Former employees of the company, OceanGate, said they worried about its practices long before a fatal implosion that killed five people. A Coast Guard hearing resumes on Tuesday.

By 1500, towns remained small throughout Europe. These days, a populated area with up to twenty thousand inhabitants is recognised as a small town or large village; France had only fourteen towns larger than that, and England had just one, London. The contrast between urban and rural life is illustrated well by some of the most remarkable frescoes from before the Renaissance, painted by Ambrogio Lorenzetti in the Palazzo Pubblico in Siena in 1338-39.

These frescoes for the Council Room are overt social and political commentary forming a lesson in civics. In six different scenes, he shows allegories and examples of good and bad government in the city and country. The Effects of Good Government in the City (1338-39) is modelled after Siena, and intended to illustrate peaceful prosperity resulting from wise politics. There are no beggars, no street crime. Life is peaceful and orderly, and the citizens are prosperous and healthy. During its golden age before the Black Death in 1348, Siena reached a population of fifty thousand, huge by the standards of the day, and similar to its present size.

Essential to the prosperity of the city were the Effects of Good Government in the Countryside (1338-39), where crops were grown and livestock farmed to feed the city and provide materials for its trade. This is a neat, almost manicured countryside with a patchwork of fields, and all the peasants fully occupied and working hard.

Almost all farms combined the rearing of livestock such as cattle with the production of cereals and vegetables, and few were able to specialise in either, or in a single crop. Almost all had the joint tasks of feeding locals at a subsistence level and trying to grow a surplus to sell into the city.

Key to the growing of crops was soil quality. The only fertiliser available to increase soil nutrients came from livestock, and the only way to prepare the soil to give the best yields was ploughing. Little land at this time had any form of drainage, so in many parts of Europe it was wet for much of the year. That made the soil heavy, particularly if it was clay, and ploughing was used to break the soil up into a fine tilth, and to build that into ridges and furrows to help it drain.

This is shown in the foreground of this copy, possibly painted by de Momper, of Brueghel’s Landscape with the Fall of Icarus from about 1558. Although its landscape is fictitious, the ploughman in the foreground appears true to life, and his plough typical of much of Europe at that time, as shown in the detail below.

At the very front of the plough is a small jockey wheel, behind which is a vertical metal blade, the coulter or skeith, whose task is to cut into the ground just ahead of the share, a wooden board that turns the surface of the earth to one side. The effect on the ground is to cut furrows into its surface and turn the soil onto ridges. When repeated five or more times over the course of the autumn and winter, this could build ridges high enough for the water to drain into the furrows, and coupled with the action of ground frost could break up even heavy clays into a tilth ready for sowing in the Spring.

An interesting detail revealed in Brueghel’s painting is how the course of the plough is curved, and swings wide to make the turn, as I explained in the introduction to this series last week.

Ploughing required considerable pulling power, usually delivered by a team of oxen, generally bullocks (castrated males), rather than horses. Where the soil was heavy going, a team of six or even eight were required. Even after the introduction of the heavy mould-board or turning plough in the eighteenth century, it wasn’t unusual to see large teams still in use.

Rosa Bonheur’s Ploughing in Nevers, painted in 1849, shows two teams of six oxen each drawing more modern mould-board ploughs through heavy soil to build high ridges.

Further improvements in plough design and possibly lighter soil enabled the reduced team seen in Eugène Burnand’s Ploughing in the Jorat in 1916, with a single horse leading a pair of oxen.

By 1931, when Grant Wood painted Fall Plowing, the recently-developed walking plough had a steel ploughshare, bringing a major advance in cultivating the prairie in Iowa. By this time many farms had started to replace their horses and oxen with tractors, a subject I’ll return to later in this series.

Ploughing was arduous work for all concerned, and working even relatively small areas of arable land was time-consuming. In more northerly latitudes, winter days are short, and it wasn’t easy to find sufficient daylight to plough enough land five times over for the following year’s crops. Arable farming demanded a great deal of time and effort year-round.

In the first of these two articles showing paintings of the horse in narrative, I showed examples from classical myths and legends, culminating in that of Saint George and the dragon. This leads to the role of the horse in chivalry, with its origins in the crusades.

The crusades presented Carl Friedrich Lessing with an ideal combination of mediaeval history, romance, and chivalry. In The Return of the Crusader from 1835, he shows a lone knight in full armour dozing as his horse plods its way up a path from the coast. Although his armour is still shiny, a tattered battle pennant hangs limply from his lance. This is based on a Romantic poem by the writer Karl Leberecht Immermann (1796-1840).

Walter Crane is one of the earlier artists to depict a late fifteenth century poem revived in a ballad from 1819 by John Keats. The Belle Dame Sans Merci is shown riding side-saddle on the knight’s horse, flowers in her long, flowing tresses, as the knight, clad in armour and heraldic overgarments, holds her hand.

The same year that Keats wrote his ballad, Lord Byron wrote his poetic account of the legendary Mazeppa, who was bound naked to a wild horse and set loose as punishment for his affair with a Polish Countess.

Horace Vernet’s Mazeppa and the Wolves from 1826 shows the young victim during his wild ride that took him to the point of death before he was rescued.

