Environment

The World of Isles

Gehennum is on a world slightly larger than Earth, and yet less dense, so that gravity is no higher. It is a planet of low relief: the broad shallow ocean is dotted here and there with islands never larger than Ireland, and rarely as mountainous as Java. Its inhabitants distinguish it from other worlds of their acquaintance as 'the World of Isles'.

The low-density material of the World of Isles includes little of the heavier elements, so ores of iron, copper, tin, and other metals are less common than on Earth.

The circumference of the World of Isles is fifty thousand kilometres. A nautical mile is therefore 2.3 kilometres, and the distance to the horizon from a height of h metres is approximately (4 times the square root of h) kilometres.

Although there are arid islands at unfavourable latitudes, and 'rain shadow' sides to some larger islands, there are no extensive grasslands anywhere on the World of Isles. Therefore there are no large grasslands fauna. For example, there are no horses, lions, cheetahs, or gazelles. Elephants are of the smaller, 'Indian', forest type. The few patches of grassland support only such small animals as gophers, hares, and foxes.

As if to make up for the want of plains fauna, the World of Isles has lavish aquatic fauna, including an amphibious human species and a giant semi-intelligent predatory aquatic lizard, the sea-dragon.

Sky of the World of Isles

On the World of Isles the day is lit by a bright yellow-white sun, much like ours. Its apparent motions define a day of twenty-four hours and a year of 361 days, during which it wanders 18 degrees either side of the celestial equator.

A pale blotched moon, about the same apparent size as the Sun, goes through phases of the usual sort in a month of thirty-two days. A horde of stars decorate the night sky, and coagulate into a milky band that spans the heavens. There is a bright white planet which never strays far from the Sun, and one each of red, blue, and green which range the ecliptic, progressively dimmer and more sluggish.

A strange star or tiny moon called 'Indarian' hangs fixed in the sky, as though it were in geostationary orbit. It has about the same brightness as Venus at its brightest: Indarian can be seen by day if one knows where to look. On one half of the World of Isles it is an indispensable aid to navigation and a byword of constancy. On the other it is never seen.

Indarian seems to shine by its own light: it is never dimmed by eclipse.

The Gehennum archipelago

Gehennum is an extensive archipelago in the tropical zone, stretching 150 kilometres either side of the equator. It is about 1,500 kilometres from east to west, and includes about 6,000 islands and atolls, 880 of them inhabited.

Gehennum lies over an active subduction zone: there are many volcanoes, but much of the islands' material consists of upthrust, folded, and metamorphosed sedimentary rocks. These are now heavily eroded, and present a spectacular, but inconveniently rugged, landscape. The tallest mountain is Mount Parnas, on the large island of Bethany. Parnas is a volcanic cone 4,500 metres high (about half the height of Mount Everest), and is the tallest mountain on the World of Isles.

Basalt, limestone, marble, shale, and sandstone are common. Granite and other plutonic rocks are very rare. Minerals include flint, jade, volcanic glass, and some gemstones. Iron and copper ores are rare, other metal ores very much so. But as metals are rare all over the World of Isles, Gehennum is relatively well-endowed with metal ores.

All the islands are surrounded by coral reefs. This makes the few harbours at which it is possible to get a ship to the shore very valuable. In many places coral lagoons have been raised above sea level following earthquakes, producing stretches of level, swampy ground behind sea-cliffs of porous limestone. On some coasts repetitions of this process have produced a terraced terrain, now extensively cultivated.

Click here for a map.

Climate of Gehennum

Gehennum lies on the equator, and because of its warm shallow seas and the small inclination of the ecliptic, the seasonal trade winds never invade it. As there are no large plateaus on the World of Isles to induce monsoons, Gehennum is plunged into permanent doldrums. At sea, only fitful winds blow, and if the occasional storms swell into hurricanes, their paths take them well out of the archipelago before they develop their full fury. There are no discernable seasons in Gehennum, and only those who watch the stars are aware of the length of the year.

Near the coast sea breezes blow from mid-morning until sunset, and land breezes from mid-evening until dawn. These allow sailing vessels to operate along the coasts, but for trips between any but the closest islands, power is necessary, and this requires magic, miracles, or oars.

The climate is hot and wet. At sea level the temperature ranges from an overnight minimum of about 25 celsius (77 Farenheit) to a daily maximum or 32 to 33 celsius (89 to 92 Farenheit). Regular afternoon thunderstorms are the rule, and serein sometimes falls after dusk. These thunderstorms produce an average of about 3,500 millimetres of rain per year at sea level.

Catabatic (downslope) winds at night and anabatic (upslope) winds in the day extend the regime of the coastal winds inland, and thus keep the overall humidity high. Temperature drops by about 6.5 celsius per thousand metres of altitude, and the orographic effect increases rainfall to its maximum of 5,000 millimetres per year at about the altitude of 1000 metres. Above 1,500 metres conditions become gradually drier, and teak forests replace the coastal jungle.

On the large island of Bethany, one mountain reaches 4,500 metres, and is capped with ice and snow. This is Mount Parnas, tallest on the World of Isles. It is half the height of Everest.

One effect of this climatic regime is to keep Gehennum isolated from the rest of the world. Foreigners blow with the sea-wrack into equatorial waters, then drift on the currents to Gehennum, to wash up with the flotsam on the outer beaches. To get away is beyond the means of most- it takes a magician, a miracle, or many rowers to drag a sailing ship out of the intertropical convergence and into the trade winds.

The Gehennese learn much about other lands, and give very little away. In the legends of far countries Gehennum is a mythical land where lost things go, a land of no return.

Vegetation of Gehennum

The flora of Gehennum is by-and-large equivalent to those of Indochina and the East Indies. There is a diverse tropical rainforest in the coastal zone, with teak forests in the highlands. The peaks of the very tall volcanoes stick up above the usual cloud layer, and have an alpine meadow flora succeeded ultimately by ice and snow.

Rice is a major crop, and a multitude of fruits and spices, some of them doubtless introduced, are grown in plantations or gathered from the wild. Tea, coffee, opium poppies, coca leaf, and bhang (psychoactive hemp) are widely cultivated. The major fibre crop is hemp, though some flax is grown, and sericulture is practised in the cool of the greater altitudes.

Animals of Gehennum

The Gehennese forests abound with wild pigs, small deer, a type of goat, monkeys, gibbons, orang-utans, wild duck, bantams, parrots and other birds. Predators are less numerous, but include tigers, leopards, fishing cats, wildcats, wild dogs, serpents and pythons. The Gehennese forests are also the home of the elephant, found nowhere else.

The alpine regions are frequented by goats, hares, hyraxes, mountain lions, foxes, martens, lynxes, and eagles, among other species.

The domestic animals of Gehennum include the dog, pig, ox, cat, hen, duck, and elephant. Small pythons are domesticated to destroy mice and rats in grain stores.


Copyright © 1989—2004 Brett Evill. All rights reserved


Copyright © 1991 by Brett Evill. All rights reserved.