Fact-checked by Grok 2 weeks ago

Jacks

Jacks, also known as jackstones or knucklebones, is a traditional dexterity game typically played by children using a set of small, six-pronged metal or plastic objects called jacks and a small rubber ball.^[1] Players scatter the jacks on a flat surface, toss the ball into the air, and attempt to pick up a predetermined number of jacks—starting with one and increasing progressively—before catching the ball on its bounce, requiring hand-eye coordination and quick reflexes.^[2] The objective is to complete a sequence of rounds without dropping the ball or failing to retrieve the jacks, with the player who lasts longest or completes the most rounds declared the winner.^[1] The game's origins trace back to prehistoric times, with archaeological evidence indicating it was played in ancient civilizations including Egypt, where knucklebones served as precursors to dice in randomization games.^[3] It spread widely through Greek and Roman societies, where it was known as astragaloi or tali, using the ankle bones (astragali) of sheep; ancient sources, such as Sophocles, attributed its invention to the mythological figure Palamedes during the Trojan War, though it likely predates this as an Asian or Egyptian import.^[4] By the colonial era in America, jacks had evolved to incorporate iron or bone pieces similar to modern versions, remaining a popular pastime among children for over two millennia due to its simplicity and minimal equipment needs.^[5]^[2] Variations of jacks exist globally, adapting local materials like seeds, stones, or beans in place of knucklebones, and rules can differ in the number of jacks used (often five or ten) or the complexity of maneuvers, such as "pigs in the pen" or "around the world."^[2] Today, the game promotes fine motor skills and concentration, continuing as an enduring folk activity often taught across generations in educational and recreational settings.^[1]

Children's Game

Gameplay and Rules

Jacks is played with a set of small, star-shaped metal or plastic pieces known as jacks, typically numbering 10, and a small rubber ball approximately 1 inch (25 mm) in diameter.^[6] The game requires a flat, smooth surface such as a table, floor, or pavement to scatter the jacks evenly.^[7] The core gameplay involves turns where players scatter the jacks on the surface, toss the ball into the air to bounce once, and use one hand to pick up a predetermined number of jacks before catching the ball on its first bounce with the same hand.^[6] Play progresses through rounds called "onesies" (picking up 1 jack), "twosies" (2 jacks), and so on, up to "tensies" (all 10 jacks), with the player continuing until a miss occurs.^[6] A miss includes failing to catch the ball before its second bounce, dropping a jack, or disturbing other jacks on the ground.^[8] The winner is the first player to successfully complete all rounds from onesies to tensies without errors, though in informal play, the game may end when a player reaches the highest round or after a set number of turns.^[6] Upon a miss, the player's turn ends, and the next player begins at onesies; some versions require restarting the entire sequence from the beginning on the next turn, known as "scrubs."^[6] Double-bouncing the ball or dropping jacks incurs the same penalty, emphasizing precision and hand-eye coordination.^[6] Common variations add challenges to the basic mechanics, such as "over-the-line," where players place their hand flat on the ground as an imaginary fence and toss jacks over it one through ten times while managing the ball; "eggs in the basket," involving cupping one hand to scoop jacks into the palm like collecting eggs, using the opposite hand to catch the ball; and "around-the-world," requiring a circular motion with the hand around the bouncing ball before catching it, performed for each round.^[9]^[10] These modifications, drawn from traditional play, increase difficulty and are often negotiated among players before starting.^[9] The game adapts easily for different ages and group sizes, accommodating 2 or more players by rotating turns in a circle or pairs sitting opposite each other.^[7] Younger children may use fewer jacks (e.g., 6) and simpler rounds to build skills, while older players or groups incorporate speed rounds or two-handed picking for added competition.^[8]^[6] Solo practice focuses on personal progression, making it versatile for individual or social play.^[6]

History and Cultural Significance

The game of jacks traces its origins to ancient civilizations, where it was played with knucklebones known as astragaloi, the ankle bones of sheep or goats, dating back to around 2000 BCE in regions including ancient Egypt, Greece, and Rome.^[11] Archaeological evidence, such as knucklebones found in Egyptian tombs from the second millennium BCE and Greek artifacts depicting children tossing and catching them, indicates it served both as a game of dexterity and a precursor to dice for divination.^[12] In ancient Greece, the game was popular among children of both genders, as shown in terracotta figurines from the 4th century BCE portraying girls engaged in play, while Roman sources describe it as tali, often using sheep ankle bones thrown and caught in progressive challenges.^[13] During the medieval and early modern periods in Europe, the game evolved into variants such as "fivestones" or "dibs," typically played with five small stones or bones, maintaining its core mechanics of tossing and catching.^[14] This continuity from ancient practices is evident in European folklore and illustrations from the 16th to 18th centuries, where it remained a common pastime for children using readily available pebbles or animal bones.^[15] European colonists introduced the game to the Americas in the 17th and 18th centuries, where it was adapted as "jackstones" using stones, seeds, or whatever materials were at hand, becoming a staple of colonial childhood recreation alongside other imported pastimes.^[16] By the early 20th century, the game underwent commercialization in the United States with the introduction of mass-produced metal jacks, which replaced natural materials and standardized the six-pointed design, leading to a surge in popularity as an accessible, gender-neutral toy.^[17] This shift coincided with the addition of a rubber ball in the early 20th century, enhancing gameplay and making it suitable for indoor and outdoor settings, with sets becoming widely available through toy manufacturers.^[18] Jacks holds significant cultural value as a symbol of childhood innocence and simplicity, evoking nostalgic imagery of unstructured play in literature and media. Therapeutically, jacks is utilized in occupational therapy to develop hand-eye coordination and fine motor skills, as the rapid tossing and catching motions challenge bilateral integration and dexterity in children and adults alike.^[19] Globally, jacks manifests in diverse forms, such as the Korean variant gonggi, played with small stones or plastic pieces since ancient times, emphasizing precision in catching while tossing, and sharing the game's dexterity focus across East Asian traditions.^[20] While the rise of digital entertainment has contributed to its decline among younger generations since the late 20th century, jacks has seen revival in educational and therapeutic contexts, where it promotes cognitive and physical development without screens.^[21]

