bomb cyclone / bombogenesis

GOES-16 satellite image of the January 2018 bomb cyclone blizzard that hit the northeastern United States

12 January 2023

A sudden and sustained drop in barometric pressure at the center of an extratropical cyclonic storm that indicates a strengthening of the storm system is known as a bomb cyclone or bombogenesis. The use of bomb is due to the metaphorically explosive nature of the change, and of course a cyclone is simply a circular storm, like a hurricane or tornado. Bombogenesis is a compound with the connecting -o- between the two elements, bomb and genesis, referring to the cause or start of the process. This latter term is modeled after cyclogenesis, referring to the start or strengthening of a cyclonic storm, which has been in use since at least 1925.

The meteorological sense of bomb was coined by Frederick Sanders and John Gyakum in a paper published in the October 1980 issue of Monthly Weather Review. The abstract of their paper reads:

By defining a “bomb” as an extratropical surface cyclone whose central pressure fall averages at least 1 mb h-1 for 24 h, we have studied this explosive cyclogenesis in the Northern Hemisphere during the period September 1976–May 1979. This predominantly maritime, cold-season event is usually found ~400 n mi downstream from a mobile 500 mb trough, within or poleward of the maximum westerlies, and within or ahead of the planetary-scale troughs.

A more detailed examination of bombs (using a 12 h development criterion) was performed during the 1978–79 season. A survey of sea surface temperatures (SST’s) in and around the cyclone center indicates explosive development occurs over a wide range of SST’s, but, preferentially, near the strongest gradients. A quasi-geostrophic diagnosis of a composite incipient bomb indicates instantaneous pressure falls far short of observed rates. A test of current National Meteorological Center models shows these products also fall far short in attempting to capture observed rapid deepening.

And meteorologists have been using bomb cyclone since at least 1987, when the term appears in an article by Stephen J. Colucci and J. Clay Davenport in the April issue of Monthly Weather Review:

Except for Bodurtha’s (1952) arbitrary definition of anticyclogenesis, a distinction is not made in all of these works between rapid and ordinary surface anticyclone intensification, in the same way that “bomb” cyclones are distinguished from nonexplosive cyclones.

The earliest use of bombogenesis that I’m aware of is in a 1989 master’s thesis by a Michael E. Adams, who describes his research as follows:

This research explores the processes responsible for the explosive cyclogenesis that took place over the Mid-West United States during 14–15 December 1987. Climatology shows that a high frequency of “bombogenesis” occurs over the ocean. Contrary to climatology, this storm's development occurred entirely over land. During an 18 hour period of deepening the cyclone experienced a central pressure drop of 27 mb. Moreover, within that time period the cyclone experienced a six hour pressure drop of 15 mb.

These terms began working their way out of meteorological jargon and into general discourse starting in the mid 1990s. The first was bombogenesis, which appears in an article in Rochester, New York’s Democrat and Chronicle of 16 November 1995 by local meteorologist Kevin Williams:

The storm itself developed from energy in the upper atmosphere. It strengthened rapidly as it moved over the warm Gulf Stream waters.

The explosive deepening of a storm is called “bombogenesis.”

When a storm “bombs,” it detonates a process in the atmosphere that brings together the ingredients that produce some of this planet’s greatest storms: the nor’easters.

Note that Williams is also using bomb as a weather-related verb here.

Bomb cyclone would take a while longer to enter general discourse, but it did by 31 December 2015 when it appears in an article in the Washington Post:

The same storm that slammed the southern United States with deadly tornadoes and swamped the Midwest, causing even greater loss of life, continued on to the Arctic. Sub-tropical air pulled there is now sitting over Iceland, and at what should be a deeply sub-zero North Pole, temperatures on Wednesday appeared to reach the melting point—more than 50 degrees above normal. That was warmer than Chicago.

Only twice before has the Arctic been so warm in winter. Residents of Iceland are bracing for conditions to grow much worse as one of the most powerful storms ever recorded blasts through the North Atlantic. This rare “bomb cyclone” arrived with sudden winds of 70 miles per hour and waves that lashed the coast.

Unfortunately, due to climate change we’ll be seeing a lot more of these terms in coming years.

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Sources:

Adams, Michael E. Anatomy of a “Bomb” Diagnostic Investigation of Explosive Cyclogenesis Over the Mid-West United States. North Carolina State University (master’s thesis), 1989, 11. Defense Technical Information Center.