Mykola Samokish’s watercolour of a Ukrainian Cossack on a Horse, or Haidamak on a Horse from 1899 shows a haidamaka, a Ukrainian insurgent who took part in uprisings against the ruling Polish Empire that governed west Ukraine in the eighteenth century. They were immortalised in an epic poem in 1841 by the father of Ukrainian literature Taras Shevchenko.

Horses are a longstanding feature of circuses, and individual showmen and women around the world.

Georges Seurat’s The Circus from 1891 is one of the masterpieces of Divisionism, and may depict a scene in the Cirque Fernando of Montmartre in Paris. Its internal contradiction is the artist’s choice of a painstakingly slow and mechanical method of painting, for a motif that is full of spontaneous movement and action.

In the millennia before the arrival of steam engines, horses were the fastest means of travel, and inevitably were used in racing.

In February 1817, Théodore Géricault witnessed the Roman Carnival, with its traditional horse race. Among the studies that he made of that event is Race of the Barberi Horses (1817), intended for a later large studio painting that he never started. This was a longstanding tradition of the Roman Carnival, where these horses were gathered in the Piazza del Popolo, then raced without riders to gallop down the Corso to be recaptured at the finish. The Barberi are a hardy North African breed popular among the Berbers, and are still bred today although this race has long since ceased.

More orderly horseraces have been popular events.

Géricault’s The Epsom Derby from 1821 follows the convention of the day in showing galloping racehorses flying through the air, legs in full extension, without contact with the ground beneath them. It wasn’t until early photographic studies demonstrated that this never occurred in real life that artists reluctantly changed their images.

The Derby Stakes is a flat-race that has been run on Epsom Downs, to the south of London, since 1780. At this time it was run on a Thursday in late May or early June, despite the unseasonal weather seen here. It was accompanied by a large fair, the subject of a later painting by William Powell Frith in 1858. I suspect that Géricault’s version was a significant influence on the later equestrian paintings of Edgar Degas.

The New World of the Americas grew their own stories about feats achieved by horses and their riders.

Grant Wood’s Midnight Ride of Paul Revere (1931) was inspired by Longfellow’s poem Paul Revere’s Ride (1860), telling of the American patriot Paul Revere (1735-1818) and his midnight ride on 18 April 1775, to alert colonial militia of the approach of British forces before the battles of Lexington and Concord. This is shown using a bird’s eye view giving it an air of unreality.

My last two paintings are even more unreal.

Long before Courbet’s well-known allegorical painting of his studio, Horace Vernet painted his as being just as crowded, rich in stories, and puzzling. In the centre, two young men fight one another with swords by a white horse, which is tethered to the wall. Immediately in front of the white horse is a pair of boxers, and another young man sits on the back of a chair to watch the fencing, holding a rifle against the left side of his body.

In the left background a couple of pupils are actually engaged in painting at easels, but the most prominent easel in the room is completely ignored by those present. Another painter is at work at the far left, apparently talking with three young men who are watching, and accompanied by a drummer. Another small group of young men is engaged in discussion against the wall to the left.

Henry Fuseli’s breakthrough painting of his career, The Nightmare from 1781 was exhibited the following year at the Royal Academy, and remains the work by which he is best known. It shows a daemonic incubus squatting on the torso of a young woman, who is laid out as if in a deep sleep in bed, her head thrown back, and her arms above her head. Lurking in the darkness to the left is the head of a black horse, whose eyes appear unseeing. The incubus stares directly at the viewer in a manner which arouses discomfort.

As we near the end of this alphabet of landscape painting, this week we reach the letter y, standing for yellow, one of the most important and versatile colours in the artist’s palette. It’s most strongly associated with late summer, when much of the countryside has become dry and turned from the green of Spring to the yellows of ripened grain, ready for harvest.

Perhaps the earliest complete visual reference to the grain harvest is Pieter Bruegel the Elder’s The Harvesters from 1565. This shows each step in the traditional and labour-intensive processes of cutting the ripe crop, gathering it into stooks, transporting it by cart for threshing, and onward transfer of grain to the waiting ships in the far distance.

In 1826, the young British painter Samuel Palmer moved to the rural village of Shoreham in Kent, in the valley of the River Darent to the north of Sevenoaks, where he spent much of the next decade producing some of his most distinctive work. For Palmer, the village and its environs became his ‘land of milk and honey’, in a Biblical vision of Beulah. His finely-detailed Oak Trees, Lullingstone Park was painted two years later, in 1828. This shows ancient oaks in the deer park of Lullingstone Castle, in the Darent Valley of Kent, between Eynsford and Shoreham, with their leaves turned yellow in the early autumn.

Towards the end of his time in Shoreham, Palmer’s views started to open out into more conventional landscapes, such as The Golden Valley (c 1833-34), caught here at the end of the harvest.

Painted three centuries after Pieter Bruegel the Elder’s encyclopaedic account, Charles-François Daubigny’s Harvest from 1851 is remarkably similar, although its yellows are more muted.

