A periodic sentence is a long and frequently involved sentence, marked by suspended syntax, in which the sense is not completed until the final word — often with an emphatic climax. This is also called a period or a suspended sentence. 

Professor Jeanne Fahnestock notes in "Rhetorical Style" that the distinction between periodic and loose sentences "begins with Aristotle, who described types of sentences on the basis of how 'tight' or how 'open' they sounded."

Etymology

Periodic is from the Greek for "going around" or "circuit."

Examples and Observations

P.G. Wodehouse, "Something Fresh"

"In the almost incredibly brief time which it took the small but sturdy porter to roll a milk-can across the platform and bump it, with a clang, against other milk-cans similarly treated a moment before, Ashe fell in love."

"To believe your own thought, to believe that what is true for you in your private heart is true for all men, that is genius."

E.B. White, "Stuart Little"

"In the loveliest town of all, where the houses were white and high and the elms trees were green and higher than the houses, where the front yards were wide and pleasant and the back yards were bushy and worth finding out about, where the streets sloped down to the stream and the stream flowed quietly under the bridge, where the lawns ended in orchards and the orchards ended in fields and the fields ended in pastures and the pastures climbed the hill and disappeared over the top toward the wonderful wide sky, in this loveliest of all towns Stuart stopped to get a drink of sarsaparilla."

"Like the waters of the river, like the motorists on the highway, and like the yellow trains streaking down the Santa Fe tracks, drama, in the shape of exceptional happenings, had never stopped there."

I Corinthians 13

"And though I have the gift of prophecy, and understand all mysteries, and all knowledge; and though I have all faith, so that I could remove mountains, and have not charity, I am nothing."

Iain Sinclair, "Lights Out for the Territory"

"In the entrances of office blocks, just outside the revolving doors, on the fake marble steps (behind which can be glimpsed internal security personnel, pompous desks, escalators, hanging Jim Dine torsos) are these suits. Women in suits. Slightly shifty blokes. Insiders, badge-wearers, forced to taste the weather, to step outside — because they want to, have to, smoke."

"Democracy is that system of government under which people, having 60,000,000 native-born adults to choose from, including thousands who are handsome and many who are wise, pick out a Coolidge to be head of state. It is as if a hungry man, set before a banquet prepared by master cooks and covering a table an acre in area, should turn his back upon the feast and stay his stomach by catching and eating flies."

Dylan Thomas, "A Child's Christmas in Wales"

"Years and years ago, when I was a boy, when there were wolves in Wales, and birds the color of red-flannel petticoats whisked past the harp-shaped hills, when we sang and wallowed all night and day in caves that smelt like Sunday afternoons in damp front farmhouse parlors, and we chased, with the jawbones of deacons, the English and the bears, before the motor car, before the wheel, before the duchess-faced horse, when we rode the daft and happy hills bareback, it snowed and it snowed."

Saul Bellow, "Mr. Sammler's Planet"

"And even in the old days, in the days when he was 'British,' in the lovely twenties and thirties when he lived in Great Russell Street, when he was acquainted with Maynard Keynes, Lytton Strachey, and H. G. Wells and loved 'British' views, before the great squeeze, the human physics of the war, with its volumes, its vacuums, its voids (that period of dynamics and direct action upon the individual, comparable biologically to birth), he had never much trusted his judgment where Germans were concerned."

"Upon every other stage, the universal agent is love, by whose power all good and evil is distributed, and every action quickened or retarded. To bring a lover, a lady, and a rival into the fable; to entangle them in contradictory obligations, perplex them with oppositions of interest, and harass them with violence of desires inconsistent with each other; to make them meet in rapture and part in agony; to fill their mouths with hyperbolical joy and outrageous sorrow; to distress them as nothing human ever was distressed; to deliver them as nothing human ever was delivered, is the business of a modern dramatist."

James Boswell, "The Life of Samuel Johnson"

“Addison’s style, like a light wine, pleases everybody from the first. Johnson’s, like a liquor of more body, seems too strong at first, but, by degrees, is highly relished; and such is the melody of his periods, so much do they captivate the ear, and seize upon the attention, that there is scarcely any writer, however inconsiderable, who does not aim, in some degree, at the same species of excellence.”

Suspended Syntax and Balancing Acts

Richard A. Lanham, "A Handlist of Rhetorical Terms"

"Generally speaking, one might say that the period expresses a complete thought self-sufficiently; beyond this, it must have at least two members...'Periodic sentence' is a very rough English equivalent; it describes a long sentence that consists of a number of elements, often balanced or antithetical, and existing in perfectly clear syntactic relationship to one another. The phrase 'suspended syntax' is often used to describe it, since the syntactical pattern, and so the sense is not completed, is 'suspended,' until the end."

Richard A. Lanham, "Analyzing Prose"

"The periodic stylist works with balance, antithesis, parallelism and careful patterns of repetition; all these dramatize a mind which has dominated experience and reworked it to its liking. It is tempting to say that the periodic style humanizes time and we can say this, so long as we remember that to 'go with the flow' is as human as to oppose it..."

Periodic Sentences in Classical Rhetoric

James J. Murphy, "A Synoptic History of Classical Rhetoric"

"Isocrates' style is particularly characterized by the use of the periodic sentence, a style still recommended today as a means to achieve emphasis. Periodic sentences are formed by a series of clauses that build to the main clause, leading to a climactic effect. Here is an example of the periodic sentence from Isocrates' political treatise 'Panegyricus:'

"For when that greatest of all wars broke out and a multitude of dangers presented themselves at one and the same time, when our enemies regarded themselves as irresistible because of their numbers and our allies thought themselves endowed with a courage which could not be excelled, we outdid them both in a way appropriate to each."

