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7月26日
The Rotary Dial
In Strowger's system, selecting digits to dial was done by a complicated system involving five separate wires. Later, the system of Timed Pulse (TP) dialling was inventned using a rotary dial. With TP dialling, only one pair of wires is required for a telephone, the speech pair. To dial a digit, the circuit is interrupted according to the number dialled so, for example, if you dialled a '4' then the line would be pulsed four times, quickly in succession. After a moment, it was assumed that the digit was complete and that any further pulses belonged to the next digit. In order to ensure that successive digits didn't come too soon and thus be mistaken for pulses belonging to the previous digit, the finger stop on the dial was put some way round so that after removing your finger from the dial, there was a minimum time taken for the dial to return to the home position. It is important to note here that for the purposes of dialling, the digit '0' sends TEN pulses for dialling - i.e. the selector will step around to the 10th position.
Selector Theory
A selector starts in the 'home' position and with each 'impulse' the wiper contacts progress round the output bank to the next position. Each output would be connected to a different subscriber, thus the caller could connect to any other subscriber who was connected to that bank, without any manual assistance from an operator.
By mounting several arcs of outlets on top of each other, the number of outlets can be increased significantly but the wipers are then required to move both horizontally to select a bank and then vertically to move around that bank to the required outlet. Such a selector is known as a Two-Motion Selector. Two-motion selectors typically have 10 rows of 10 outlets, thus 100 possible outlets altogether. A two-motion selector can therefore accept two dialled digits from a subscriber and route the call to any of 100 numbers. The selector 'wipers' always start in their resting 'home' position. The first digit moves the selector veritically up to the corresponding level and then the second digit moves the wipers around the contacts of that level.
The Final Selector takes the final two digits of the number dialled. Most numbers dialled are several digits longer, and therefore pass through a chain of selectors. Selectors previous to the Final Selectors are different; they are called Group Selectors. Group selectors take only ONE digit from the caller, and step up the number of levels according to the digit dialled. The rotary movement is then automatic; the wipers search around that level to find a free outlet - i.e. the next free selector in the chain.
7月21日 Almon Brown Strowger (1839 – May 26, 1902) gave his name to the electromechanical telephone exchange technology that was his invention and his patent.
Early years
He was born in Penfield, near Rochester, New York. Little information is available about his early life, but it is known that he was the grandson of the second settler and first miller in Penfield. In her history of the Town of Penfield, Katherine Thompson reports that if his mother gave her children a task, he and his brothers would spend most of their time figuring out a machine that would do the task for them. He taught school in Penfield for a time, and served in the 8th New York Volunteer Cavalry during the American Civil War. His grave is marked with the traditional white headstone with an inscription that reads:
- Lieut. A.B. Strowger, Co. A, 8 NY Cav.
It is believed that he fought in the Second Battle of Bull Run near Manassas, Virginia.
After the Civil War, it appears he first became a country school teacher before he became an undertaker. He is variously attributed as living in El Dorado, Kansas or Topeka, Kansas, and finally Kansas City, Missouri. It is not clear where his idea of an automatic telephone exchange was originally conceived, but his patent application identifies him as being a resident of Kansas City, Missouri on March 10, 1891.
The story has it that Strowger, who according to historians was described as "eccentric, irascible and even mad," was motivated to invent an automatic telephone exchange after having difficulties with the local telephone operators. He was said to be convinced that the local manual telephone exchange operators were sending calls to his competitor rather than his business. He also suspected that the telephone operators were influencing the choice of undertaker when his business was requested. The origin of this suspicion reportedly arose from an incident in Topeka when a friend died and the family contacted a rival undertaker. Other stories claim that the wife or, possibly, the cousin of a rival was a telephone operator and Strowger suspected that the operators were telling callers that his line was busy or connecting his callers to the competition. No reliable details survive to substantiate these claims. Hence on inventing his switch he said "No longer will my competitor steal all my business just because his wife is a BELL operator.
Later years
Convinced that subscribers should choose who was called, rather than the operator, he first conceived his invention in 1888, and patented the automatic telephone exchange in 1891. It is reported that he initially constructed a model of his invention from a round collar box and some straight pins.
So what was so revolutionary about his invention that so many others had failed to devise previously? The patent consists of:
- A device for use by customer - this creates trains of on-off current pulses corresponding to the digits 0-9 (this evolved into the rotary dial telephone)
- A 2 motion stepping switch at telephone exchange. Rotating arm steps over, in a semi-circular fashion, 10 possible contact points. The stepping motion was controlled by the current pulses coming from the originating customer's dialing device.
