegraph
Earlier Signal Systems
Long before Samuel F. B. Morse electrically transmitted his famous message “What hath God wrought?” from Washington to Baltimore on May 24, 1844, there were signaling systems that enabled people to communicate over distances. Most were visual or “semaphore” systems using flags or lights. In the eighteenth century, such systems used an observer who would decipher a signal from a high tower on a distant hill and then send it on to the next station. The young American republic wanted just such a system along its entire Atlantic coast and offered a prize of $30,000 for a workable proposal. The framers of this legislation had no way of knowing that when they used the word “telegraph” to refer to this visual semaphore system, they would be offered an entirely new and revolutionary means of communication—electricity.
The Growth of an Idea
The idea of using electricity to communicate over distance is said to have occurred to Morse during a conversation aboard ship when he was returning from Europe in 1832. Michael Faraday’s recently invented electromagnet was much discussed by the ship’s passengers, and when Morse came to understand how it worked, he speculated that it might be possible to send a coded message over a wire. While a student at Yale College years before, he had written his parents a letter about how interesting he found the lectures on electricity. Despite what he had learned at Yale, Morse found when he began to develop his idea that he had little real understanding of the nature of electricity, and after sporadic attempts to work with batteries, magnets, and wires, he finally turned for help to a colleague at the University of the City of New York, Leonard D. Gale.
Gale was a professor of chemistry and familiar with the electrical work of Princeton’s Joseph Henry, a true pioneer in the new field. Well before Morse had his shipboard idea about a telegraph, Henry rang a bell at a distance by opening and closing an electric circuit. In 1831, he had published an article, of which Morse was unaware, that contained details suggesting the idea of an electric telegraph. Gale’s help and his knowledge of this article proved crucial to Morse’s telegraph system because Gale not only pointed out flaws in the system but showed Morse how he could regularly boost the strength of a signal and overcome the distance problems he had encountered by using a relay system Henry had invented. Henry’s experiments, Gale’s assistance, and, soon after, hiring the young technician Alfred Vail were keys to Morse’s success.
Obstacles and Opportunities
By December 1837, Morse had enough confidence in his new system to apply for the federal government’s appropriation, and during the next year he conducted demonstrations of his telegraph both in New York and Washington.
However, when the economic disaster known as the Panic of 1837 took hold of the nation and caused a long depression, Morse was forced to wait for better times. It was during this period that Morse visited Europe again and tried not only to secure patent protection overseas but to examine competing telegraph systems in England. . . .
By 1843, the country was beginning to recover economically, and Morse again asked Congress for the $30,000 that would allow him to build a telegraph line from Washington to Baltimore, forty miles away. The House of Representatives eventually passed the bill containing the Morse appropriation, and the Senate approved it in the final hours of that Congress’s last session. With President Tyler’s signature, Morse received the cash he needed and began to carry out plans for an underground telegraph line.
Realizing a Great Invention
Morse had hired the ingenious construction engineer Ezra Cornell to lay the pipe carrying the wire, and although Cornell did his job superbly, one of Morse’s partners, Congressman F. O. J. Smith, had purchased wire with defective insulation. Too much time had been wasted laying bad wire, and with the project on a rigid deadline, something had to be done quickly. Cornell suggested that the fastest and cheapest way of connecting Washington and Baltimore was to string wires overhead on trees and poles. The desperate Morse gave the go-ahead, and the line was completed in time for the dramatic and spectacularly successful link between the Supreme Court chamber of the Capitol building and the railroad station in Baltimore.
Soon, as overhead wires connected cities up and down the Atlantic coast, the dots-and-dashes method that recorded messages on a long moving strip of paper was replaced by the operator’s ability to interpret the code in real time. . . . Telegraph lines soon extended westward, and within Morse’s own lifetime they connected the continents of Europe and America.
“Invention of the Telegraph”—Public Domain/Library of Congress
legislation: Telegraph Bill
dots-and-dashes method: the short and long pulses of Morse code that are sent and received by telegraph operators
The first transatlantic electric telegraph message was sent in 1858, and by 1902 the British All-Red Line connected most of the world.
Source: U.S. Bureau of the Census. Historical Statistics of the United States, Colonial Times to 1970, Bicentennial Edition, Part 2. Washington, D.C., 1975.
Question
The details of the section “The Growth of an Idea” convey a central idea of the passage by suggesting that
- Athe collaborative efforts of colleagues resulted in successful communication over a wire.
- Ba great deal of interest and work was devoted to understanding how to use electricity to send signals.
- CFaraday’s invention of the electromagnet inspired the invention of the telegraph.
- Dcolleges like Yale played a great role in making new discoveries about electricity and its applications.
Show the answer
Correct answer: B
The question asks how a passage section helps convey a central idea of the passage. Paragraph 3 states that “Henry’s experiments, Gale’s assistance, and, soon after, hiring the young technician Alfred Vail were keys to Morse’s success.” The level of interest inspired Morse and others to work together to find a way to use electricity to send long-distance messages.
Option B is correct; the section helps convey a central idea because, overall, the section focuses on what fascinated Morse enough to begin his work and how others were just as interested and willing to work to achieve this goal.
Option A is incorrect because, although the word collaborative suggests that multiple people contributed to the telegraph’s success, the option does not clarify the research and effort needed in order to understand how to use electricity to send signals.
Option C is incorrect because when Morse came to understand how Faraday’s electromagnet worked, Morse wondered if it might be possible to send a coded message over a wire, but that thought later evolved into the telegraph only after more research and experimentation.
