# Harrow > Teeth dragged over ploughed ground to break the clods - Date: c. 2,400 BCE - Era: Antiquity - Domain: [Agriculture & Livestock](https://lastcodex.org/en/domains/agriculture/) - Rebuild stage: II (Settlement) - Difficulty: 1/5 - URL: https://lastcodex.org/en/inventions/harrow/ A harrow is a frame set with teeth, or a bundle of branches, dragged over ploughed ground. It breaks the clods into fine soil, levels the ridges and covers the seed. Sumerian administrative texts of about 2400 BCE already record fields harrowed several times after ploughing. ![Harrow · Teeth dragged over ploughed ground to break the clods](https://lastcodex.org/_astro/plate.BEz_1K3A_Z1ggdqK.webp) ## Legend 1. Wooden beams running in the direction of pull 2. Cross bars 3. Iron tines 4. Front hook and draught chain 5. Swingletree joined to the traces ## What it is A [plough](/en/inventions/plough/) leaves the field rough, with slices and lumps of earth and hollows between them. Seed sown on such ground falls unevenly, and much of it stays uncovered or ends up too deep. The harrow is the tool that comes next. It is dragged over the ploughed ground to break the clods, fill the hollows and leave a fine, level layer of soil in which seed can be sown at an even depth. ![A bundle of thorny branches spread like a fan and tied to a wooden cross bar, with a rope at both ends, lying on ploughed earth that is smooth where it has already passed](https://lastcodex.org/_astro/v1.C1hLXDiw_7Edrv.webp) _A brush harrow: thorny branches tied to a bar smooth the soil as they are dragged._ The oldest kinds need no smith. A bundle of thorny branches tied to a bar, or a wicker hurdle, smooths and crumbles the surface as it slides. A toothed harrow does more. It is a frame of wooden beams set with teeth, called tines, of hard wood or iron, which dig into the soil as the frame is pulled. In England such frames were still in use in the nineteenth century. One kept by the Museum of English Rural Life has four parallel beams, three cross bars and twenty pointed iron tines curved slightly forward. A team of oxen or a horse pulls it on a chain hooked to the front. ## How it works The tines work like the fingers of a hand dragged through sand. Each one meets clods, splits them and rolls the pieces aside, while the frame scrapes the tops off the ridges and pushes loose earth into the furrows. Tines that follow one another in the same groove add little, so harrow makers spread them across the width. Wang Zhen's square harrow has its teeth set alternately on two beams that lie across the line of pull, the teeth of the rear beam passing between those of the front one, and the iron harrows of the nineteenth century carried their tines in zigzag rows so that each followed its own track. A second pass at right angles to the first finishes the work. ![A long rectangular wooden frame seen from above on smooth earth: two beams joined by short end pieces, with thin cross sticks between them and withies woven over and under the sticks; it has no teeth](https://lastcodex.org/_astro/v3.Dk1BJ6mZ_Z20pnfy.webp) _The lao, a toothless frame with withies woven between its bars, rubs the soil smooth._ A light harrow rides over hard clods without biting. Weight makes the tines go deeper: Chinese farmers stood on the harrow, according to Wang Zhen in 1313, and at the end of each run lifted their feet for a moment to let the weeds and roots caught in the tines drop off. Stones laid on the frame do the same job. A toothless harrow does something else. Wang Zhen describes the lao, a frame with withies woven between its bars, which rubs the soil smooth after the toothed harrow. Pressing the surface shut keeps the moisture in, and a sixth-century Chinese manual warns that ground left open in the spring wind dries out. After sowing, a harrow drawn once more covers the seed with earth, and Jethro Tull's [seed drill](/en/inventions/seed-drill/) of 1701 carried a small harrow behind it for that purpose. On a young crop, a light pass with iron teeth pulls out seedling weeds, whose roots are still shallow, while the deeper-rooted grain stays in place. ## How to do it A small hand harrow is enough to prepare a vegetable bed after digging. Cut three battens of hardwood of the same length and two shorter pieces to serve as cross bars. Mark the battens for the tines so that those of the middle batten fall halfway between those of the two outer ones. Drill the holes slightly smaller than the hardwood dowels you will use as tines, then drive the dowels through