Colucci, Stephen J. and J. Clay Davenport. “Rapid Surface Anticyclogenesis: Synoptic Climatology and Attendant Large-Scale Circulation Changes” (6 October 1986). Monthly Weather Review, 115.4, April 1987, 822. American Meteorological Society Journals.

Fears, Darryl and Angela Fritz. “Cataclysms from the North Pole to South America.” Washington Post, 31 December 2015, A1. ProQuest Historical Newspapers.

O’Conner, Patricia T. and Stewart Kellerman. “Bomb Cyclone: A Blast from the Past.” Grammarphobia (blog), 9 May 2022.

Oxford English Dictionary, third edition, December 2019, s.v. bombogenesis, n.; June 2015, s.v. cyclogenesis, n.

Sanders, Frederick and John R. Gyakum. “Synoptic-Dynamic Climatology of the “Bomb” (12 June 1980). Monthly Weather Review, 108.10, October 1980, 1589. American Meteorological Society Journals.

Williams, Kevin. “Folks, We Just Encountered ‘Bombogenesis.’” Democrat and Chronicle (Rochester, New York), 16 November 1995, 12A. ProQuest Historical Newspapers.

Photo credit: US National Oceanic and Atmospheric Administration (NOAA), 2018. Wikimedia Commons. Public domain image.

trivia / trivial

The board game Trivial Pursuit

11 January 2023

Trivia and trivial stem from the medieval Latin trivium. In classical Latin, a trivium was a place where three roads met. But in the Middle Ages, the word was applied to the curricula of schools and universities which consisted of the seven liberal arts, divided into two stages. The elementary stage, or trivium, consisted of grammar, rhetoric, and logic, and the advanced stage, or quadrivium, consisted of arithmetic, geometry, astronomy, and music. Trivial, therefore, meant something basic, learned early in one’s schooling. The noun trivia, meaning bits of inconsequential knowledge, is quite recent, however, dating only to the twentieth century and the game of trivia to the 1960s.

Trivium, in the medieval curricular sense, appears in English by the mid fifteenth century. John Lydgate refers to it in his version of the Secreta Secretorum (Secret of Secrets), a pseudo-Aristotelian encyclopedic text that was probably composed in Arabic in the tenth century. By the mid twelfth century it had been translated into Latin. The relevant passage from Lydgate’s poetic translation into English reads:

Yif I shulde talke / in scyencys tryval,
   Gynnyng at grameer / in signes and figurys,
Or of metrys / the feet to make equal,
   be tyme and proporcioun / kepyng my mesurys,
   This lady lyst nat / to parte the tresourys
      Of hire Substaunce / to my Childhood incondigne,
      Which am no aqueynted / with the mysys nyne.

(If I should speak in the sciences trivial, beginning with grammar in signs and figures, or of meters, making the feet equal in time and proportion, keeping my measures. This lady does not desire to give the treasures of her substance to my unworthy childhood, in which I am not acquainted with the nine muses.)

The adjective trivial meaning something in three parts appears at about the same time. From a mid-fifteenth century anonymous translation of Ranulf Higden’s Polychronicon, part of a listing on Higden’s source material:

Giraldus of Wales, which describede Topographie of Irlonde, Itinerary of Wales, and the Lyfe of Kinge Henry the Secunde, under a triuialle distinccion

(Gerald of Wales, who wrote the Topography of Ireland, the Itinerary Through Wales, and the Life of King Henry II, in trivial [i.e., three] parts.)

Higden’s original Latin reads triplici distinctione. John Trevisa had penned an earlier English translation of Higden’s work, but he did not translate this section; he simply copied the Latin list of sources.

It wouldn’t be until the Early Modern period that the adjective trivial would come to mean ordinary, everyday, inconsequential, or trifling things. From an essay by Thomas Nashe that was published in 1589, in which he uses the adjective to refer to the translators he usually consults:

I'le turne backe to my first text, of studies of delight; and talke a little in friendship with a few of our triuiall translators.

And Shakespeare used it in the inconsequential sense in Henry VI, Part 2. In Act 3, Scene 1, various nobles are debating whether the Duke of Gloucester should die even though the king still trusts him; the Duke of Suffolk advocates killing him:

But in my minde, that were no pollicie:
The King will labour still to saue his Life;
The Commons haply rise, to saue his Life;
And yet we haue but triuiall argument,
More then mistrust, that shewes him worthy death.