Option D is incorrect because the influence of what Morse learned at Yale was only a minor factor in his development of the telegraph.
Question analysis
This central idea question asks what the details in the section “The Growth of an Idea” suggest about the passage “Invention of the Telegraph.” The section covers Faraday’s electromagnet, Morse’s Yale lectures, and help from Gale, Henry and Vail, so students must judge which statement those details support as a group, and more than one choice sounds right.
- Grade level
- Grade 8 reading and task
- Compared with grade 7
- Above grade 7 Grade 7 central-idea questions usually have one clearly best summary. Here two paragraphs of names and events must be weighed, and several choices restate true details, so judging which fits the whole section is unusually demanding.
- Estimated difficulty
- Among the hardest on the SHSAT: a non-obvious approach, heavy reading, or a well-hidden trap.
- Thinking it demands
- Depth of knowledge 3, strategic thinking · mainly understand
- What makes it hard
- A very close wrong answer major
- Evidence in several places moderate
- The right answer is reworded moderate
- Evidence
- Answered from several paragraphs or stanzas
- Reading level
- Passage: about grade 11, 910 words; question and choices: about grade 12, 77 words.
- Students, last 30 days
- Not enough answers yet to show (it takes 10).
Why it is hard, traps and wrong answers (shows the answer)
Why it is hard
This is among the hardest questions in the set because the most tempting wrong choice reads like a paraphrase of the section’s final sentence. Rejecting it means noticing that the section never shows a message getting through and never shows Henry working with Morse, who had not even read his article. The right choice is vague by design, and only a summary of both paragraphs together shows that it fits better.
A very close wrong answer major Choosing the answer
The colleagues choice and the interest-and-work choice both describe effort spent on sending signals by wire; they part on one claim, that the effort “resulted in successful communication,” which the section never shows, the working line arriving in paragraph 7. (Embretson & Wetzel, 1987; Gorin & Embretson, 2006; Ascalon et al., 2007)
Evidence in several places moderate Working it out
The idea emerges only from details across two paragraphs, passengers discussing the electromagnet, Morse’s Yale letter, his failed attempts, Henry’s bell and article, Gale’s relay advice, taken together. (Kirsch & Mosenthal, 1990; Gorin & Embretson, 2006)
The right answer is reworded moderate Choosing the answer
The key names none of the section’s people, while the wrong choices echo its “colleague,” “over a wire,” Faraday’s electromagnet and Yale, and so look more firmly rooted in the text. (Freedle & Kostin, 1993; Kirsch & Mosenthal, 1990)
Strategy: Summarize paragraphs 2 and 3 together in one sentence of your own before reading the choices, then choose the statement closest to your summary, checking that every part of it is true of this section.
Traps
- Half right: One half of a two-part choice is right and the other is not.
- Too narrow: A single detail offered as the central idea or a summary, or a summary that keeps minor details and leaves out an essential part.
- Too broad or too strong: A choice overstates, generalizes, or uses absolute words the text does not support.
The wrong answers, classified
A Half right (King et al., 2004; Thissen, Steinberg & Fitzpatrick, 1989)
Rightly sees teamwork in the section’s close, but successful communication over Morse’s wire comes later, under “Realizing a Great Invention,” and the passage never shows Henry working with Morse.
C Too narrow (King et al., 2004)
Treats the spark as the whole story: Faraday’s electromagnet gave Morse the idea, but the section goes on to years of failed attempts and help from others.
D Too broad or too strong (King et al., 2004)
Inflates a passing mention: Morse’s Yale lectures appear once, and the section notes that despite them he had “little real understanding of the nature of electricity.”
Working it out, step by step
Figure out what the question asks
This asks what the section “The Growth of an Idea” says about a central idea, or main message. The section is paragraphs 2 and 3. Sum up both paragraphs together before you look at the choices.
List the section’s details
On the ship, Faraday’s electromagnet “was much discussed by the ship’s passengers.” Morse had found the electricity lectures at Yale interesting. He made “sporadic attempts” on his own. In paragraph 3, Henry “rang a bell at a distance by opening and closing an electric circuit.” Gale showed Morse how to use Henry’s relay system.
Find what the details share
Look at what links these details. Passengers talked about electricity. Morse was curious and kept trying. Henry ran tests and wrote an article. Gale gave advice. All of it is people taking an interest in electricity and working to send signals with it. That is the section’s main point. A working telegraph line does not appear until paragraph 7.
Check each choice
- A is close but wrong. Morse’s telegraph does not send a message until paragraph 7. Also, Henry never worked with Morse. At first, Morse did not even know about Henry’s article.
- B fits. It covers the interest and the work in both paragraphs.
- C is wrong. The electromagnet gave Morse the idea, but that is only the start of the section.
- D is wrong. Yale is only a small part of paragraph 2. And “Despite what he had learned at Yale,” Morse still knew little.
Choose the answer
The section shows lots of interest and effort aimed at sending signals with electricity. So the answer is B, “a great deal of interest and work was devoted to understanding how to use electricity to send signals.”
Why this answer and not the closest wrong one
A sounds like a summary of the section’s last sentence, which is why it tempts. But it claims the teamwork “resulted in successful communication,” and that only happens in a later section. B claims less, so every detail in paragraphs 2 and 3 fits it.
More questions like this
The original DOE question
The passage “Invention of the Telegraph” as printed (pages 146–148)