with a little glue, pointed end down, leaving about a finger's length below the wood. Lay the three battens parallel, one behind the other, tines down, and fix the two cross bars over them with wooden pegs or screws. Tie a rope to the two ends of the front batten so that it forms a loop, and pull from the middle of the loop: the harrow then runs straight, the battens lie across the direction of travel, and the tines of the middle batten pass between those of the other two. Use it on dug soil that is moist but crumbles, never on sticky wet ground. Drag it slowly along the bed, then across, and put a flat stone on the frame if the clods are hard. A bundle of twiggy branches tied to a bar makes a brush harrow for the last, smoothing pass. Safety. Clamp the wood before sawing or drilling and keep your hands away from the blade and bit. Pointed tines can injure: store the harrow upright against a wall, tines facing the wall, never lying tines up on the ground. Wear gloves to handle thorny branches. A full-size harrow behind an animal or a tractor is a dangerous machine: never ride on one, never walk in front of it, and leave that work to people trained with the team or the tractor. ## History and evolution The oldest written evidence of harrowing comes from Sumer. Administrative texts from Girsu, in the state of Lagash, written in the Early Dynastic period around 2400 BCE, have words for land that was ploughed, harrowed, or both, and record fields gone over several times with a harrow after the harvest, as Daniel Potts sums them up. The Sumerian dictionary of the University of Pennsylvania lists the word for harrow, ganur, in texts of that period and of the following Akkadian and Ur III periods. Some centuries later, the Farmer's Instructions, a manual preserved on tablets from Nippur and Ur of the Old Babylonian period, about 1900 to 1600 BCE, tells the farmer to work his field with three kinds of plough and then to harrow it once, twice, three times. A Sumerian work song of the ploughing oxen calls the harrow "the comb of my field" and asks for it to be fitted with large teeth, and word lists of the Old Babylonian period name the tooth and the shaft of a harrow. Roman writers knew both kinds. Varro, in the first century BCE, describes the irpex as a bar with many teeth that oxen drag like a cart to tear out what creeps in the soil, and Virgil praises the farmer who drags wicker hurdles over his field. Pliny the Elder notes that the clods are broken with a harrow or a heavy rake, that the seed is then covered with a toothed harrow or a plank tied behind the plough, and that rank young crops are combed with a harrow armed with iron teeth. In China, the sixth-century manual Qimin yaoshu by Jia Sixie has the farmer pass an iron-toothed harrow twice over newly cleared land and then smooth it with the lao, and quotes a proverb that ploughing without smoothing does more harm than good. Wang Zhen's agricultural treatise of 1313 draws a square harrow whose two beams are pierced with staggered square holes for wooden teeth, a V-shaped harrow with cast iron teeth, and the toothless lao, and quotes an older rule: plough once, harrow six times. In Europe, the Bayeux Tapestry, embroidered in the late eleventh century, shows in its border a horse wearing a [collar](/en/inventions/horse-collar/) and drawing a harrow. Wooden frames set with iron tines stayed in use for centuries. The Museum of English Rural Life keeps one made around 1850 at Hailey, in Oxfordshire, and used to break the surface of the soil before sowing. ![A gang of six dished steel discs on one square axle in an iron frame, set at an angle to the direction of travel, each disc cutting the soil and throwing it to its hollow side, with a scraper above each disc](https://lastcodex.org/_astro/v2.CPkkgNCv_ZnYOFa.webp) _A disc harrow gang: set at an angle, the dished discs cut the clods and throw the soil sideways._ The nineteenth century brought iron. Iron frames carried tines in zigzag rows so that each one followed its own track, and steel replaced the wrought or cast iron teeth that often snapped. Spring teeth, which bend and spring back when they hit a stone, followed. In the United States, Silas Moody patented in 1866 a sod cutter with a row of flat circular blades on an axle, and Frederick Nishwitz in 1869 a revolving harrow with dished discs whose angle could be adjusted. Such machines needed thin, hard blades that did not shatter on stones, and they spread as cheap [steel](/en/inventions/steel/) became available after the middle of the century; disc harrows began to appear on American farms in the 1870s. In 1885 Henry Rose of Sandwich, Illinois, patented gangs of discs that could change their angle to the line of draught. Set at an angle, the discs slice the ground and throw it sideways, which breaks clods and buries stubble in a single pass. ## Key facts - Oldest mention: Sumerian administrative texts from Girsu, about 2400 BCE - Roman toothed harrow: The irpex, a bar with many teeth drawn by oxen (Varro, 1st century BCE) - Chinese rule quoted by Wang Zhen in 1313: Plough once, harrow six times - Disc harrow: United States, from the late 1860s ## Requires - [Plough](https://lastcodex.org/en/inventions/plough/): Opening the soil for seed (c. 5,000 BCE) ## Sources - [ganur [harrow], attested in Early Dynastic IIIb, Old Akkadian, Ur III and later texts](https://oracc2.museum.upenn.edu/epsd2/cbd/sux/o0155602.html), Electronic Pennsylvania Sumerian Dictionary (ePSD2), University of Pennsylvania - [Mesopotamian Civilization: The Material Foundations (1997), chapter III, Agriculture and Diet, pp. 78–86](https://uruk-warka.dk/news/2023/Mesopotamian_Civilization_The_material_f.pdf), Daniel T. Potts, Cornell University Press / Athlone Press - [The farmer's instructions (c.5.6.3), translation](https://etcsl.orinst.ox.ac.uk/section5/tr563.htm), The Electronic Text Corpus of Sumerian Literature, University of Oxford - [The song of the ploughing oxen (c.5.5.5), translation](https://etcsl.orinst.ox.ac.uk/section5/tr555.htm), The Electronic Text Corpus of Sumerian Literature, University of Oxford - [CDLI Literary 000784 (Farmer's Instructions), ex. 002, Nippur, Old Babylonian period (ca. 1900–1600 BC)](https://cdli.earth/artifacts/268912), Cuneiform Digital Library Initiative - [The First Farmer's Almanac, from History Begins at Sumer (1956)](https://www.hort.purdue.edu/NEWCROP/Hort_306/reading/Reading%209-3.pdf), Samuel Noah Kramer, reading for HORT 306, Purdue University - [Old Babylonian lexical list P253863: ŋešgana₂-ur₃ "harrow", tooth and shaft of a harrow](https://oracc.museum.upenn.edu/dcclt/P253863), Digital Corpus of Cuneiform Lexical Texts (DCCLT), Oracc - [Varro, De lingua Latina 5.136 (irpices)](https://www.thelatinlibrary.com/varro.ll5.html), The Latin Library - [Pliny the Elder, The Natural History, book 18, chapters 48–50, translated by John Bostock and H. T. Riley](https://gutenberg.org/cache/epub/61113/pg61113-images.html), Project Gutenberg - [Crates, in A Dictionary of Greek and Roman Antiquities (1875)](https://penelope.uchicago.edu/Thayer/E/Roman/Texts/secondary/SMIGRA*/Crates.html), William Smith, LacusCurtius, University of Chicago - [Qimin yaoshu (6th century), book 1, on ploughing and harrowing](https://zh.wikisource.org/wiki/%E9%BD%8A%E6%B0%91%E8%A6%81%E8%A1%93/%E5%8D%B7%E7%AC%AC%E4%B8%80), Jia Sixie, Chinese Wikisource - [Nong shu (1313), Nongqi tupu: the harrow (pa) and the toothless harrow (lao)](https://zh.wikisource.org/wiki/%E7%8E%8B%E7%A6%8E%E8%BE%B2%E6%9B%B8/%E5%8D%B7%E5%8D%81%E4%BA%8C), Wang Zhen, Chinese Wikisource - [Harrow, Encyclopædia Britannica, 11th edition (1911), vol. 13](https://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica/Harrow), Wikisource - [Harrow, object 52/374](https://reading.ac.uk/adlib/Details/collect/1354), Museum of English Rural Life, University of Reading - [Harrow (drag), Hailey, Oxfordshire, c. 1850, object 52/335](https://reading.ac.uk/adlib/Details/collect/1353), Museum of English Rural Life, University of Reading - [The History of the Harrow](https://www.farmcollector.com/looking-back/history-of-the-harrow-zb0z1703zhur/), Sam Moore, Farm Collector (2017) - [He Saw the Disc Harrow Tried](https://www.farmcollector.com/looking-back/he-saw-the-disc-harrow-tried-zb0z2507/), Sam Moore, Farm Collector - [Patent model of Henry Rose's disc harrow (1885)](https://www.museum.state.il.us/OHIA/htmls/technology/patent_models/tech_pat_rose85disk.html), Illinois State Museum - [The Bayeux Tapestry through the ages (2016)](https://ia800509.us.archive.org/31/items/bayeux-tapestry/bayeux-tapestry.pdf), Marie Lebert, Internet Archive - [Agricultural Revolution: the new horse collar (drawings from the Bayeux Tapestry)](https://www.depts.ttu.edu/history/AffiliatedPrograms/jhowe/images/Agricultural_Revolution_new_horse_collar.php), John Howe, Department of History, Texas Tech University Fact-checked on 2026-10-17. --- The Last Codex · https://lastcodex.org/en/inventions/harrow/ · © The Last Codex. Texts, plates and figures: CC BY-NC-ND 4.0.