People

Sports and Athletics Figures

Brian Jacks (born 1946) is a British judoka renowned for his achievements in the middleweight division during the 1970s. He secured a bronze medal at the 1972 Summer Olympics in Munich, marking Great Britain's first Olympic judo medal. Jacks also claimed bronze at the 1967 World Judo Championships in Salt Lake City and won European Championships in 1970 and 1973. His competitive career spanned multiple Olympics, including appearances in 1964 and 1976, where he finished 11th in the latter.^[22]^[23]^[24] George Jacks (born 1946) was an English professional footballer who played as a midfielder in the 1960s and 1970s. He made over 160 appearances for Millwall between 1965 and 1972, contributing to their notable unbeaten run of 59 home games at The Den from 1964 to 1967. Jacks also played for Queens Park Rangers and Gillingham, appearing in the Football League for several seasons before retiring. His career highlighted the competitive lower divisions of English football during that era.^[25]^[26] Ron Jacks (born 1948) is a Canadian swimmer who competed internationally in freestyle and butterfly events during the 1960s and early 1970s. Representing Canada at three consecutive Summer Olympics, he participated in the 1968 Mexico City Games, where he placed 16th in the 400-meter freestyle, and the 1972 Munich Games, competing in the 200-meter butterfly and 400-meter freestyle. Jacks set multiple Canadian national records and won medals at the Commonwealth and Pan American Games, including gold in the 4x200-meter freestyle relay at the 1966 British Empire and Commonwealth Games. His contributions helped elevate Canadian swimming on the global stage.^[27]^[28]^[29] Sam Jacks (1915–1975) was a Canadian recreation director and sports innovator best known for inventing the sport of ringette in 1963. Working for the North Bay Parks and Recreation Department in Ontario, Jacks developed ringette as a non-contact team sport for girls, using a rubber ring and straight sticks on ice to promote skill and strategy over physicality. He collaborated with Mirl "Red" McCarthy to establish initial rules, leading to the first organized games that year. Jacks's creation has grown into an international women's sport, with the Sam Jacks Trophy awarded annually at World Ringette Championships in his honor. He was posthumously inducted into the Ringette Canada Hall of Fame and other sports halls for his contributions to recreational athletics.^[30] Will Jacks (born 1998) is an English cricketer who plays as a right-handed batting all-rounder, specializing in off-spin bowling. He made his first-class debut for Surrey in 2018 and has since become a key T20 performer, scoring explosive innings in the Vitality Blast, including a century off 47 balls in 2022. Jacks earned his international cap for England in 2021, debuting in ODIs and T20Is, and was selected for the 2022 ICC Men's T20 World Cup squad. His aggressive style has made him a standout in limited-overs cricket, with notable performances in the Indian Premier League for Royal Challengers Bengaluru in 2024.^[31]^[32]^[33] Al Jacks (1935–2023) was an American college football coach whose career focused on quarterback development and program building in NCAA Division II and III levels. He served as head coach at Clarion State College (now PennWest Clarion) from 1963 to 1981, compiling a record of 104–84–7 and becoming the program's winningest coach. Jacks also briefly led Williams College in 1971 and had earlier roles at smaller institutions. A former quarterback at Penn State, he emphasized disciplined, fundamentals-based offenses during his tenure. His legacy includes induction into the Clarion University Sports Hall of Fame in 1989.^[34]^[35]^[36]