Periodic Style vs Cumulative Style

Theresa Jarnagin Enos, "Encyclopedia of Rhetoric and Composition"

"A periodic style is usually described as 'compact' and as being characterized by 'suspended syntax.' In a periodic sentence, subordinate elements precede the main clause of the sentence; a periodic style is dominated by such constructions..."

"A periodic style is contrasted with a style variously described as 'free-running,' 'cumulative,' or 'loose.' The use of a free-running style reflects the combining and intermingling of multiple thoughts, one upon the other, and gives the impression that a writer is exploring ideas; the main clause of a loose sentence comes first, and less important details and qualifications follow. A periodic style, on the other hand, is marked by periods and denotes a refinement and a controlled emphasis on the part of the writer."

William Strunk, Jr., "The Elements of Style"

"The proper place in the sentence for the word or group of words that the writer desires to make most prominent is usually the end."

Suspended Sentence Patterns

Kristin Dombek, "Critical Passages: Teaching the Transition to College Composition"

"Ask students to look at a writing exercise or essay they've written, and to mark the most important sentence in each paragraph. Ask them to look for places where that sentence might be better placed either at the beginning or end of the paragraph and to think about why. Then ask them questions to help them reflect on the patterns they see: Are you a cumulative or a periodic thinker? What effect does it have when the controlling sentence, with the most important information and thinking, comes at the beginning of a paragraph? At the end?"

Advantages and Disadvantages of Periodic Sentences

Andrew Dousa Hepburn, "Manual of English Rhetoric"

"The periodic structure promotes energy, as it preserves the unity of the sentence and concentrates its strength in a single point. But it has an artificial appearance; it is unfitted for some kinds of composition, and its frequent recurrence is always disagreeable. It is not easy, without more help than the English language furnishes, to enable readers to retain in their minds the members of a complex thought, and at the close bind them easily and promptly into unity. To prevent obscurity and overtasking the attention, superfluous words and thoughts should be excluded from a period, and the members and clauses should be few and short. In arranging the clauses of the members, the same rule must be followed that governs the arrangement of the members of the period; the reader must not be led to suppose that the sentence is finished until it actually is so. When this rule is neglected, a period has the tediousness and feebleness of a badly constructed loose sentence."

Sources

"1 Corinthians." The Holy Bible, King James Version, Chapter 13, King James Bible Online, 2019.

Bellow, Saul. "Mr. Sammler's Planet." Stanely Crouch, Revised ed. edition, Penguin Classics, January 6, 2004.

Boswell, James. "The Life of Samuel Johnson." Penguin Classics, David Womersley (Editor), 1st edition, Paperback, Penguin Classics, November 19, 2008.

Capote, Truman. "In Cold Blood." Vintage International, Paperback, Vintage, February 1, 1994.

Dombek, Kristin. "Critical Passages: Teaching the Transition to College Composition." Language and Literacy Series, Scott Herndon, Celia Genishi, Dorothy S. Strickland,

Donna E. Alvermann, Teachers College Press, December 6, 2003.

Emerson, Ralph Waldo. "Self-Reliance." Paperback, CreateSpace Independent Publishing Platform, April 3, 2017.

Enos, Theresa Jarnagin (Editor). "Encyclopedia of Rhetoric and Composition: Communication from Ancient Times to the Information Age." 1st Edition, Routledge, March 19, 2010.

Fahnestock, Jeanne. "Rhetorical Style: The Uses of Language in Persuasion by Jeanne Fahnestock." Paperback, 1 Edition, Oxford University Press, October 12, 2011.

Hepburn, A. D. "Manual of English Rhetoric." Charlotte Downey, Scholars' Facsimiles & Reprints, Scholars Facsimilies & Reprint, October 1, 2001.

"If It's Obvious It Can't Be True." Old Life, January 22, 2016.

Isocrates. "Delphi Complete Works of Isocrates." Delphi Ancient Classics Book 73, Kindle Edition, 1 Edition, Delphi Classic, November 12, 2016.

Johnson, Samuel. "Preface to Shakespeare." 1st Edition, CreateSpace Independent Publishing Platform, October 23, 2014.

Jovanny, "Meaning of this quote?" Yahoo Answers, 2011.

Lanham, Richard A. "Analyzing Prose." Paperback, Second Edition, Bloomsbury Academic.

Lanham, Richard A. "A Handlist of Rhetorical Terms." Second Edition, University of California Press, November 15, 2012.

Murphy, James J. "A Synoptic History of Classical Rhetoric." Richard A. Katula, Michael Hoppmann, Paperback, 4th Edition, Routledge, 2013.

Sinclair, Iain. "Lights Out for the Territory." International Edition, Paperback, Penguin UK, October 28, 2003.

Strunk, William Jr. "The Elements of Style." E.B. White, Test Editor, Roger Angell, 4th Edition, Peason, August 2, 1999.

Thomas, Dylan. "A Child's Christmas in Wales." Hardcover, Orion Children's Books, October 2, 2014.

White, E.B. "Stuart Little." Garth Williams (illustrator), Paperback, Harper & Row, February 1, 2005.

Wodehouse, P.G. "Something Fresh." The Collector's Wode edition, Hardcover, Harry N. Abrams, April 7, 2005