The sense of trivia meaning bits of inconsequential knowledge had yet to appear, but a step in that direction was taken by a 1716 work by John Gay, Trivia: or, the Art of Walking the Streets of London. In Gay’s work, Trivia is the name of the muse who inspires him to write. The opening of Gay’s work reads:

Through Winter Streets to steer your Course aright,
How to walk clean by Day, and safe by Night,
How jostling Crouds, with Prudence, to decline,
When to assert the Wall, and when resign,
I sing: Thou Trivia, Goddess, aid my Song,
Thro’ spacious Streets conduct thy Bard along.

Trivia is also the Roman name of Hecate, goddess of magic, night, crossroads, and travelers, so she is an appropriate muse for Gay’s work. And he is also alluding to Book 4 of Virgil’s Aeneid which contains the lines:

Nocturnisque Hecate triviis ululata per urbes
et Dirae ultrices et di morientis Elissae,
accipiter haec

(Hecate, whose name is howled by night in city streets, and avenging Furies and gods of dying Elissa: hear me now.)

But that is not the only reference to Virgil and to trivium in Gay’s work. The work also bears an epigraph from Virgil’s Eclogue number 3, a dialogue between Menalcas and Damoetas:

Non tu, in Triviis, Indocte, solebas St[r]identi, miserum, stipula, disperdere Carmen?

(Wasn’t it you at the crossroads, unskilled, who used to destroy a wretched tune with your shrieking pipe?)

But with a change in punctuation (the punctuation is a later intervention by editors and not original to Virgil), tu, in Triviis indocte could be read by an eighteenth-century reader like Gay as you, uneducated in the Trivium. By using this epigraph, Gay is denigrating his critics before they can respond to his work, simultaneously accusing them of ignorance and of being poor poets and musicians.

Gay is also playing off Alexander Pope’s Rape of the Lock, which had been published a few years before in 1712, and which would have been very familiar to his readers, whose opening lines read:

What dire offence from am’rous causes springs,
What mighty contests rise from trivial things,
I sing—This verse to Caryl, Muse! Is due.

Gay’s work did not use trivia in the sense of inconsequential knowledge, but it inspired writer and scholar of eighteenth-century literature Logan Pearsall Smith to use Trivia as the title of a 1902 collection of essays, which he credited to a fictional Anthony Woodhouse. His own mother said of the collection that it “began nowhere, ended nowhere and led to nothing.” The book was initially a failure, printed in few numbers privately, but it has been more successful in later reprints.

Other uses of the noun trivia would follow, like this passage from the Glasgow Herald of 21 July 1920:

Mr. Arnold Bennett, in his recent account of a yachting cruise, seems to have deliberately avoided the “show places,” and has made a fascinating narrative out of the apparently trivial things; crowds in marketplaces, the window contents of little shops, the manner of ordinary people pursuing their ordinary avocations. Mr. Bennett is of course one of the rare observers with the equally rare gift of imparting colour to the commonplace. But his method suggests the amount of human interest and knowledge that may lurk in the trivia of holiday experience.

The game of trivia, played in various forms but which all feature questions about inconsequential knowledge appears in the 1960s. It got its start among college students in the United States, and can now be found on television game shows, in pubs and bars, and in board game form. Here is an early reference in Columbia University’s Columbia Spectator of 5 February 1965:

Has anyone ever asked you what was the name of the Lone Ranger’s nephew? Has anyone ever challenged you to name the snake that appeared in “We’re No Angels?” Maybe someone has dared you to name Superman’s Kryptonic parents? If any of these things have happened to you then, no doubt, you have been involved in a game of “trivia.”

Trivia is a game which is played by countless young adults who on the one hand realize that they have misspent their youth and yet, on the other hand, do not want to let go of it. It is a combination of “Information Please” and psychoanalysis, in which participants try to stump their opponents with the most minute details of shared childhood experiences.

And in a way, the entire Wordorigins.org website consists of trivia.

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Sources:

Gay, John. Trivia: or, the Art of Walking the Streets of London. London: Bernard Lintott, 1716, sig. B. Eighteenth Century Collections Online.

Goodgold, Edwin. “Trivia: Glorious Entertainment.” Columbia Spectator (Columbia University, New York), 5 February 1965, 4. Columbia Spectator Archive.

Higden, Ranulf. Polychronicon Ranulphi Higden Monachi Cestrensis, vol. 1 of 8. Babington, Churchill, ed. London: Longman, et al., 1865, 25. London, British Library, Harley MS 2261. HathiTrust Digital Archive.

“Holiday Values.” Glasgow Herald, 21 July 1920, 8. Google News.

Lydgate, John. Secreta Secretorum (c.1450). In Lydgate and Burgh’s Secrees of Old Philosoffres. Robert Steele, ed. Early English Text Society, ES 66. London: Kegan Paul, Trench, Trübner, 1894, 49, lines 1527–33. London, British Library, Sloane MS 2464. HathiTrust Digital Archive.

Middle English Dictionary, 2018, s.v. trivial(le, adj.

Nashe, Thomas. “To the Gentlemen Students of Both Universities.” In Robert Greene. Menaphon: Camillas Alarum to Slumbering Euphues. London: Thomas Orwin for Sampson Clarke, 1589, sig. **3. Early English Books Online.

Oxford English Dictionary, second edition, 1989, s.v. trivia, n., trivial, adj. and n., trivium, n.

Pettit, Katherine Denshaw. Guide to the Logan Pearsall Smith Collection. San Antonio, Texas: Trinity University, 1987, 11.

Pope, Alexander. The Rape of the Lock, 1.1–3.

Rogers, Pat. “Why ‘Trivia?’ Myth, Etymology, and Topography. Arion, 12.3, Winter 2005, 19–31. JSTOR.

Shakespeare, William. Henry VI, Part 2. 3.1. Mr. William Shakespeares Comedies, Histories & Tragedies. London: Isaac Jaggard and Edward Blount, 1623, 132. First Folio, Folger copy #68.

Smith, Logan Pearsall (using pseudonym Anthony Woodhouse) . Trivia. London: Chiswick Press, 1902. HathiTrust Digital Archive.

Virgil. Eclogues. Georgics. Aeneid: Books 1–6. H. Rushton Fairclough and G.P. Goold, eds and trans. Loeb Classical Library 63. Cambridge: Harvard UP, Eclogue 3.26–27, 38–39 and Aeneid 4.609–11, 462–63. Loeb Classical Library Online.

Image credit: Pratyeka, 2016. Wikimedia Commons. Licensed under a Creative Commons Attribution-Share Alike 4.0 International license.

bigwig

1793 colored mezzotint of three affluent physicians in large, powdered wigs

9 January 2023

A bigwig is a person of some importance. The origin of the term is exactly what one might expect; it arises out of the eighteenth-century practice of wealthy and important personages wearing large, powdered wigs. But in its earliest uses the term is particularly associated with physicians, only later being applied more generally to important people.

Big wig appears first as a noun phrase referring to the wig, not the person wearing it. We see such a literal phrase in Oliver Goldsmith’s 1759 essay “On Dress”:

For my entertainment the beauty had all that morning been improving her charms, the beau had put on lace, and the young doctor a big wig, merely to please me.

The earliest use, that I know of, of bigwig applied to a person, again a physician, is in George Alexander Stevens’s 1772 song Tom O’ Bedlam.

Here’s a Bumber, my Boys, may we still find the way,
To speak what we know, and to know what we say.
Ye big Wigs of Gresham some Nostrum compound,
To keep our Heads clear and preserve our Hearts sound.
May Greatness and Goodness as partners agree,
May our sons, like ourselves, social sing, WE ARE FREE!
And may we, self conscious, presumption despise,
Nor e’er be so mad as to thing ourselves wise.

Note the capitalization (it was a common eighteenth-century practice to capitalize all nouns) indicates that big Wig was not yet considered a single lexical item but was still considered a noun phrase with an adjective.

And we also see it in Joseph Atkinson’s 1788 play A Match for a Widow. In this scene, set in a tavern, a doctor, Quack, is in conversation with two soldiers, Gauge and Drill:

Quack. O, curse long stories, they make me yawn—let’s drink about, here’s the king’s health.

Drill. Aye, God bless him—he’s a good master, if he’d but make the big wigs give the poor soldiers better pay.

Gauge. You minister—what, to Doctor the constitution as you do your patients—by killing them.

Quack. No reflections on my calling, if you please, Mr. Gauge.

And here, the italicization of big wig indicates that the phrase was by this point considered a single unit, a lexical item.

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Sources:

Atkinson, Joseph. A Match for a Widow. London: C. Dilly, 1788, 2.1, 19. Eighteenth Century Collections Online (ECCO).

Goldsmith, Oliver. “On Dress.” The Bee. Being Essays on the Most Interesting Subjects. London: J. Wilkie, 1759, 38. Eighteenth Century Collections Online (ECCO).

Oxford English Dictionary, third edition, December 2008, s.v. bigwig, n.

Stevens, George Alexander. “Tom O’ Bedlam.” Songs, Comic and Satyrical. Oxford: 1772, 229. Eighteenth Century Collections Online (ECCO).

Image credit: Robert Dighton, 1793, Wellcome Collection. Public domain image.

actinium

Actinium-255 medical radioisotope. The blue glow is due to the ionization of the surrounding air by alpha particles.

6 January 2023

The discovery of actinium, element 89, is generally credited to chemist André-Louis Debierne in 1899, a year after the Curies discovered radium. Debierne named the new radioactive element after the Greek άκτις (actis), meaning beam or ray. In this way, it is the Greek equivalent of the Curies’ Latinate radium.

Debierne announced his discovery the following year in the journal Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences (Weekly Reports of the Meetings of the Academy of Sciences), and his article was quickly translated into English and republished in the British Journal of the Chemical Society:

Actinium: A New Radio-active Element. By A. Debierne
(Compt. rend., 1900, 130, 906–908).—The new radio-active element, actinium, belonging to the iron group (compare this vol. ii, 20), may be obtained in a more concentrated form by submitting the substances containing it to the following operations.

But Debierne’s claim is disputed, with some chemists believing that his 1899 discovery was in error and that credit for the element’s discovery should go to Friedrich Oskar Giesel, who isolated the element in 1902. Giesel dubbed his discovery emanium, due to its radioactive emanations, but as both Giesel and Debierne claimed to have identified the same element, the older name received priority.

This was not the first time the name actinium was involved in a controversial elemental discovery. In 1881, Thomas Lamb Phipson claimed to have discovered a new element, one that changed chemically when exposed to sunlight. He also dubbed it actinium, but while his name has the same Greek root, Lamb’s name differed semantically. He named it for the supposed element’s actinic properties; both actinic and actinism had been in use since 1845 to describe chemicals and chemical processes affected by light rays. For example, photosynthesis and film photography are actinic processes. Phipson announced his discovery in the 24 June 1881 issue of Chemical News:

It took from 4 to 8 hours’ exposure to direct sunlight to give to this portion under the glass a very slight fawn-colour.

Of course these phenomena could not be due to any compound of silver; nevertheless, the specimens were tested for silver, and with great care, but without the slightest result. In fact, no actinic substance has been met with that will darken in the sunshine, become white again in the dark, and will not darken under a sheet of ordinary window glass. It was hinted that I was dealing with a new element (to be called “Actinium”); but the continuation of my experiments lead me to believe that the phenomena described above may probably be due to the presence of sulphide of barium and protoxide of iron in the specimens, rather than some unknown metal.

While in his initial announcement Phipson hedged the idea that he had discovered a new element, a few months later he was more assertive in his claim:

My experiments on the new metal Actinium have been interrupted in various ways, and by the fact that, for the sake of my health, I have been compelled to leave London for a short time. […] As the only method which I have yet discovered of separating oxide of actinium from oxide of zinc is by means of caustic soda, I am not certain that I have, hitherto, obtained the process perfectly exempt from oxide of zinc, even after four or five treatments at boiling heat.

Phipson was mistaken in his belief that he had discovered a new element, and few chemists at the time accepted his claim. His claim and this earlier sense of actinium are now mere footnotes in the history of science.

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Sources:

“Actinium.” Journal of the Chemical Society, 78.2, 1900, 350. HathiTrust Digital Archive.

Kirby, H.W. “The Discovery of Actinium.” Isis, 62.3, Autumn 1971, 290–308. JSTOR.

Oxford English Dictionary, third edition, November 2010, s.v. actinium, n., actinic, adj., actinism, n.

Phipson, Thomas Lamb. “Correspondence: Actinium.” Chemical News, 43.1142, 14 October 1881, 191. HathiTrust Digital Archive.