- Cascading enabled connection among more than 10 customers. Switching devices can also be positioned in the vertical direction as well as horizontal direction, also increasing the switching capacity.
The addition of a line finder selector to reduce the number of switches needed, and circuits to detect busy connections were made in later designs. But these were minor enhancements to the fundamental concept.
It is the fundamental modularity of the system combined with its step-by-step (hence the alternative name) selection process and an almost unlimited potential for expansion that gives the Strowger system its technical advantage: previous systems had all been designed for a fixed number of subscribers to be switched directly to each other in a mesh arrangement. This became orders of magnitude more complex as each new customer was added, as each new customer needed a switch to connect to every other customer. In modern terminology, the previous systems were simply not scalable.
While he may have come up with the idea, he was not alone in his endeavours and sought the assistance of his nephew William and others with a knowledge of electricity and money to realise his concepts. With this help the Strowger Automatic Telephone Exchange Company was formed and it installed and opened the first commercial exchange in (his then home town of) La Porte, Indiana on November 3, 1892, with about 75 subscribers and capacity for 99.
The company's engineers continued development of Strowger's designs and submitted several patents in the names of its employees. It also underwent several name changes. Strowger himself seems to have not taken part in this further development. He subsequently moved to St. Petersburg, Pinellas County, Florida and appears to have returned to being an undertaker, as H.P. Bussey Funeral Home records report an unidentified body being moved "for Mr. Strowger" in December 1899. The same funeral home subsequently buried Strowger himself. Strowger was a man of some wealth at his death and was reported as owning at least a city block of property.
Death and afterwards
He died, aged 62, of an aneurism after suffering from anemia, at St. Petersburg, Pinellas County, Florida and was buried in Greenwood Cemeterythe next day.
He was survived by his widow Susan A. Strowger (1846 - 1921). After her death in Tampa, Florida, on April 14, 1921, her obituary appeared in the St. Petersburg Times, claiming she had additional "revolutionary" Strowger designs, but she had refused to make them public while she was alive because only others would profit from her husband's designs. She had claimed that her husband had only received $10,000 for his invention, when he should have received a million.
Strowger sold his patents in 1896 for $1,800 and sold his share in the Automatic Electric Company for $10,000 in 1898. His patents subsequently sold for $2.5 Million in 1916.
A bronze plaque, to commemorate his invention, was placed on his grave in 1945 by telephone company officials. Strowger was admitted to the hall of fame of the U.S. Independent Telephone Association (now called the USTA) in 1965. Apart from his invention, his name has also been given to a locomotive and a company business award.
In 2003, the Verizon Foundation awarded $4500 to Pinellas Heritage, Inc. and the Pinellas Genealogy Society in Strowger's memory. The funds were used to develop a website to impart the history of the cemetery where Strowger is buried, and to restore two Civil War memorials. The Greenwood Cemetery project won an organization achievement award from the Florida Trust for Historic Preservation.
Patents
7月20日
The name Surrey derives from 'Sudergeona' or (southern region), a Saxon sub-kingdom of AD 67 that was part of a much larger kingdom including Middlesex to the North of the Thames.
During Roman Times Surrey held little importance and remained largely rural the only areas of importance being the Roman roads going from London to the south coast.
During Saxon times Surrey did play a more important role with at least seven Saxon Kings being crowned in the town of Kingston. Which is now a large town on the banks of the River Thames that has long been associated with royalty.
The following questions and answers were collected from GCSE exams, and are some of the answers given by British students writing their fifth form GCSE Exams. These are genuine responses!!
Geography
Q: Name the four seasons
A: Salt, pepper, mustard and vinegar
Q: Explain one of the processes by which water can be made safe to drink
A: Flirtation makes water safe to drink because it removes large pollutants like grit, sand, dead sheep and canoeists
Q: How is dew formed?
A: The sun shines down on the leaves and makes them perspire
Q: What is a planet?
A: A body of earth surrounded by sky
Q: What causes the tides in the oceans?
A: The tides are a fight between the Earth and the Moon. All water tends to flow towards the moon, because there is no water on the moon, and nature abhors a vacuum. I forget why the sun joins in this fight.
Sociology
Q: What guarantees may a mortgage company insist on?
A: If you are buying a house, they will insist you are well endowed.
Q: In a democratic society, how important are elections?
A: Very important. Sex can only happen when a male gets an election.
Q: What are steroids?
A: Things for keeping carpets still on the stairs
Biology
Q: What happens to your body as you age?
A: When you get old, so do your bowels and you get intercontinental.
