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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 brake pads 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.
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Agabus is a genus of predacious diving beetles of the family Dytiscidae, with twenty species occurring in Britain ranging from eight to eleven millimetres in length. They are mostly dark brown and the males have tiny suction pads or patches of adhesive hairs on the under side of the widened first segments of the fore and middle tarsi. They live chiefly in cold, clear water.
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The Gecko are a family of nocturnal lizards (Gekotidae) characterized by the general flatness of their form, especially of the head, which is rather triangular. The body is covered on the upper part with numerous round prominences or warts and the feet are rather short with toes nearly equal in length and furnished with flattened suction pads which enable the gecko to run up perpendicular walls. The greatest number feed on insects and their larvae and pupae. Several of the species infest houses, where, although they are perfectly innocuous, their appearance makes them unwelcome tenants. One species is common in North Africa and Southern Europe.
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The Hyracoidea or Hyrax as they are commonly known, are an order of Eutheria. They are small rabbit-like creatures. Also called rock hyrax or cony, they are found in Africa and parts of the Middle East. Some species are tree dwellers, while others live on the ground; they feed on vegetation. They are about 50 centimetres in length. The head is thick and pointed, with short, rounded ears and a short neck. The body is squat, with short thin legs and a rudimentary tail. The feet, which are equipped with soft, elastic pads for climbing, have hoof like claws; each forefoot has four toes, and each hind foot has three. The inner toe on each foot is much reduced in size.
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The rabbit is a long eared burrowing mammal of the family Leporidae. The rabbit was introduced to England by the Normans, the term rabbit being originally applied to the suckling young, the adults being called conies. The hindlegs are longer than the forelegs, and instead of pads on the soles protecting the feet, all Leporidae have a thick coating of hair which gives a firm grip either on hard rock or slippery snow. The tail is very short and turned up. The fur is of a triple formation; there is a dense, soft, woolly under fur, through which project the longer and stronger hairs which give the coat its colour, and a still longer but much less numerous set, scattered among the others.
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The Addressograph was an early 20th century addressing machine by which printed matter, not necessarily limited to addresses, could be put on paper by the use of embossed metal printing plates. Different matter was printed at each stroke of the machine at speeds varying from 500 to 7,000 items each hour, according to the particular type of machine used.
The printing plates were in one piece on which the type was embossed, or were made up of three parts, consisting of the embossed metal plate, a card printed from the plate, and a metal frame into which both the plate and card were inserted, the card being in the upper portion. The printing plates were filed into steel filing drawers and formed a complete card index.
The addressograph was provided with a magazine which was loaded directly from a drawer, which was then placed in position under the machine. At each stroke of the machine a plate was fed from the magazine, inked by means of pads, and then advanced into the printing position. After printing, the plate was returned automatically to the drawer in its original order. Means were provided for taking two or more impressions from the plate before allowing it to leave the printing point, and of skipping those plates not required. Also, if required a portion of a plate only could be printed. Automatic selecting means were provided which enabled which enabled the machine to print only those plates required, omitting all the others. The impression could be obtained through a typewriter ribbon when it was required to match a typewritten letter for example.
The material to be printed on was usually fed into the addressograph by hand, but some types of addressograph machines were provided with the means for automatically feeding the material to the printing position and stacking it after printing. The magazines of these machines could be loaded and the plates that had been printed removed without stopping the machine. Machines were also arranged to print onto paper from a roll which was then automatically cut to the required size. Means were also provided for printing matter such as the title of a newspaper or magazine in addition to the address on newspaper wrappers.
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The Mil Mi-28 (Havoc) is a Soviet combat helicopter. The Mi-28 can fly at a maximum speed of 300 kmh, can fly rearwards and sideways at speeds up to 100 kmh and is able to hover turn at 45 degrees per second. The Mi-28A combat helicopter is designed to destroy armoured and un-armoured combat material, low and slow flying airborne vehicles and other battlefield targets. The helicopter can be operated autonomously for long periods from poorly prepared pads in the forward area of operations. The Mi-28A has small sweptback mid-mounted stub wings with four suspension units. Countermeasures pods are mounted on the wingtips. The helicopter can be armed with a mixture of air-to-air and air-to-ground missiles, unguided rockets and podded guns. When a high priority target is detected, the pilot uses a helmet mounted target designator which allocates the target to the navigator's surveillance and fire control system. The navigator/weapons officer is then able to deploy guided weapons or gun against the target. The targeting system
follows the direction of the pilot's eyes. The Mi-28N Night Havoc is armed with up to 16 Shturm and Ataka anti-tank missiles. The Mi-28 is equipped with a turreted 2A42 30 mm cannon and can also carry four containers each with twenty 80 mm unguided rockets or with five 122 mm rockets. The helicopter can alternatively carry containers with grenade launchers, 23 mm guns, 12.7 mm and 7.62 mm machine-guns, aerial bombs and incendiary tanks.
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PADS is an abbreviation for Passive Advanced Sonobuoy
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SHIN PADS is an abbreviation for Shipboard Integrated Processing And Display System
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Fox-hunting is a barbaric blood sport, once a favourite English sport much practised during the autumnal and winter months by the British idle-rich. A traditional pack of foxhounds consisted of from 20 to 60 couples of hounds according to the frequency of the hunting days. These dogs were carefully bred and trained and were under the superintendence of one experienced man called the master, who had the general control of the whole 'field.' Under him were the huntsman, whose duty it was to look after the hounds in their kennels and direct them in the field. The huntsman was directly responsible for the hounds condition and training. Next to him were the whippers-in whose main duty was that of assisting generally the huntsman both in the kennels and in the field. A less important function of the whipper-in was that of urging on lagging hounds.
The night before the hunt, the gamekeeper, calculating on the habits of the fox to leave his burrow or 'earth' in search of food at night, blocked-up all the 'earths' after the foxes have left them. The confused and scared animals were thus forced to seek refuge in neighbouring thickets or other cover, generally near their 'earth', and this fact determined the arrangements of the day's hunting and slaughter.
The huntsmen assembled in the neighbourhood of the stopped 'earth' and drew the neighbouring coverts by throwing off the dogs to search for the fox. The presence of the fox was generally indicated by the whine of some old and experienced hound who had first scented a fox; but a fox may hang or keep within the covert for a long time. The person who first saw the fox leave the covert, break cover as it is called, gave the view-halloo after it had got some little distance, upon which the huntsman collected his hounds and set off in chase followed by the entire field on horse back.
The foxhounds followed almost entirely by scent, the fox being itself perhaps far ahead and out of sight. Wherever, therefore, the scent failed the hounds were said to be at fault, and there was a check until the scent was recovered. When the scent was good most of the hounds own it by giving tongue, and they are were then said to be in full cry.
The rider who was first in at the death (at which the exhausted and terrified fox was literally torn to pieces by the savage hounds) lashed the hounds off and secured the head, feet or pads, and tail or brush of the fox. The midland counties of England, Leicester, Warwick, Yorkshire, etc, were traditionally the most infamous for fox-hunting.
During the 20th century public opposition in Britain to fox-hunting and similarly barbaric pursuits increased, and nature-lovers formed organisations known as hunt-saboteurs to lead false scents and thus sabotage fox hunts, before eventually hunting with dogs was outlawed in the 1990's.
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The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
©1993 - 2009 The Probert Encyclopaedia
Southampton, United Kingdom
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