Arts, Entertainment, and Academia Figures

James Jacks (1947–2014) was an American film producer and executive renowned for his work on blockbuster films during the late 20th and early 21st centuries. Born on December 29, 1947, he began his Hollywood career as a vice president of acquisitions at Universal Pictures, later advancing to senior vice president of production, where he oversaw notable projects including Do the Right Thing (1989) and Field of Dreams (1989). In 1992, Jacks co-founded Alphaville Films with Sean Daniel, producing hits such as Dazed and Confused (1993), Tombstone (1993), The Mummy (1999), and its sequels, which collectively grossed over $1.1 billion worldwide. He died of a heart attack on January 20, 2014, at age 66.^[37] L. P. Jacks (1860–1955), born Lawrence Pearsall Jacks on October 9, 1860, in Nottingham, England, was an influential English philosopher, educator, and Unitarian minister whose work bridged theology, ethics, and modern philosophy. Ordained in 1888, he served as a minister in Liverpool and Birmingham before becoming principal of Manchester College, Oxford, in 1903, a position he held until 1931, emphasizing holistic education that integrated moral and intellectual development. Jacks founded and edited the Hibbert Journal from 1902 to 1948, a quarterly review that advanced discussions on religion, science, and continental philosophy, including contributions from thinkers like Henri Bergson. His key writings, such as The Alchemy of Thought (1910) and The Education of the Whole Man (1931), explored ethical naturalism and critiques of mechanism in human life, influencing Unitarian thought and public discourse on spirituality. He died on February 17, 1955, in Oxford.^[38] Robert Jacks (1943–2014) was a prominent Australian visual artist known for his minimalist and abstract works in painting, sculpture, and printmaking. Born on March 8, 1943, in Melbourne, he studied sculpture at Prahran Technical College (1958–1960) and painting at the Royal Melbourne Institute of Technology (1960–1962), holding his first solo exhibition in 1966 at Gallery A, Melbourne. Jacks' career included international residencies in Toronto (1967) and New York (1969), where he developed geometric grid-based abstractions inspired by urban environments and nature, evolving into conceptual pieces like rubber-stamped artist books and triangular forms evoking Texas landscapes. Returning to Australia in 1978, he lectured at Prahran College (1984–1988) and settled in rural Victoria in 1989, producing works held in major collections such as the National Gallery of Victoria and the British Museum. A retrospective at the Ian Potter Centre in 1990 highlighted his contributions to Australian abstract art; he was appointed an Officer of the Order of Australia (AO) and died on August 14, 2014.^[39] Susan Jacks (1948–2022) was a Canadian singer-songwriter celebrated for her soulful voice and contributions to 1970s pop music as the lead vocalist of The Poppy Family. Born Susan Elizabeth Pesklevits on August 19, 1948, in Saskatoon, Saskatchewan, she began performing as a child on CBC television shows like Music Hop before forming The Poppy Family in 1968 with then-husband Terry Jacks, scoring international success with "Which Way You Goin' Billy?" (1970), which topped charts in Canada and reached No. 2 on the US Billboard Hot 100, selling over two million copies. The band's psychedelic folk-rock style also yielded hits like "Where Evil Grows," leading to tours across Canada, Europe, and Expo '70 in Osaka. After the group's 1973 disbandment, Jacks pursued a solo career with tracks such as "You Don't Know What Love Is" (1973) and later worked as a songwriter and producer in Nashville; she died on April 25, 2022, in Surrey, British Columbia, at age 73.^[40] Terry Jacks (b. 1944) is a Canadian musician, record producer, and environmental activist best known for his 1974 international hit "Seasons in the Sun." Born Terrence Ross Jacks on March 29, 1944, in Winnipeg, Manitoba, and raised in Vancouver, he started as a guitarist and singer with The Chessmen before co-founding The Poppy Family in 1968, producing their breakthrough "Which Way You Goin' Billy?" (1970). Transitioning to solo work, Jacks adapted Rod McKuen's English lyrics to Jacques Brel's "Le Moribond," releasing "Seasons in the Sun" which topped charts in the US and Canada, selling over 11 million copies worldwide and earning a Juno Award. In the late 1980s, he shifted focus to environmentalism, founding the Environmental Watch of British Columbia to combat industrial pollution, particularly from pulp mills, and producing the documentary The Warmth of Love (2000) on sustainable living. Jacks received the Order of British Columbia in 2003 for his advocacy.^[41] Tyler Jacks is an American biologist and leading cancer researcher at the Massachusetts Institute of Technology (MIT), renowned for pioneering genetically engineered mouse models (GEMMs) to study tumor genetics. Born in 1961, he earned a B.A. in biology from Harvard in 1983 and a Ph.D. from the University of California, San Francisco, in 1988 under Harold Varmus, focusing on oncogenes. Joining MIT's faculty in 1992, Jacks developed innovative gene-targeting techniques in mice to model human cancers like lung and pancreatic tumors, enabling breakthroughs in understanding genetic drivers, metastasis, and immunotherapy responses. As founding director of the Koch Institute for Integrative Cancer Research (2007–2021) and a Howard Hughes Medical Institute investigator (1994–2021), his lab has advanced organoid models for precision medicine; Jacks co-directs the Ludwig Center at MIT and serves on boards of Amgen and Thermo Fisher Scientific. His contributions earned election to the National Academy of Sciences and awards including the AACR Outstanding Achievement Award (2013).^[42] Digby Jacks (1945–2011) was a British trade union leader and student activist whose career centered on education and labor rights in the public sector. Born on May 16, 1945, in London, he studied biology at King's College London and rose through student politics to become the first communist president of the National Union of Students (NUS) from 1971 to 1973. During this tenure, Jacks mobilized 40,000 students against Margaret Thatcher's proposed cuts to higher education funding, forcing a policy reversal through sustained lobbying and demonstrations that strengthened NUS's influence on government. Post-NUS, he served as a divisional officer for the Association of Scientific, Technical and Managerial Staffs, then as assistant general secretary of the Manufacturing, Science and Finance Union (1980s–1990s), advocating for workers in education, research, and finance sectors, including as secretary of the Alliance for Finance. Jacks also sat as a Labour councillor in Hounslow and authored Student Politics and Higher Education (1975); he died on October 21, 2011.^[43]

Music

Bands Named Jacks

Jacks was a pioneering Japanese psychedelic rock band formed in 1966, emerging from the folk-oriented group Nightingale established in 1965 by Yoshio Hayakawa (guitar and vocals), Suehiro Takahashi, and Eiri Matsubara.^[44] By early 1967, the lineup expanded to include bassist Hitoshi Tanino and drummer Takasuke Kida, with lead guitarist Haruo Mizuhashi joining later that year after Takahashi's departure, shifting their sound toward jazz-infused psychedelia influenced by the British Invasion and global folk-rock trends.^[45] The band released their debut and only full-length album, Vacant World (also known as Karappo no Sekai), in September 1968 on Express Records, featuring raw, experimental tracks blending Hayakawa's baritone vocals and austere guitar with Mizuhashi's fuzz-laden leads, which garnered cult status for its innovative fusion of Western rock and Japanese enka elements.^[46] Jacks disbanded in August 1969 amid internal tensions and limited commercial success, though their brief output has since influenced subsequent generations of Japanese rock musicians.^[47] The Jacks was an American indie rock band from Los Angeles, California, founded in 2016 by guitarist Tom Hunter and bassist Scott Stone, who reconnected from their middle school cover band days to create original material drawing on classic rock and British Invasion vibes.^[48] The lineup included vocalist and rhythm guitarist Jonny Stanback, Hunter on lead guitar and vocals, Stone on bass and vocals, and drummer Josh Roossin, emphasizing energetic live performances that blended gritty riffs with melodic hooks.^[49] Their debut self-titled EP arrived in June 2019, followed by the 2020 EP Remember You—produced by Joe Chiccarelli and featuring revamped tracks like "Just a Little Bit"—and the full-length album Slowdance in 2021, which showcases their evolution toward polished yet raw indie rock anthems about relationships and urban life.^[50] As of 2025, the band has been inactive since the 2021 release of Slowdance, with no new tours or recordings.^[51] The band built a dedicated following through relentless touring and holiday singles, maintaining a presence in the Southern California scene through 2021.^[52] Other groups named Jacks include short-lived acts like the Melbourne-based punk rock 'n' roll trio The Jacks, active in the early 2010s with a self-titled album mixing high-energy punk and rockabilly, though they remain lesser-known outside local circuits.^[53]