Further afield, in the vast cereal-growing lands of Ukraine, Volodymyr Orlovsky’s Harvest in Ukraine (1880) shows laborious hand-cutting of grain on the steppe, and demonstrates the origin of the Ukrainian flag of blue and yellow.

Mykola Pymonenko’s classic view of Harvest in Ukraine from 1896 follows a compositional formula developed by Jules Bastien-Lepage for Naturalist paintings. Its horizon is high, about three-quarters of the way up the canvas. The women in the foreground and the child’s cradle are painted in fine detail, and their edges are so crisp that they pop out. As the figures and fields recede into the background, they rapidly lose detail and their edges blur. The effect is of a vivid reality at the focus of the image, with deep recession to the distant horizon.

Camille Pissarro started work on his intensely sensory and idyllic painting The Gleaners in early 1888, using a squared-up study in gouache to finalise his composition. He found the Divisionist technique hard, and wrote that he needed models so that he could complete its detail, which he did later the following year.

British painter Adrian Stokes travelled to Romania in eastern Europe for this golden view of Harvest Time in Transylvania (c 1909), one of many paintings he and his wife Marianne made of their protracted visits.

Grant Wood’s Fall Plowing from 1931 is set in the prairie of Iowa, where it shows ripe and harvested cereals, and a recently developed walking plough with a steel ploughshare, an important advance in cultivating the prairie.

Henry Herbert La Thangue painted In the Orchard in 1893, presumably in Sussex, England, using a profusion of fine marks more typical of Impressionism. Although the figures and baskets of fruit are quite tightly detailed, much of the rest of his canvas is more painterly and atmospheric.

Yellow has also been used in combination with blues and greens to create colours closer to those in nature. In some cases, even into the twentieth century, the yellow used hasn’t proved lightfast, and has faded to leave foliage appearing blue.

This is all too sadly evident in Adriaen van de Velde’s otherwise superb Vertumnus and Pomona from 1670.

Carl Blechen used lightfast chrome yellow extensively in his imposing View of Assisi, painted in 1832-35. By this time, the mixture of chrome yellow with Prussian blue had become known as green cinnabar or chrome green, although the chromium salt used was yellow in colour, not green.

Chrome yellow was widely used by the Impressionists and shown at the Salon, and is demonstrated well in Paul Cézanne’s famous painting of The Railway Cutting (c 1870). Most if not all of the greens seen here most probably rely on chrome yellow mixed with blue.

When landscape artists take to the hills, they often head for rocky peaks and miss the undulating uplands of the foothills. So u in this alphabet of landscapes stands for those undulating uplands that roll rather than precipitate. In English they’re often referred to as downs, which might appear contradictory, although the word has common origins with dunes, which makes more sense, perhaps.

Samuel Palmer’s view of The Weald of Kent from about 1833-34 is typical of what you see looking down from a ridge at the valley below. This is an area of low hills between the main South and North Downs in the south-east of England.

Although a bit more rugged than the Downs of England, Arnold Böcklin’s view In the Alban Hills from 1851 shows these hills about 20 km (12 miles) south-east of the city of Rome. These have long been a popular escape from the city during the hot months of summer.

Jean-François Millet returned to the rolling Normandy countryside of his birth in The Hamlet of Cousin near Gréville (1855). This shows the rough lane leading to another nearby hamlet, Cousin, amid rolling countryside with hedgerows enclosing tiny fields.

Benjamin Williams Leader found A Welsh Cornfield in 1862 with its cereal crop cut by hand into stooks ready for threshing. One of the women is using a ladder stile to traverse the field’s dry stone wall. There’s fine attention to detail, including appropriate native plants, in accordance with the principles of Pre-Raphaelite landscape painting.

Camille Pissarro’s Côte de Jalais, Pontoise (1867) shows the hill of Les Jalais at l’Hermitage, where Pissarro lived, viewed from the Chemin des Mathurins in Pontoise, north of Paris.

When Ivan Pokhitonov was living in Belgium in 1912, he painted this view of The Walloon Village of Jupille, catching its fruit trees in blossom.

In 1915 Eugène Burnand painted his last major work, Ploughing in the Jorat, but his first version was destroyed by fire. He completed this second version the following year. This wide-screen pastoral landscape contains a patchwork of villages and farmland between forested hills, near where the artist lived, to the north of Lausanne in Switzerland.

Paul Nash’s view of the Cotswold Hills, from about 1920, shows the rolling countryside near his family home in Buckinghamshire, England. These hills sprawl across a large tract of central western England, to the west of Oxford.

Grant Wood’s Spring Turning from 1936 is a high aerial view of rolling countryside in the American rural Midwest, being ploughed using a pair of horses, during the Spring. Its bright green fields seem almost endless.

Around 1939, shortly before the start of the Second World War, Eric Ravilious visited the famous White Horse cut in the chalk downs at Uffington in Berkshire, England. The Vale of the White Horse (c 1939) shows the view from an unconventionally low angle, in pouring rain. This hill figure is thought to date from the late Bronze or early Iron Age, around three millennia ago.

Percy Shakespeare’s painting of December on the Downs, Wartime, made during the Second World War, shows one of the rolling chalk downs in the south of England, with both tractors and teams of horses working the land.