Silk-weaving was well-established around the Mediterranean by the beginning of the century, and figured silks, often silk velvets with silver-gilt wefts, are increasingly seen in Italian dress and in the dress of the rich throughout Europe. Stately floral designs featuring a pomegranate or artichoke motif had reached Europe from China in the previous century and became a dominant design in the Ottoman silk-producing cities of Istanbul and Bursa, and spread to silk weavers in Florence, Genoa, Venice, Valencia and Seville in this period.
Fur was worn, mostly as a lining layer, by those who could afford it. The grey and white squirrel furs of the Middle Ages, vair and miniver, went out of style except at court, first for men and then for women; the new fashionable furs were dark brown sable and marten. Toward the end of the century, wild animal furs such as lynx became popular. Ermine remained the prerogative and hallmark of royalty.
Markov chain
A Markov chain is a model of some random process that happens over time. Markov chains are called that because they follow a rule called the Markov property. The Markov property says that whatever happens next in a process only depends on how it is right now (the state). It doesn't have a "memory" of how it was before. It is helpful to think of a Markov chain as evolving through discrete steps in time, although the "step" doesn't need to have anything to do with time.
Markov chains can be discrete or continuous. Discrete Time Markov Chains are split up into discrete time steps, like t = 1, t = 2, t = 3, and so on. The probability that a chain will go from one state to another state depends only on the state that it's in right now. Continuous Time Markov Chains are chains where the time spent in each state is a real number. The amount of time the chain stays in a certain state is randomly picked from an exponential distribution, which basically means there's an average time a chain will stay in some state, plus or minus some random variation.
An example of a Markov chain are the dietary habits of a creature who only eats grapes, cheese or lettuce, and whose dietary habits conform to the following (artificial) rules:
This creature's eating habits can be modeled with a Markov chain since its choice depends on what it ate yesterday, not additionally on what it ate 2 or 3 (or 4, etc...) days ago. One statistical property one could calculate is the expected percentage of the time the creature will eat cheese over a long period.
Another classical example of a Markov chain is the 1995 model of cocaine use in Los Angeles designed by the . The model is governed by a series of equations, which describe the probability of a person being a non-user, light user (L) or heavy user (H) of cocaine at time "t"+1, given their prior probabilities at time "t":
"L(t+1)" = "I"("t")"-aL(t) +fH(t)-bL(t)"
"H(t+1)" = "bL(t)-fH(t)-gH(t)"
"I(t)"+"L(t)"+"H(t)"=1
Mary Anning
Mary Anning (21 May 1799 – 9 March 1847) was an early 19th-century British fossil collector, dealer and paleontologist. She earned her living finding and preparing fossils, in the rich Jurassic marine strata at Lyme Regis, Dorset where she lived. She made many important finds. These included the first ichthyosaur skeleton to be correctly identified ("Temnodontosaurus platyodon"); the first two plesiosaur skeletons ever found ("Plesiosaurus dolichodeirus"); the first pterosaur skeleton found outside Germany ("Dimorphodon macronyx"); and some important fish fossils.
Her observations played a key role in the discoveries that belemnite fossils contained fossilized ink sacs, and that coprolites, known as bezoar stones at the time, were fossilized faeces. When the geologist Henry De la Beche painted "Duria Antiquior", he based it largely on fossils Anning had found. He sold prints for her benefit. Her work played a key role in the growth of scientific biology in the early 19th century. It showed without question that previously unknown forms of life had existed in the Jurassic seas, all of which were long extinct.
Anning's sex and social class—her parents were poor religious dissenters (non-Anglican Protestants)—prevented her from fully participating in the scientific community of early 19th century England, dominated as it was by rich Anglican gentlemen. Some of the men she worked with and for did give her full credit for her contributions, but some did not.
Although she became well known in geological circles in Britain, Europe, and America, and she made a great deal of money from her best finds, she struggled financially for much of her life. In 1818 Anning came to the attention of Thomas Birch, a rich fossil collector, when she sold him an ichthyosaur skeleton. A year later, he was disturbed by the poverty of the Anning family, which was at the point of having to sell their furniture to make ends meet. Birch arranged for the sale by auction of his own fossil collection, and the proceeds (some £400) were given to the Annings. Besides providing much needed funds, the public auction raised the profile of the Anning family in the geologic community. Later, she lost £300 (a huge sum) in 1835 on unwise investments, but was saved by a government pension of £25 per year. This was organised by another of her friends, William Buckland. Her early death was caused by breast cancer.
Tourists used to visit Lyme Regis, which had become a popular seaside resort. As their father had before them, Mary and her brother Joseph Anning set up a table of 'curiosities' near the coach stop at a local inn to sell their wares to tourists. After Joseph made an important find of an ichthyosaur skull in 1810 and Mary found the associated skeleton a year later, they became known to the geologists and amateurs interested in fossils. Their passion for fossils grew to be the main source of income for their family.
Her stock in trade were invertebrate fossils such as ammonite and belemnite shells, which were common in the area and sold for a few shillings. Vertebrate fossils were much rarer, and exceptional specimens like an almost complete ichthyosaur skeleton could sell for much more.
The source of these fossils were the coastal cliffs that surround Lyme which are part of a geological formation known as the Blue Lias. This formation consists of alternating layers of limestone and shale, laid down as sediment on a shallow seabed early in the Jurassic period (about 210-195 million years ago). The cliffs are one of the richest fossil locations in Britain.
As Mary Anning continued to make important finds her reputation grew. In 1826, at the age of 27, she managed to save enough money to buy a home with a glass store front window for her shop, called "Anning's Fossil Depot". The move was covered in the local paper, which noted that the shop currently had a fine ichthyosaur skeleton on display. Many geologists and fossil collectors from Europe and America visited Anning at Lyme to purchase specimens. These included the geologist George William Featherstonhaugh who purchased fossils for the newly opened New York Lyceum of Natural History in 1827. King Frederick Augustus II of Saxony visited her shop in 1844 and purchased an ichthyosaur skeleton for his extensive natural history collection.
Lady Harriet Silvester visited Lyme in 1824. She remarked in her diary: