science

Printing telegraph

Printing telegraph is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Printing telegraph rather than just read about it. In short: The printing telegraph is a device for sending and receiving telegraph messages. The sending operator uses a piano-style keyboard to directly input the text of the message, and the receiver instantly prints the text of the message on a paper strip.

Key takeaways

Printing telegraph belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Printing telegraph to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Printing telegraph from memory before moving on to harder problems.

Reference excerpt

The printing telegraph is a device for sending and receiving telegraph messages. The sending operator uses a piano-style keyboard to directly input the text of the message, and the receiver instantly prints the text of the message on a paper strip.

History The printing telegraph was invented by Royal Earl House in 1846. House's telegraph could transmit around 40 instantly readable words per minute, but was difficult to manufacture in bulk. The printer could copy and print out up to 2,000 words per hour. This invention was first put in operation and exhibited at the Mechanics Institute in New York. House's Type Printing Telegraph of 1849 was Royal Earl House's second and much improved type-printing instrument and was widely used on lines on America's east coast from 1850. David Hughes telegraph devices, which also had piano style keyboards, were very popular in France, where there were likely many more piano and harpsichord players than telegraphers. Early stock ticker machines are also examples of printing telegraphs.

Operation Input into device was facilitated through two 28-key piano-style keyboards. Each piano key represented a letter of the alphabet and when pressed, electronically transmitted that letter to a receiving printing telegraph as code. The requested letter would then be printed by that recipient telegraph. A "shift" key allowed an alternative character to be assigned to each key, for example a digit or punctuation mark instead of a letter. A 56-character typewheel at the sending end was synchronised to run at the same speed and to maintain the same angular position as a similar wheel at the receiving end. When the key corresponding to a particular character was pressed at the home station, it actuated the typewheel at the distant station just as the same character moved into the printing position, in a way similar to the daisy wheel printer. It was thus an example of a synchronous data transmission system.

Advantages The benefit of the Printing Telegraph is that it allows the operator to use a piano-style keyboard to directly input the text of the message. The receiver would then receive the instantly readable text of the message on a paper strip. This is in contrast to the telegraphs that used Morse Code dots and dashes which needed to be converted into readable text.

"The Western Union Telegraph Company is now putting in a new patent telegraph printing machine on the Chicago line and hereafter dispatches transmitted over this line will be printed as they are received at the office in this city. The machine is furnished with keys similar to a piano, each key representing a letter in the alphabet, and by a peculiar mechanical arrangement each letter is printed as it is received at the office. Thus all mistakes arising from blind chirography will be thoroughly appreciated by our citizens. The machine will be put into operation this afternoon."

Disadvantages Printing Telegraphs were quite temperamental and suffered frequent breakdowns. Transmission speed was also much slower than the Morse system. The complexity of the original House device meant that production was limited. An improved version was designed by George Phelps. The Globotype was invented by David McCallum as a response to problems with the printing telegraph.

Key layouts

Various layouts were produced to improve the efficiency of the keyboard system and accommodate several other alphabets.

Illustrations

Worked examples

Example 1 — a first encounter with Printing telegraph

Start with the simplest possible case. Write down what Printing telegraph claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Printing telegraph before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Printing telegraph ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Printing telegraph

In research: Printing telegraph appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Printing telegraph in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Printing telegraph is common in secondary-school and first-year university syllabi. It links to neighbouring topics Keyboard layouts, Telegraphy, so understanding it makes those chapters shorter.
In everyday life: Look for Printing telegraph outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Printing telegraph in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Printing telegraph means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Printing telegraph out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Printing telegraph in simple terms?

Why does Printing telegraph matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Printing telegraph?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Printing telegraph.