An Atmospheric Railway is a railway so called in consequence of the motive power being derived from the pressure of the atmosphere, or from compressed air. The idea of thus obtaining motion was first suggested by the French engineer Papin, about 1700. In 1810, and again in 1827, a Mr. Medhurst published a scheme for 'propelling carriages through a close-fitting air-tight tunnel by forcing in air behind them' and in 1825 a similar project was patented by a Mr. Yallance of Brighton. About 1835 a Mr. H. Pinkus, an American residing in England, patented a pneumatic railway. The carriages were to travel on an open line of rails, along which a cast-iron tube of between 3 and 4 feet diameter was to be laid, having a longitudinal slit from 1 to 2 inches wide and closed by a flexible valve along its upper side, through which a connection could be formed between the leading carriage and a piston working within the tube. This method was improved by Messrs. Clegg and Samuda, who in 1840 tried some experiments on a portion of the West London Railway with sufficient success to induce the government to advance a loan to the Dublin and KingstownRailway Company, for the construction of a pneumatic line from Kingstown to Dalkey. It was opened for passenger traffic at the end of 1843, and was worked for many months. The London and Croydon Company subsequently obtained powers for laying down an atmospheric railway by the side of their other line from London to Croydon, and in experimental trips in 1845 a speed of 30 miles an hour was obtained with sixteen carriages, and of 70 miles an hour with six carriages. But during the intense heat of the summer of 1846 the iron tube frequently became so hot as to melt the composition which sealed the valve, and the line had to be worked by locomotives. The mechanical difficulty of commanding a sufficient amount of rarefaction led to the abandonment of the system for railway purposes. It was revived, however, for the conveyance of letters and
arcels in towns by means of tubes of moderate diameter laid beneath the streets, but not proceeded with. Within offices, however, atmospheric railways or rather pneumatic despatch systems are used notably within the supermarket chain Sainsburys where cash from tills is put into a cylindrical container which is closed and inserted into a pressurised pipe system for conveyance to the cash office. Research Atmospheric Railway
A bicycle is a two wheeled vehicle driven by the riders feet pushing on cranks or pedals. A common misconception is that the earliest form of bicycle was the dandy-horse, which was pushed along by the rider's feet. However, while both the dandy-horse and the later bicycle are both velocipedes, the dandy-horse is not propelled by cranks.
The first bicycle was introduced to England from France in 1868, and comprised two solid wheels of equal size fitted to a frame, much like a modern bicycle in appearance, with a saddle fitted in the centre and propelled by cranks attached to the front wheel. This vehicle provided such a bumpy ride to the rider that it became popularly known as 'the bone-shaker'. Later came the Penny-Farthing with pedals fixed to the large front wheel which was made large to achieve high speeds. Later still, around 1895, came the safety bicycle with pedals driving the rear wheel by way of a chain, and the rider sitting upon a saddle set back from the front wheel so as to reduce the chances of falling forwards over the handlebars, from this developed the Raleigh bicycle design of 1900 which forms the basis of the modern bicycle. In 1888 the two-person tandem bicycle was invented.
In 1906 it was reported that speeds of 50 mph were attained on a bicycle. Around the same time, slightly earlier, the motorised bicycle (motorcycle or motorbike) was invented.
A typical bicycle is comprised of several parts. The principal and essential being: the frame, front forks, wheels, pedals, saddle, handlebars, chain and brakes. The largest part of the bicycle is the frame, and these vary in design depending upon the specialised intention of the bicycle.
A frame for a BMX bicycle being small, heavily braced and made of aluminium. The frame for BMX xyxling needs to be strong so as to endure the stresses of the bumpy ride, and the saddle low as competitors never sit down during a competition and as such they need space to sprint and jump with ease.
Cross-Country cycle frames are generally made of aluminium and carbon-fibre so as to be light weight. They are relatively small frames to allow quick and easy mounting and dismounting off road, and strong to endure off-road bumpy conditions. The smaller frames are often compensated for by having a longer seat post to allow a normal height saddle position.