Q: What happens to a boy when he reaches puberty?
A: He says goodbye to his boyhood and looks forward to his adultery
Q: Name a major disease associated with cigarettes
A: Premature death
Q: What is artificial insemination?
A: When the farmer does it to the bull instead of the cow
Q: How can you delay milk turning sour?
A: Keep it in the cow. [He got an A]
Q: How are the main parts of the body categorised? (e.g. abdomen.)
A: The body is consisted into three parts - the brainium, the borax, the abdominal cavity. The brainium contains the brain, the borax contains the heart and lungs, and the abdominal cavity contains the five bowels, A,E,I,O and U
Q: What is the Fibula?
A: A small lie
Q: What does "varicose" mean?
A: Nearby
Q: What is the most common form of birth control?
A: Most people prevent contraception by wearing a condominium
Q: Give the meaning of the term "Caesarean Section."
A: The caesarean section is a district in Rome
Q: What is a seizure?
A: A Roman emperor
Q: What is a terminal illness?
A: When you are sick at the airport
Q: Give an example of a fungus. What is a characteristic feature?
A: Mushrooms. They always grow in damp places and they look like umbrellas
English
Q: Use the word "judicious" in a sentence to show you understand its meaning
A: Hands that judicious can be soft as your face
Q: What does the word "benign" mean?
A: Benign is what you will be after you be eight
Technology
Q: What is a turbine?
A: Something an Arab or Sikh wears on his head
assband as in "Am assband", "I am confined to the
house".
Awss a four-legged animal on which money is won
or lost.
blinding excellent, as in "West Am/Tottenham/Arsenal
are blinding" (delete as appropriate).
bruvver male sibling (or Mitchell).
cort a panda quarter pound hamburger.
cach sofa, settee.
caf daytime eating house.
dan ill a) in the direction of the bottom of an incline,
b) decline, ie.
"Kat from EastEnders gone a bit dan ill lately."
donut idiot.
eassband as in "Eassband, mate" (instructions to cabbie
to take Essex man in an easterly direction).
effix moral principles.
Fanx an expression of gratitude.
Fink ponder.
Furrock where to find the Lakeside Shopping Centre.
gaff house or home.
garrij the motah's gaff.
haitch letter between G and I (usually dropped).
Ibeefa Balearic holiday island.
innit a) is it not? A superfluous suffix, as in: "I'm
goana Saffend, innit."
jacks £5 note.
janartamean do you understand me?
kebab meat meal (for when you have the munchies).
lame of poor quality or taste. For emphasis use "well
lame".
Larf laugh, as in: "You're avin a larf" - you cannot
be serious.
minger an unattractive person, usually female.
motah car (generic); usually Ford Fiesta.
mullered (also trolleyed, bladdered) very, very drunk.
muppet idiot.
nice wun Congratulations!
no wurriz a) never mind, b) you're welcome.
oi oi! traditional greeting.
oppit go away.
padda puff soft, lacking aggression.
paipa The Sun.
quality good, great. As in: "Paulo di Canio is quality."
rear of the year idiot. Literally "prize a**e".
space cadet a person with plenty of space where their brain
should be.
spoze to be inclined to think.
tan London, as in "I'm goan up tan".
ug an unattractive person, male or female.
vacher a document that can be exchanged for goods
or services.
webbats where, in which place, specifically; as in:
"Webbats you goin, squire?"
wonnid a) desired or needed, b) sought by the police,
as in: "Ees wonnid by the awforties."
yafta you must; you are obliged.
yooz lot the assembled company.
zaggerate to suggest something is better than it is. Like
West Am's chances of avoiding relegation. Living in Surrey for most of my life I have long been fascinated by Coal Posts. You must have seen them white posts bearing the arms of the City of London in red.
From mediaeval times the City of London Corporation collected taxes on coal and wood being brought into the city.
In 1861 the London Coal and Wine Duties Continuance Act led to the setting up of the coal and wine tax posts. The funds collected were used to pay Londons debts, as well as for building bridges over the Thames, pavements, roads, Thames embankment etc. The growth of canal and railway traffic meant extra collecting points for taxes had to be set up outside the City boundaries. These points were by canals, railways, tracks and roads into London.
The tax was finally officially ended in 1889, but many posts remain. Of the original 260 posts more than 200 still remain in a ring around London.
Clearly a lot of money was collected over a great many years. So who did the collecting? Was a tax collector standing by each of the 260 Coal Posts each day to collect the money, or was a nearby resident responsible? What was the fee for a wagon load of coal?
Does anyone know?
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