———. “On a Curious Actinic Phenomenon.” Chemical News, 43.1126, 24 June 1881, 283. HathiTrust Digital Archive.

Waggoner, William H. “The First Actinium Claim.” Journal of Chemical Education, 53.9, 1 September 1976, 580.

Photo credit: Oak Ridge National Laboratory, 2015. Wikimedia Commons. Licensed under a Creative Commons Attribution 2.0 Generic license.

atmospheric river

2010 image from the GOES 11 satellite showing an atmospheric river flowing from the eastern Pacific to California

5 January 2023

In current meteorological jargon, an atmospheric river is a narrow stream of very humid air that often carries a series of storms with it. Perhaps the most famous of these is the so-called Pineapple Express that flows from Hawaiian waters to the west coast of North America. But the term is not a new one, having existed for some 150 years.

And metaphorical use of river to refer to a mass of a flowing substance is even older, dating to at least the fourteenth century when it appears in a Wycliffite translation of Job 29.6:

I wesh my feet with butter, and the ston helde to me ryueres of oile.

The Vulgate uses rivos. So, the underlying metaphor is an old, obvious, and common one.

But the specific phrase atmospheric river dates to at least 1865, when John Mullan used it in his survey of the American West to describe a belt of warm air that flowed from Missouri to Montana:

The meteorological statistics collected during a great number of years have enabled us to trace an isochimenal line across the continent, from St. Joseph’s, Missouri, to the Pacific; and the direction taken by this line is wonderful and worthy the most important attention in all future legislation that looks towards the travel and settlement of this country. This line, which leaves St. Joseph’s in latitude 40°, follows the general line of the Platte to Fort Laramie, where, from newly introduced causes, it tends north-westwardly, between the Wind River chain and the Black Hills, crossing the summit of the Rocky Mountains in latitude 47°; showing that in the interval from St. Joseph’s it had gained six degrees of latitude. Tracing it still further westward it goes as high as 48°, and develops itself in a fan-like shape in the plains of the Columbia. From Fort Laramie to the Clark’s Fork, I call this an atmospheric river of heat, varying in width from one to one hundred miles. On its either side, north and south, are walls of cold air, and which are so clearly perceptible that you always detect them when you are upon its shores.

The use in the present-day meteorological sense dates to at least 1871. From an article on meteorology by T.B. Maury in Scribner’s Monthly from February of that year:

But the Gulf Stream is a great liquid avenue, over whose blue waters roll mighty masses of atmosphere and ride in terrifio [sic] triumph the fiercest cyclones.

Its track is overhung by aqueous vapor, and is thus a region of rarefied air and of a low barometer.

Here is a natural ATMOSPHERIC RIVER-BED. Its banks are colder and heavier air and its bottom is the bosom of the sea itself. The storm, as it passes along this great highway carved out for it by an ordinance of the Almighty, may rub and fret against its bounds, as the locomotive, thundering along the curve of the road, may chafe against and batter the steel edges of the unyielding rail. It may even, like the engine, leave and leap its track and fly off in tangential fury. But it has a track, an ordained track, in which man may ordinarily expect to find it.

And from later in the article:

Moreover, as the Gulf Stream of the Atlantic is the natural channel for the storms which beat upon the British coast, so the Kuro-Siwo, or Black Stream of Japan, a mightier gulf stream than ours, whose recurving waters wash and warm the Pacific coasts of America, affords a pathway for cyclones generated in the Pacific Ocean and the China seas. This latter region of the earth is near the very womb and nursery of the tempest and the typhoon. The storm engendered in its bosom finds, in the atmospheric river-bed overhanging the smoking waters of the Kuro-Siwo, a free and ready transit.

Chalk another one up to the recency illusion.

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Sources:

Maury, T.B. “Weather-Telegrams and Storm-Forecasts by the American Signal Service.” Scribner’s Monthly, 1.4, February 1871, 418, 421. HathiTrust Digital Archive.

Mullan, John. Miners and Travelers’ Guide to Oregon, Washington, Idaho, Montana, Wyoming, and Colorado. New York: William M. Franklin, 1865, 39–40. HathiTrust Digital Archive.

Oxford English Dictionary, third edition, June 2010, s.v. river, n.1.

Image credit: US Naval Research Laboratory, Monterey, 2010. Public domain image.