Songs and Other Musical References

One notable song featuring "jacks" in its title is "Tracy Jacks" by the British rock band Blur, released on their 1994 album Parklife. The track narrates the mundane life of a middle-aged civil servant named Tracy Jacks, blending Britpop with social commentary on suburban ennui.^[54] Another example is "Sometimes Jacks Rule the Realm" by the American rock band 311, from their 2003 album Evolver. This song explores themes of power dynamics and rebellion, with "jacks" metaphorically representing underdogs or tricksters who occasionally seize control.^[55] In hip-hop, "jacks" appears as slang in lyrics, often denoting payphones or acts of theft to obtain money. Big L's 1998 track "Ebonics" from the album Lifestylez ov da Poor & Dangerous explicitly defines it: "cribs is homes, jacks is payphones," serving as a glossary of urban vernacular to educate listeners on street terminology.^[56] Similarly, in UGK's 1992 song "Short Texas" from The Southern Way, the phrase "jacked all his money" uses "jacked" to describe robbing, implying "jacks" as ill-gotten gains in Southern rap contexts.^[57] The term "jacks" also refers to audio connectors integral to music production history. Originating from telephone switchboard plugs invented in 1878, these cylindrical connectors were adapted for audio use by the early 20th century, with the 1/4-inch (6.35 mm) version becoming a standard in professional studios for guitars, microphones, and amplifiers due to its durability and low signal loss.^[58] The smaller 1/8-inch (3.5 mm) headphone jack, a miniaturization for portable devices, emerged in the 1950s and revolutionized consumer music playback, enabling widespread use in Walkmans and early digital players by the 1980s.^[59] In folk and children's music, "jacks" connects to the traditional game through rhymes and songs. The counting rhyme "This Old Man," popularized in 20th-century recordings like those by folk artists in the 1940s, draws inspiration from the jacks game (also known as knucklebones), where players bounce a ball and pick up jacks in sequence—mirroring the song's structure: "This old man, he played one / He played knick-knack on my thumb / With a knick-knack paddywhack / Give a dog a bone / This old man came rolling home."^[18] Early versions trace to 19th-century British folk traditions, evolving into American children's repertoire by the mid-20th century.

Places

Jacks Mountain

Jacks Mountain is a prominent stratigraphic ridge within the Ridge and Valley physiographic province of the Appalachian Mountains in central Pennsylvania. It primarily spans Mifflin and Huntingdon counties, with portions extending into Snyder and Union counties, and forms part of the border between Huntingdon and Mifflin counties along its ridge line. The ridge reaches elevations of up to 2,332 feet and stretches as a long, narrow feature through the region's characteristic folded terrain. The mountain is covered in mature hardwood forests dominated by oak species, which provide essential habitat for wildlife such as white-tailed deer, wild turkey, black bear, ruffed grouse, and forest interior birds including raptors like bald eagles and broad-winged hawks. These ecosystems support biodiversity typical of the Appalachian foothills, with the forested slopes serving as migration corridors and protected areas for native species. Named after Jack Armstrong, an 18th-century fur trader known for a 1743 dispute involving the confiscation of a horse from a Delaware Indian, the mountain saw extensive logging operations in the 19th century as part of Pennsylvania's broader timber boom that cleared vast Appalachian woodlands for industry. Today, significant portions fall within State Game Lands 112, encompassing over 6,400 acres managed by the Pennsylvania Game Commission for public hunting, wildlife habitat preservation, and low-impact recreation. Recreational access includes the historic Thousand Steps trail—a 1,043-step staircase constructed in 1936 by workers of the Harbison-Walker Refractories Company for silica mining access—which forms a key segment of the 80-mile Standing Stone Trail and climbs 850 feet to the ridge crest.^[60] The area borders Rothrock and Bald Eagle state forests, facilitating extended hiking, birdwatching, and scenic overlooks amid the preserved natural landscape.

Jacks River

The Jacks River is a river in Fannin and Murray counties, northwest Georgia, USA, originating in the Blue Ridge Mountains within the Chattahoochee National Forest. It flows approximately 17 miles northward through the remote Cohutta Wilderness, characterized by steep terrain and dense forests, before joining the Conasauga River near the Tennessee border.^[61] The river's course traverses rugged gorges and multiple small tributaries, contributing to the region's hydrological network in the upper Coosa River basin. The river's natural features include sections ideal for trout fishing, with both native and stocked species such as rainbow and brown trout thriving in its clear, cold waters, which are designated as a trout stream by the Georgia Department of Natural Resources. Whitewater enthusiasts navigate Class II to V rapids in several segments, particularly around falls and ledges, while the surrounding landscape features thick rhododendron thickets and mixed hardwood forests typical of the southern Appalachian ecoregion.^[62] Ecologically, the Jacks River supports diverse native fish populations, including the federally threatened Conasauga logperch (Percina jenkinsi), which inhabits riffles and pools along its length, highlighting its role in preserving endemic aquatic biodiversity.^[63] Named after a Cherokee man who, according to tradition, ferried travelers across the river on his back for a fee, the river holds historical significance tied to early European American settlement and logging activities in the late 19th and early 20th centuries.^[64] The surrounding Cohutta Wilderness, encompassing the river, was designated by Congress on January 3, 1975, under Public Law 93-622, to protect its pristine condition and prevent further development, making it one of Georgia's largest wilderness areas at 36,977 acres. Conservation efforts emphasize maintaining water quality and habitat integrity, with the area popular for backpacking along segments of the Benton MacKaye Trail, which intersects the Jacks River Trail and offers remote access to the waterway.^[65] Recreational use focuses on low-impact activities like fishing, kayaking, and hiking, with the river's ecology benefiting from annual volunteer cleanups organized by groups such as the Conasauga River Alliance, which remove debris to sustain aquatic habitats and prevent pollution. These events, part of broader initiatives like Georgia's Rivers Alive program, engage local communities in preserving the river's clarity and supporting its native species amid increasing visitor numbers.^[66] The river's protected status ensures long-term ecological health, balancing human enjoyment with the preservation of its wild character.