The cycle speedway bicycle frame is designed primarily for strength, and as such is typically made from steel or aluminium.
Road racing bicycle frames are designed to be light and stiff. Traditionally they ewre made of steel, but by the start of the 21st century carbon fibre was being used for the more expensive models as this offered the same stiffness at reduced weight. The design of the tubes also developed over time, tubes becoming of a larger diameter, but thinner walls, to allow the same stiffness with reduced weight.
Bicycles are fitted with various types of brake, the most popular being the calliper, cantilever, hydraulic or disc and the V brake. The most common form of brake found on leisure bicycles, is that form used also on road racing bicycles. The calliper brake. Calliper brakes are a very efficient means of rim braking and basically comprise two blocks of rubber or plastic which are squeezed onto the wheel rim when the brake lever is squeezed by the ride.
Cantilever brakes operate on the same principal as calliper brakes, but are of a slightly different design at the wheel end, offering increased clearance between the tyre and the brakepads and as such are frequently employed for cyclo-cross bicycles and mountain bikes.
The most efficient form of rim brake is the V brake. The V brake also offers the most clearance of any rim braking system, and is most often found on mountain bikes.
Hydraulic or disc brakes are the most efficient and powerful form of bicycle brake. They use the wheel hub to brake, rather than the rim. Disc brakes offer the most clearance, and as such are used on mountain bikes, but are also expensive to fit and maintain.
Bicycle wheels are generally of one of three types. The most common and traitional bicycle wheel is the spoked wheel, comprising a rim connected to the central bub by a series of thin metal rods known as spokes. Spoked wheels are light in weight. Less common than spoked wheels, but offering greater strength and durability at the expense of weight are mag wheels which comprise a rim attached to the hub by a few, thick solid plastic bars. Solid wheels, also known as disc wheels, are made from composite material or carbon fibre are very strong, stiff, aerodynamic and very expensive. They are rarely used except as rear wheels in time-trialing and track racing. Research Bicycle More pictures of Bicycle
The chain is a unit of the imperial scale of measurement of length equivalent to 22 yards or 20.168 metres. A chain is comprised of 100 links, each 7.92 inches long. 10 chains equal one furlong, and 10 square chains equal one acre. It is sometimes called Gunter's chain, from its inventor. Research Chain
In arithmetic, a chain rule is a theorem for solving numerical problems by the composition of ratios, or compound proportion, by which, when several ratios of equality are given, the consequent of each being the same as the antecedent of the next, the relation between the first antecedent and the last consequent is discovered. Research Chain Rule
In geography, a col is a narrow, high pass through a mountain chain formed by the meeting of river or glacier valleys from opposite sides of the range. Research Col
Dredging is a term applied to the operation of removing mud, silt, and other deposits from the bottom of harbours, canals, rivers, docks, etc. The most simple dredging apparatus is the spoon apparatus, which consists of a strong iron ring or hoop, properly formed for making an impression upon the soft matter at the bottom, so as to scoop it into a large bag attached to the ring and perforated with a number of small holes. The means for working it is a long handle, a suspending rope, and a crane or sweep-pole planted in a boat.
Much more effective was the steam dredging-machine that became common during the 19th century. It had a succession of strong iron buckets on an endless chain, which traversed on a frame whose lower end was vertically adjustable so as to regulate the depth at which it worked. It was worked by steam, and the buckets tore up the matter at the bottom, raised it, and discharge it into punts or hoppers close to the dredging vessel. Various forms of steam - pump dredgers, in which suction-pipes were the chief features, were also used.
The river Clyde, from being a shallow stream, was converted, mainly by dredging, into a waterway carrying large vessels up to Glasgow.
Dredging rivers for gold has been largely carried on since the 19th century; and the gold-dredge may even be floated in water artificially supplied.
Dredging is also the operation of dragging the bottom of the sea for molluscs, plants, and other objects, it may be for scientific observation. The oyster-dredge is a light iron frame with a scraper like a narrow hoe on one side, and a bag attached to receive the oysters. The dredges used by naturalists are mostly modifications of or somewhat similar to the oyster-dredge. Scientific dredging assumed a high importance at the end of the 19th century for research into the life of deep-sea areas, before the invention of deep-sea diving equipment and cameras. Research Dredging
The ducking stool was in which shrewish offenders were bound and plunged in water as a punishment and torture. They were of different forms, but that most commonly in use consisted of an upright post and a transverse movable beam on which the seat was fitted or from which it was suspended by a chain. The penalty was inflicted on scolds of both sexes, quarrelsome married couples being immersed tied back-to-back. Ducking stools were extensively used throughout Britain from the 15th until the beginning of the 18th century, the last recorded use of the ducking stool in England was in 1809 at Leominster. Research Ducking Stool
A flail is two pieces of wood joined by a leatherthong or short metal chain and used for threshing. One piece of wood is held and the other then swung. Research Flail
The term fur is sometimes distinctively applied to hairy animal skins when prepared for being made into articles of dress, etc, while the name of peltry is given to them in an unprepared state or when merely dried. The animals chiefly sought after for the sake of their furs were the beaver, raccoon, musk-rat, squirrel, hare, rabbit, the chinchilla, bear (black, grey, and brown), otter, sea-otter, seal, wolf, wolverine or glutton, marten, ermine, lynx, coypou (nutria), polecat (fitch), opossum, fox, etc. All the preparation that skins require before being sent to the market is to make them perfectly dry, so as to prevent them from putrefying. This is done by exposing them to the heat of the sun or a fire. The small skins are sometimes previously steeped in a solution of alum. When stored in large quantities they must be carefully preserved from dampness, as well as from moths. The fur-dresser, on receiving the skins, first subjects them to a softening process. He next cleans them from loose pieces of the integument by scraping them with a metalblade. Finally, the fur is cleaned and combed, after which it is handed over to the cutter, who cuts the furs out into the various shapes required to make different articles.
In Europe the furtrade was fed chiefly by Russia, which yielded great quantities of furs, especially in the Asiatic portion of her dominions. Austria, Turkey, Scandinavia, etc, also yielded a certain quantity.
The furtrade of America has long been highly important, and several great trading companies were engaged in it, of which the Dutch East India Company was first. The French early took up the furtrade in Canada, and their chain of forts and trading posts at one time extended from Hudson's Bay to New Orleans. Quebec and Montreal were at first trading posts. In 1670 Charles II granted to Prince Rupert and others a charter empowering them to trade exclusively with the aborigines of the Hudson's Bay region. A company, then and after called the Hudson's Bay Company, was formed, which for a period of nearly two centuries possessed a monopoly of the furtrade in the vast tract of country known as the Hudson's Bay Territory. In the winter of 1783-1784 another company was formed at Montreal, called, the North-west fur Company, which disputed the right of the Hudson's Bay Company, and actively opposed it. After a long and bitter rivalry the two companies united in 1821, retaining the name of Hudson's Bay Company. The monopoly which had hitherto been enjoyed by the original company about Hudson's Bay was much extended; but in 1868 an act of parliament was passed to make provision for the surrender, upon certain terms, of all the territories belonging to the company, and for their incorporation with the Dominion of Canada. In 1869 the surrender was carried out, Canada paying 300,000 pounds to the company by way of compensation. The company still possessed large stretches of valuable land, and many houses, forts, and posts in the region formerly belonging to it. Its operations even extended beyond British America into the United States and to the Sandwich Islands and Alaska. It employed a large staff of agents, traders, Indian hunters, etc. Some of its posts were situated far north, almost approaching the Arctic Ocean.
