Archive for November, 2011

Slow Newsreel Sunday

Sunday, November 20th, 2011

You know those Sundays when you wind up, without even realizing it, spending half the day watching a bunch of vintage newsreels and school guidance films? Or is that just me? Beware, for I shall drag down you down into my nerdly depths.

Reminiscent of the rise of Charles Foster Kane, this short from 1940 explains to the youth of America how “Journalism” works. The hats, the coats, the cars, the notebooks, mimeograph machines, copy editors wearing visors!, it’s all gold, Jerry. The best part, though, is the explanation of the important role of newswomen. It starts at 5:06 and is not to be missed.

[youtube=http://www.youtube.com/watch?v=dHgwFYbSF6E&w=430]

Here’s something from a bygone era: a 1937 film by the Works Progress Administration proving its benefit to the nation through construction of infrastructure — new secondary roads, reservoirs, sewage systems, community buildings, etc.

Here’s the WPA again, this time coming to the aid of the victims of a horrible Ohio River flood in 1937:

They mobilized 18,000 WPA workers in just the first two days, established long supply lines ensuring that food and water never ran out and prevented typhus with a campaign of innoculation right in the middle of the water. That’s pretty damn impressive.

Fast forward to 1959 and the celebrations attending Hawaiian statehood, complete with a burn on them lying Communists, of course:

There are millions more to suck away your next weekend at the Internet Moving Image Archive. I usually type in a random word (I started with “dancing” this time) and see what comes up, then I just link hop through the collections and subject tags.

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SciAm’s early archives free and patent models galore

Saturday, November 19th, 2011

Scientific American has recently digitized its archives, every issue of the magazine from the first one in August 28, 1845 to the most recent. Most of them can only be accessed by subscribers to the print edition, educational institutions with a site license or on a pay-per-view basis. There’s brief window during which those of us of a historico-nerdly bent can wallow as deeply as we please in all of the oldest issues free of charge. Until November 30, all of the Scientific American issues published between 1845 and 1909 will be available for free.

Each issue has a table of contents of individual articles that you can read or you can download the entire issue in a single pdf, which is what I’ve been doing because the cover and the advertisements are just as cool as the articles. SciAm’s Anecdotes from the Archives blog has an interesting entry on the first issue, which was tailored to appeal to people from many walks of life, not just scientists and inventors. There were book reviews, poems, even what appear to be News of the World-style tall tales categorized as “interesting news of passing events.”

In the three 1845 issues I’ve read thus far, new patents take a prominent position both in column-inches and in advertising. Little wonder, because the mid-19th century was a boom time for patents and new inventions. Patent models were exhibited in galleries and gazed upon like Old Master art.

Those days are upon us again, albeit in far reduced form, thanks to an exhibit of patent models at the Smithsonian that just opened on November 11. Inventing a Better Mousetrap: Patent Models from the Rothschild Collection will be at the Smithsonian American Art Museum until November 3, 2013. That’s the perfect location seeing as the building that now houses the American Art Museum (and the National Portrait Gallery) was authorized by President Andrew Jackson in the Patent Act of 1836, to serve as a fireproof patent office.

Jackson signed the bill on the Fourth of July. On December 15, 1836, while the new fireproof building was still in the early stages of construction, a fire broke out at Blodgett’s Hotel where the Patent Office shared space with the General Post Office and Washington City Post Office. Although there was a fire station right next door to guard against just such an eventuality, the engines had been equipped in 1820. The leather hose fell apart in the firefighters’ hands and the pump never even started. The Patent Office, the only building that the British left alone during the Burning of Washington in 1814 thanks solely to the intervention Dr. William Thornton, architect of the United States Capitol, inventor, physician and first Superintendent of the Patent Office, who convinced the British command to spare the Patent Office because of its importance to mankind, burned with all its contents.

All the patents and patent models kept since the creation of the office as per the U.S. Constitution (Article I, Section 8) and the Patent Act of 1790 were destroyed. The only patent records left were in a book that had been removed from the premises against Patent Office rules by a draftsman named William Steiger and whatever was in the memory of the sole patent examiner. That’s 10,000 patents, most of them lost irretrievably. There was an attempt to put the archive back together using private files and reproductions of the models. The Patent Office wrote to every inventor it could think of asking them to recreate models and paperwork. In the end, they were able to restore 2,845 of the 10,000 lost, all of them reissued with a patent number beginning with “X.” The patent numbers began again with “1” starting with ones issued in July because all of the most recent patents had been easily recovered from the inventors’ records.

Once safely ensconced in the new building, the patent models were put on public display. Admission was free and with the explosion of industrialization in the mid-19th century, inventions and mechanical models drew big crowds. Approximately 100,000 people a year visited the Patent Office in the 1850s to view the models held in three tiers of nine-foot-high display cases. In 1880, the Patent Office stopped requiring inventors to submit a model. It had accumulated 200,000 patent models by that date.

At the turn of the century, as the Department of the Interior grew and expanded into the Patent Office’s space, the models were removed from display and put in storage. Then, in 1924, Congress, which had once passed laws to help the Patent Office recover the records lost in the Great Fire, suddenly became concerned about the exorbitant cost of storing these “useless” models. It allocated $10,000 to get rid of that immense collection of the history of American ingenuity, mechanical science, industry, play, posthaste. The families of the inventors claimed some. Whatever museum asked for any got them (the Smithsonian claimed 2,500). The rest were all sold at auction in 1925.