Other Uses

Mechanical and Lifting Devices

Mechanical jacks are devices designed to lift heavy loads by applying force through mechanical advantage, commonly used in scenarios requiring elevation or support of equipment without relying on electrical power. These tools operate on principles of leverage, screws, or fluid dynamics to multiply input force, enabling one person to handle weights far exceeding their physical capacity. Unlike electrical connectors, mechanical jacks focus solely on physical lifting and positioning tasks.^[67] Common types include screw jacks, which employ a threaded rod or worm gear to provide precise, controlled lifting over short distances, ideal for stable, incremental adjustments. Hydraulic jacks, such as bottle jacks (compact and vertical-lifting) and floor jacks (with extended handles for horizontal positioning), utilize incompressible fluid to transmit force efficiently. Ratchet jacks, often lever-operated with a toothed mechanism, are typically used for quick vehicle elevation and feature a ratcheting system to hold loads securely during operation.^[67]^[68]^[69] The operation of mechanical jacks relies on force multiplication through mechanical advantage. Screw and ratchet jacks achieve this via leverage and gear ratios, where input torque on a handle or lever converts to greater output force on the load. Hydraulic jacks specifically follow Pascal's principle, which states that pressure applied to a confined fluid is transmitted undiminished in all directions, allowing a small force over a large piston area to generate a larger force on a smaller piston: P = \frac{F}{A}, where P is pressure, F is force, and A is area. This enables lifting capacities from several tons with minimal effort.^[70]/Book%3A_University_Physics_I_-Mechanics_Sound_Oscillations_and_Waves(OpenStax)/14%3A_Fluid_Mechanics/14.05%3A_Pascals_Principle_and_Hydraulics) In automotive applications, jacks like scissor or bottle types are essential for tire changes and undercarriage repairs, supporting vehicles up to several tons on stable surfaces. Construction sites employ floor and hydraulic jacks to position heavy machinery or support structures during assembly, while industrial settings use them in elevator mechanisms, where hydraulic variants drive pistons to raise and lower cabs reliably. Screw jacks find use in precise alignment tasks, such as leveling foundations or machinery bases.^[69]^[71]^[72] The origins of mechanical jacks trace to the 17th and 18th centuries, when they were developed for maritime use to lift or separate heavy ship components, as evidenced in shipbuilding treatises and artifacts from vessels like the early 18th-century ship Queen Anne's Revenge. Modern hydraulic jacks emerged in the 19th century, with Richard Dudgeon patenting a portable hydraulic press in 1851 (US Patent 8,203), revolutionizing compact lifting for industrial applications by incorporating a self-contained fluid reservoir.^[73]^[74] Safety is paramount with mechanical jacks, as overloading or instability can lead to catastrophic failure. Each jack must bear a marked rated load capacity, which should not be exceeded and ideally selected with a 25-30% safety margin above the anticipated load to account for dynamic forces. Operation requires placement on flat, solid surfaces like concrete to ensure stability, and loads should always be supported by locking mechanisms or jack stands rather than the jack alone, preventing tipping or collapse during maintenance.^[75]^[76]^[77]

Electrical and Audio Connectors

Electrical jacks, also known as phone jacks or audio jacks, are cylindrical electrical connectors designed primarily for transmitting analog audio signals and low-voltage power in various devices.^[78] These connectors facilitate reliable, temporary connections between audio equipment, power sources, and telecommunications hardware, evolving from early telephone technology to modern consumer and professional applications.^[79] Common types include phone jacks, which come in sizes such as the 1/4-inch (6.35 mm) variant widely used for musical instruments like guitars, and the smaller 3.5 mm version for portable audio.^[80] RCA jacks, characterized by their phono connectors, handle unbalanced composite video and audio signals in consumer stereo systems.^[79] Power jacks, often barrel connectors with a central pin and outer sleeve, supply DC power to devices like laptops and chargers, typically featuring sleeve diameters of 5.5 mm or 3.5 mm and pin diameters of 2.1 mm or 1.3 mm. XLR jacks, with their three-pin configuration (pin 2 for positive signal, pin 3 for negative, and pin 1 for ground), enable balanced audio transmission for microphones and professional mixing consoles.^[81] Technical specifications vary by type and application, emphasizing signal integrity and compatibility. Phone jacks adhere to standards like TS (tip-sleeve) for mono unbalanced signals, TRS (tip-ring-sleeve) for stereo or balanced mono audio, and TRRS (tip-ring-ring-sleeve) for stereo with microphone input, commonly in 3.5 mm formats for headphones.^[82] Polarity in barrel power jacks is typically center-positive (sleeve at 0V, tip positive), though diagrams on devices confirm this to prevent damage, with voltage ratings supporting common DC levels from 5V to 20V depending on the adapter. XLR connectors maintain a 110-ohm impedance for balanced lines, reducing noise over long cable runs.^[79] In applications, electrical jacks are integral to consumer electronics, such as 3.5 mm headphone ports on smartphones and laptops for private audio playback.^[83] Professional audio setups rely on 1/4-inch TRS jacks for connecting instruments to amplifiers and XLR for microphones to mixers, ensuring low-noise signal paths in studios and live events.^[79] Telecommunications historically employed modular phone jacks, like RJ11 variants, for wired connections in landline systems and hands-free devices.^[84] The history of these connectors traces back to the 1870s with the advent of telephone switchboards, where Charles Scribner filed for a patent on the "spring jack" in 1878, issued as US Patent 293,198 in 1884, to enable efficient plug-based connections in early exchanges.^[78] By 1893, Scribner's designs (US Patent 489,570) closely resembled the modern 1/4-inch mono plug, initially featuring two conductors for switchboard operations.^[78] Miniaturization accelerated in the 20th century alongside portable devices, leading to the 3.5 mm standard for headphones by the mid-1900s and widespread adoption in consumer tech.^[80] Electrical jacks offer advantages in reliability for low-voltage signals, allowing quick, position-tolerant insertions that suit dynamic environments like live audio.^[85] However, issues such as loose connections from wear, temporary signal shorts during plugging (e.g., tip-to-ring contact in TRS), and grounding noise in unbalanced setups like TS or RCA can degrade performance.^[85] Balanced options like XLR mitigate noise but require compatible equipment.^[79]