In the United States, the fur-trade, especially that trade in beaverfur, was an important element in the economic life of all the colonies in the seventeenth century, and in the struggle between England and France for the possession of North America, also in all negotiations respecting the northwest boundary of the United States. In 1809 John Jacob Astor secured the incorporation of the American Fur Company. He founded Astoria in Oregon, and attempted to connect it with Mackinaw by a line of posts and consolidate the whole north-western fur-trade. After the War of 1812 he renewed his attempt. In 1816 the American Congress passed an act excluding foreign fur-traders. Research Fur-Trade
Glaciers are icy masses of great bulk, harder than snow, yet not exactly like common ice, which cover the summits and sides of mountains above the snow-line. They are found in Switzerland, Scandinavia, the Andes, etc.
They extend down into the valleys often far below the snow-line, and bear a considerable resemblance to a frozen torrent. They take their origin in the higher valleys, where they are formed by the congelation and compression of masses of snow in that condition called by French writers neve, by German authors, firn.
The ice of glaciers differs from that produced by the freezing of still water, and is composed of thin layers filled with air-bubbles. It is likewise more brittle and less transparent. The glaciers are continually moving downwards, and not unfrequently reach the borders of cultivation. The rate at which a glacier moves generally varies from 45 to 60 cm in twenty-four hours.
At its lower end it is generally very steep and inaccessible. In its middle course it resembles a frozen stream
with an undulating surface, broken up by fissures or crevasses. As it descends it experiences a gradualdiminution from the action of the sun and rain, and from the heat of the earth. Hence a phenomenon universally attendant on glaciers - the issue of a stream of ice-cold turbid water from their lower extremity. The descent of glaciers is shown by changes in the position of masses of rock at their sides and on their surface. A remarkable glacier phenomenon is that of moraines, as they are called, consisting of accumulations of stones and detritus piled up on the sides of the glacier, or scattered along the surface. They are composed of fragments of rock detached by the action of frost and other causes.
The fissures or crevasses by which glaciers are traversed are sometimes more than 30 meters in depth, and from being often covered with snow are exceedingly dangerous to travellers. One of the most famous glaciers of the Alps is the Mer de Glace, belonging to Mont Blanc, in the valley of Chamouni, about 1740 meters above sea level. It is more especially, however, in the chain of Monte Rosa that the phenomena of glaciers are exhibited in their greatest sublimity, as also in their most interesting phases from a scientific point of view.
Glaciers exist in all zones in which mountains rise above the snow-line. Those of Norway are well known, and they abound in Iceland and Spitzbergen. Hooker and other travellers gave accounts of those of the Himalaya. They are conspicuous on the Andes, while the Southern Alps of New Zealandrival in this respect the Alpine regions of Switzerland.
The problem of the descent of the glaciers is of extraordinary interest, and various theories have been put forward to account for it. It was shown by Professor Forbes, of Edinburgh, that a glacier moves very much like a river; the middle and upper parts faster than the sides and the bottom; and he showed that glacier motion was analogous to the way in which a mass of thick mortar or a quantity of pitch flows down in an inclined trough. His theory is known as the viscous theory of glaciers, which presupposes that ice is a plastic body, and this plasticity has been satisfactorily explained by Professor James Thomson of Glasgow by the phenomenon of the melting and refreezing of ice.
Water, he discovered, when subjected to pressure, freezes at a lower temperature than when the pressure is removed. Consequently when ice is subjected to pressure it melts; if it is relieved of pressure the water again solidifies. Therefore if two pieces of ice are pressed together, they tend to relieve themselves by melting at their points of contact, and the water thus produced immediately solidifies on its escape. If ice is strained in any way it similarly relieves itself at the strained parts, and a similar regelation follows. This, when applied to the glaciers, gives a complete explanation of their plasticity. Pressed downwards by the vast superincumbent mass, the ice gradually yields. Melting and re-freezing takes place at some parts, at others the gradual yielding at strained points goes on. In the latter process there is no visible melting, but there is the gradual yielding from point to point to the pressure above, and there is the transference relatively to each other of the molecules that constitute the, at first sight, solid mass. If, however, at certain points the strain is intense, the ice becomes extremely brittle. The latter fact disposes of Tyndall's objection to Forbes' theory, which was based on the fact that crevasses proved the brittleness, and not the viscosity of ice. Research Glacier
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Abbreviations
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