References

[1]
Children's Activities - Toys - Fort Scott National Historic Site (U.S. ...
Oct 10, 2025 · Jacks - The game of jacks was played with small six-pronged objects called jackstones, or jacks. The first player started the game by throwing ...
[2]
Jack | Historic Jamestowne
### Summary of the Game of Jacks
[3]
Find of the Month: It's All Fun and Games! - Bar Yosef Family
Jan 2, 2017 · The origin of Knucklebones is probably a more primitive form of dice. Sophocles ascribed the invention of knucklebones to Palamedes, who taught ...
[4]
Ancient Greek and Roman Games Knucklebones
According to Sophocles, Knucklebones was invented by Palamedes, who taught it to Greek soldiers fighting in the Trojan War, although it probably came from Asia ...
[5]
Colonial Games (U.S. National Park Service)
Apr 25, 2025 · This game was played in early America as it had been played for over two thousand years, with small sheep knucklebones. The game was known as ...
[6]
How to Play Jacks (Knucklebones) - Official Game Rules
Equipment: A small rubber ball. A set of jacks (typically 10). Players ... Jacks Variations. Two-Handed: Players use both hands to pick up jacks. No ...Missing: children's | Show results with:children's
[7]
The Games > Jacks - Streetplay.com
Equipment includes 15 jacks and one small ball. Two players sit face to face; more than two sit in a circle. Deciding who goes first is optional, everything ...Missing: children's | Show results with:children's
[8]
Colonial Fun and Games - 18th Century Days - Holliston Historical ...
GENERAL RULES for Jacks. There are more than 100 different jacks games, but most follow these basic rules. Two or more people can play, indoors or out. To ...
[9]
[PDF] Law and Order on the Playground
For example, there are fifteen or more sub-games of jacks-" babies," pigs in the pen; eggs in the basket; around the world; rolling down Broadway; shooting ...
[10]
Jacks | How To Play The Game Of Jacks - Fun Games Kids Play
Place you hand on the ground straight and you have to place the jacks on the other side of the “fence” - ones through tens. Around the world. After you throw ...
[11]
Astragalos - Getty Museum
Jul 30, 2025 · One of the most popular toys among Greek children in antiquity was the astragalos, or knucklebone. Typically, the anklebone from the hind leg ...
[12]
28. Knucklebones — Portrait of a Plaything
Ancient Egypt, c. 1550-1458 BC ... These three knucklebones exhibited at the Met are more than 3500 years old, and were found during the museum's excavations of ...
[13]
Ancient Greek Adolescent Girls at Play [Sculpture]
It depicts two adolescent girls playing the game of "knucklebones" (astragaloi in Greek). The game was usually played like the modern game of "jacks": one ...
[14]
The Game of Five Stones or Knucklebones around the World
Jan 12, 2018 · The game of Five Stones is also known as Knucklebones. It's a time-honored game that was played in ancient Greece, Rome and even earlier.
[15]
A Game Worthy of the Ancients – Jacks - Heroes, Heroines, and History
Feb 12, 2024 · Another term from the Greek was Astragaloi, referring to a game of chance through divination. The sport was often utilized with real bones ...
[16]
Colonial Games Jacks
Starting: The game starts as described under the general rules, with one player tossing the ball and scattering the six jacks on the ground. Plastic Jacks.
[17]
Playing Games in the Great Outdoors
Jun 24, 2019 · Jacks, also called jackstones, fivestones, or dibs, is one of the oldest and most widespread games in the world. Children in ancient Egypt ...
[18]
Jacks - The Strong National Museum of Play
Jacks is one of the oldest and most widespread games in the world. All jacks games share a strategy: toss a ball in the air and scoop up pieces before the ball ...
[19]
Jack and Jill Went Up the Hill - Nursery Rhyme by Mother Goose
Jack and Jill went up the hill, To fetch a pail of water; Jack fell down, and broke his crown. And Jill came tumbling after.
[20]
Goldilocks and the Three Dinosaurs Jacks Game - The OT Toolbox
Nov 14, 2016 · Playing jacks requires the hands to move in response to what is perceived and is a challenge to eye-hand coordination skills. Try using the ...
[21]
Gonggi Nori - 한국민속대백과사전
There is also a similar game in the West called “Jacks, ” or Knucklebones. Since finding the necessary items is relatively easy, it is estimated that this game ...
[22]
Gambling in Ancient Times - ancientgames.org
May 28, 2025 · Senet, dating back to around 3000 BC in Egypt, evolved from a simple board game to one with religious significance. There is evidence suggesting ...
[23]
Brian Jacks Judoka - JudoInside.com
British judoka Brian Jacks is the 1972 Olympic bronze medallist. He also took the bronze medal at the 1967 World Championships in Salt Lake.
[24]
Brian Jacks | Team GB
British judoka Brian Jacks won bronze at the 1972 Munich Olympics. It was his only medal in three appearances at the Games but it was perhaps on BBC TV Show ...
[25]
Magician, superstar and raconteur – the curious life of judoka Brian ...
May 22, 2018 · Within three years, he had become Britain's first World Championship medalist, adding an Olympic bronze in 1972. That success is impressive ...
[26]
https://www.11v11.com/teams/millwall/tab/players/season/1970/
[27]
All Millwall football club players: 1970
Eamonn Dunphy, Midfielder. Ronnie Howell, Midfielder. George Jacks, Midfielder. Ken Jones, Midfielder. Bryan King, Goalkeeper. Barry Kitchener, Central defender.
[28]
Ronald Jacks - Team Canada - Official Olympic Team Website
Sport: Swimming. Games: Munich 1972, Mexico City 1968, Tokyo 1964. Born: January 23, 1948. Height: 180cm. Weight: 80kg. Birthplace: Winnipeg, Manitoba.
[29]
Ron Jacks - Olympedia
Results ; 4 × 100 metres Medley Relay, Men (Olympic), Canada ; 1968 Summer Olympics · Swimming (Aquatics), CAN ; 400 metres Freestyle, Men (Olympic) ; 4 × 200 ...
[30]
Ron Jacks - BC Sports Hall of Fame
He would also join the Canadian team for the 1968 Mexico City Olympics and the 1972 Munich Olympics. In April of 1966, after training in California under ...
[31]
Sam Jacks - Ringette Canada
In 1963, Jacks was elected President of the Society of Directors of Municipal Recreation of Ontario. He designed the Society's coat of arms, was a major ...
[32]
Ron JACKS | Results | World Aquatics Official
Personal Best Results ; Men 200 Freestyle, 02:02.10, - ; Men 100 Freestyle, 01:01.35, - ; Men 400 Freestyle, 04:16.08, - ; Men 1500 Freestyle, 17:07.57, - ...Missing: Canadian | Show results with:Canadian
[33]
Will Jacks Profile - Cricket Player England | Stats, Records, Video
Born. November 21, 1998, Chertsey, Surrey ; Age. 26y 356d ; Batting Style. Right hand Bat ; Bowling Style. Right arm Offbreak ; Playing Role. Batting Allrounder.Matches · Stats · Records · Photos
[34]
Will Jacks - ECB
Fixtures, England Men, England Women, England Disability, Rothesay County Championship, Vitality Blast Men, Vitality Blast Women, Metro Bank One Day Cup Men.
[35]
Will Jacks - Kia Oval
Birthdate 21/11/1998 · Nationality English · Height 6'1 · Role All-Rounder · Batting Right Hand Bat · Bowling Right Arm Off Spin · Debut Somerset, 2018.
[36]
Al Jacks (1989) - Clarion University Sports Hall of Fame
Al Jacks ... The name synonymous with Clarion University's football tradition, AI Jacks was head coach of the Golden Eagles from 1963 to 1981 (19 seasons). Piling ...
[37]
Obituary information for Albert A. Jacks Jr. - Goble Funeral Home
Feb 16, 2023 · As head coach for 19 seasons, “Al Jacks” became synonymous with Clarion's football tradition and was Clarion's winningest football coach with a ...
[38]
In Loving Memory: Coach Al Jacks - Clarion Athletics
Feb 16, 2023 · He was 87 years old. "This is a sad day for our Golden Eagle family as we say good-bye to Al Jacks," said Clarion athletic director Dr.
[39]
Jim Jacks dead at 66; produced The Mummy - Variety
Jan 20, 2014 · Jacks' first credit came as an executive producer on “Raising Arizona” in 1987 and he went on to work on the Coen brothers' “Barton Fink,” “ ...
[40]
Jacks, Lawrence Pearsall - Dictionary of Unitarian & Universalist ...
Jul 23, 2003 · Lawrence Pearsall Jacks (October 9, 1860-February 17, 1955), or L. P. Jacks ... Hibbert Journal, which he served from its foundation in 1902 until ...
[41]
Robert Jacks | British Museum
Biography: Australian painter, draughtsman, printmaker and sculptor; born 8 March 1943 in Melbourne; studied sculpture at Prahran Technical College, ...
[42]
Susan Jacks
### Biography of Susan Jacks
[43]
Terry Jacks
### Biography of Terry Jacks
[44]
Tyler Jacks | Koch Institute
From 2001-2021, Professor Jacks served as director of the MIT Center for Cancer Research and its successor, the Koch Institute. ... Jacks received the American ...Tyler Jacks, Phd · Research Summary · Research Areas
[45]
https://garagehangover.com/jacks/
[46]
Jacks
### Summary of Jacks (Japanese Psychedelic Band)
[47]
Jacks | Garage Hangover
Oct 18, 2009 · By June of 1967 they had became a quartet with Hitoshi Tanino playing bass and Takasuke Kida on drums. Takahashi soon left the group so Haruo ...Missing: 1970s | Show results with:1970s
[48]
Vacant World | Jacks
Free deliveryIncludes a full-color booklet with photos and an essay by esteemed rock writer Manabu Yuasa (in both Japanese and English). ... Vinyl only release, no digital.Missing: 1960s | Show results with:1960s
[49]
JACKS discography and reviews - Prog Archives
JACKS was a Japanese psychedelic/space rock band formed in 1967, starting as a folk band, and released two albums before disbanding in 1969.Missing: 1970s | Show results with:1970s
[50]
AXS EXCLUSIVE: 5 THINGS YOU NEED TO KNOW ABOUT THE ...
Feb 19, 2019 · The band is comprised of Jonny Stanback (vocals/guitar), Tom Hunter (guitar/vocals), Scott Stone (bass/vocals), and Josh Roossin (drums).Missing: Los Angeles Blood
[51]
Heart, Soul, & Ignition: The Jacks' 'Remember You' EP Is Pure 21st ...
Mar 31, 2020 · The Jacks' 'Remember You' EP is 21st Century indie rock at its finest. Get to know the exciting Los Angeles band and dive into the heart, soul, and feverish ...Missing: Blood | Show results with:Blood
[52]
The Jacks Announce New EP, 'Remember You' In March
Jan 23, 2020 · Los Angeles quartet The Jacks have announced the release of their second EP, 'Remember You', which is set for release through EDGEOUT Records/UMe on 6 March.<|separator|>
[53]
THE JACKS: Slowdance Album - EDGEOUT Records
Sep 16, 2021 · Today Orange Country-based pop-rock band THE JACKS have released their debut full-length album, Slowdance (order/stream).
[54]
The Jacks: Album review - upstart
Sep 9, 2010 · The Jacks, a three piece band from Melbourne, is a mix between punk and rockabilly. Renee Tibbs reviews their self-titled album which, ...
[55]
Tracy Jacks by Blur - Songfacts
Originally titled "Tracey Jacks," this song was reportedly influenced by another "name song": "David Watts" by The Kinks, which was covered by The Jam in 1978.
[56]
Sometimes Jacks Rule the Realm - song and lyrics by 311 - Spotify
Listen to Sometimes Jacks Rule the Realm on Spotify. Song · 311 · 2003.
[57]
Big L – Ebonics Lyrics - Genius
Money is "chips", movies is "flicks" Also, "cribs" is homes, "jacks" is payphones. Cocaine is "nose candy", cigarettes is "bones" Uh, a radio is a "box", a ...
[58]
jack ⋅ definition & examples from rap lyrics ⋅ the Right Rhymes ...
Come to find out that bitches are pullin jacks. 1994-02-01 E.S.G. "Crooked Streets" feat. Big 50 [Ocean of Funk]. Hitting licks and cooking kis, pulling major ...
[59]
The 19th Century plug that's still being used - BBC News
Jan 11, 2016 · The 3.5mm headphone jack is essentially a 19th Century bit of kit - it is a miniaturised version of the classic quarter-inch jack (6.35mm), which is said to go ...
[60]
A Short History of the Nearly Obsolete 1/8 Inch Headphone Jack
Sep 13, 2016 · The roots of 3.5mm audio cables are found not in pro-audio or early music technology, but in the earliest era of telecommunications.
[61]
The Cohutta Wilderness - Georgia Mountains - Sherpa Guides
The Cohutta Wilderness. The Cohutta Wilderness covers 36977 acres (about 60 square miles) that spill over the Georgia/Tennessee border and lie within the ...
[62]
Jacks River - Jones Mill/Bethlehem Church to Conasauga Confluence
Aug 29, 2023 · The top portion of Jacks River Falls is doable in high water although class V in high water. It empties into a beautiful pool about 40 feet ...
[63]
[PDF] Conasauga Logperch Five-Year Review: Summary and Evaluation
Aug 5, 1985 · Recent surveys have expanded the species' known range to include additional reaches of the Conasauga. River mainstem and the Jacks River near ...
[64]
[PDF] FOREST SERVICE HANDBOOK NATIONAL HEADQUARTERS (WO ...
... Cohutta Wilderness Area--Proposed" and shall be known as the Cohutta Wilderness. (16 U.S.C. 1132(note)). Designation of Wilderness Study Areas. Sec. 4. (a) In ...
[65]
Rivers Alive - Georgia.gov
Rivers Alive is Georgia's annual volunteer waterway cleanup event that targets all waterways in the State including streams, rivers, lakes, beaches, ...About Rivers Alive · Forms and Documents · Contact Us · Organize a Cleanup
[66]
Mechanical Jacks - Types & Applications | Metro Hydraulic Jack Co.
Here are three common types of mechanical jacks and how each is used. Screw Jacks. Screw jacks utilize a screw mechanism to raise and lower the load. The ...
[67]
Hydraulic Jacks: What They Are, How They Work, and Applications
Oct 10, 2025 · Other Types of Jacks · Toe Lift Hydraulic Jacks · Leveling Jacks · Scissor Jacks · Screw Jacks · Ratchet Jacks.
[68]
14+ Types Of Jacks & Their Uses | Hawk Lifting
Mar 3, 2023 · 14 types of jacks you need to know · Trolley Jack · Pallet Jack · Pneumatic Jack · Floor Jacks · Transmission Jacks · Screw Jacks · Ratchet Jacks.
[69]
How does a hydraulic jack work: Pascals law - tec-science
Jul 22, 2019 · A hydraulic jack is based on Pascal's law, which states that the pressure in liquids acts equally in all directions.
[70]
Hydraulic Jacks 101: A Guide to Their Function and Uses
Jun 12, 2023 · Hydraulic jacks are essential for lifting heavy loads, making them indispensable for various industries such as automotive, construction, and manufacturing.
[71]
What is an Elevator Jack, and How Does It Work?
Jan 10, 2025 · An elevator jack is a piston-like device in hydraulic elevators that applies the necessary force to lift and lower the elevator car.
[72]
Artifact of the Month: Need a Lift? | Queen Anne's Revenge Project
Jan 1, 2018 · 17th and 18th century jacks were designed to lift or pry apart heavy objects. Described in mechanical and shipbuilding treatises, depicted on trade cards.
[73]
Richard dudgeon - US8203A - Google Patents
What I claim as my invention and desire to secure by Letters Patent is- An hydraulic press `quite portable in which the ram is hollow and serves as the ...
[74]
https://patents.google.com/patent/US8203A/en
[75]
Hydraulic jack: Safe lifting? Key steps here - Tomac Tools
Aug 14, 2025 · Select a jack with 25–30% greater capacity than the expected load. OSHA (2023) reports that 37% of failures stem from overloading, often due to ...
[76]
Quick Safety Tips for Using Heavy-Duty Jacks - Duff-Norton Air Jacks
Nov 12, 2024 · Ensure the jack stands on a flat, solid surface. Pump the handle smoothly to raise the load, and never exceed the jack's specified weight limit.
[77]
Ancient History Of The Phone Jack | Hackaday
Jun 5, 2020 · Turns out the venerable plug goes back to at least 1878. Keep in mind, I'm talking about the good old fashioned 1/4′′ phone jack with two wires.
[78]
Cable Buying Guide - InSync - Sweetwater
There are six cable connectors you'll come across frequently: TRS and XLR for balanced connections and TS, RCA, speakON, and banana plugs for unbalanced ...
[79]
A Guide To Jack Plug Sizes and Cables - Maplin
Mar 7, 2024 · Jack cables come in various connector sizes, commonly referred to as "jacks". The most commonly used jack plug sizes are 1/4 inch (6.35mm) and 3.5mm.
[80]
https://www.maplin.co.uk/blogs/expert-advice/a-guide-to-jack-cables-and-plugs
[81]
TS and TRS, oh and TRRS
### Summary of TS, TRS, and TRRS Standards for Audio Jacks
[82]
Headphone Jacks and Plugs: Everything You Need to Know
Jan 29, 2024 · Common Usage: TS connectors are mainly used with guitars, instruments, and mono audio applications that do not require a long cable connection.Types Of Headphone Jacks And... · 3-Conductor Plug (trs) · 4-Conductor Plug (trrs)
[83]
Phone Jacks and Plugs Selection Guide - GlobalSpec
Phone jacks and plugs are connectors used with telephones and other audio systems. They are also known as modular jacks (female) and modular plugs (male).
[84]
Jack connectors and their future in the 21st century - TME.eu.
Apr 30, 2021 · Jack connectors are likely to disappear completely from mobile phones, but they will continue to be used in professional audio equipment and industry.