Sir Henry Wellcome, founder of Wellcome Pharmaceutical Company (now Glaxo Smith Kline) and London’s splendid Wellcome Collection of medical artifacts and curiosities, purchased the entirety of the United States Patent Office’s models at the auction. He intended to build a museum of the patent model, but the Wall Street Crash of 1929 stopped him in his tracks. After his death in 1936, the trustees of Wellcome’s estate sold the patent models to a Broadway producer for $50,000. He sold it for $75,000 to a group of businessmen who also planned to build a museum, but they were forced to file for bankruptcy in 1941 and the models were sold to, of all people, an auctioneer named O. Rundle Gilbert for the measly sum of $5,000. Needless to say, after that, the models were sold to collectors far and wide.

It wasn’t until the 1970s that aerospace engineer Cliff Petersen bought all the crates Gilbert had left, 800 of them still in their 1926 packaging, and donated 30,000 of the models within to the United States Patent Model Foundation. He kept about 5,000 models for his personal collection.

Alan Rothschild, an inventor in his own right and model collector, bought the bulk of Petersen’s collection in the 1990s. He opened the Rothschild Petersen Patent Model Museum in 1998 to house the almost 4,000 patent models in his collection. Space at the museum is very limited, so the models are not on public display but only viewable upon appointment. They are regularly loaned to other institutions, however, and some are part of a travelling tour called The Curious World of Patent Models currently winding its way through the United States. You can find dates where the exhibit will be at a museum near you on this page.

Thirty-two of the models in the Rothschild Collection are part of the Smithsonian exhibit. Alan Rothschild himself will be at the American Art Museum for a lecture on December 1, 2011, 7–8 PM, along with curator Charles Robertson to discuss the patent models on display, their inventors and the period. Admission is free.

You can search the Rothschild Petersen Patent Model Museum’s collection online. They have an extensive database with featured items of interest as well as links to the original patent applications complete with explanations and drawings. The Smithsonian exhibit has a small but sweet picture slideshow here.

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Wreck of 17th c. “gaudy” ship found in Baltic

Friday, November 18th, 2011

Deep Sea Productions divers have discovered what they believe to be the wreck of the 17th century Swedish royal warship Svärdet, or “Sword” in English. The 82-foot ship was found on the seafloor between 160 and 320 feet deep off the coast of the island of Öland, not far from where the wreck of the 16th century Swedish warship Mars was discovered earlier this year.

Built in 1642, the Svärdet sank with near-legendary drama during the Battle of Öland on June 1, 1676, along with its sister-ship the Kronan, or “The Crown.” Built in the 1670s, the Kronan was the flagship of the Swedish fleet, one of the world’s largest seagoing vessels and one of its most heavily armed. Both it and Svärdet were richly decorated in a style known as a “gaudy” ship, designed to intimidate the enemy with size and fanciness. It didn’t work in this case.

When Admiral of the Realm Lorentz Creutz, the Kronan‘s commander, ordered the ship to turn hard south with open gunports and too much sail, the ship flooded and capsized. Then for a reason never fully explained the gunpowder magazine exploded, taking most of the bow with it and the ship sank taking over 800 men with her, including Creutz, other high-ranking naval officers and the navy’s chief doctor.

Taking advantage of the confusion caused by the Kronan‘s sudden implosion, the allied Dano-Norwegian-Dutch fleet surrounded the Svärdet, attacking it on all sides. Its commander, Admiral Claes Uggla, held off the four attacking vessels, including the flagships of the Danish and Dutch fleets, for two hours. Finally Svärdet lost its mainmast and was pierced below the waterline. Uggla refused to surrender, even after they were hit by a fireship which did its duty and infected the Svärdet with its flames. He and his entire company went down with the ship.

The Battle of Öland is the largest naval battle the Baltic has ever seen. The wreck of the Kronan was rediscovered in August of 1980 after decades of searching by a team headed by Anders Franzén, the marine engineer and amateur historian who had found the Vasa in 1956. Finally finding its sister is therefore enormously exciting.

Malcolm Dixelius, head of Deep Sea Productions, is cagey on its exact location. It was not discovered in Swedish waters, so Swedish conservation law does not apply.

“The Baltic Sea is very complicated… Different countries interpret the laws in different ways,” he said.

“What is important is that we know where it is and we will help scientists to investigate it. We are working with colleagues who found the Mars, since these two ships are fairly close to each other and have a common history,” he added.

The Mars sank in 1564 and was found last spring. Both the Mars and Svärdet “are untouched,” Dixelius said.

“No one has been on them. Both the Vasa and Kronan were stripped in the 1600s. Here all the cannons are still there. They probably knew in the 1600-1700s where these wrecks were, but couldn’t get at them, because they were so deep,” he said.

The Baltic is a shipwreck lover’s dream. Its low temperatures and low salt levels act as excellent preservatives and make the environment extremely inhospitable to critters who enjoy eating wood, like shipworm. You can see the remarkable condition the ship is in in this footage of the wreck:

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Significant Roman burials found in Cirencester

Thursday, November 17th, 2011

Archaeologists excavating the site of former automotive shop in Cirencester, in the Cotswolds, have discovered an extensive Roman burial ground with over 40 inhumations and four cremations.

Preliminary dating based on a pottery flagon found in a child’s grave suggests that the cemetery is from the early Roman period, between 70 A.D. and 120 A.D. If that date is confirmed by radiocarbon dating of the human remains themselves, that would make this one of the earliest burial grounds in Roman Britain and it would upend current historical thought about the overwhelming prevalence of cremation during this period.

Cotswold Archaeology project manager [Cliff] Bateman said the near perfect flagon was a significant find because it indicated the child could also have been buried in the early Roman period. It is thought inhumations were not common practice until after 200AD, so the team believe the find could re-write historians’ understanding of Roman Britain.

A large number of the inhumations were in shallow graves within a marked enclosure, which could have belonged to a family. And the flagon, which was likely to have been made in nearby Purton, was found in a young child’s grave within this enclosure.

Two bracelets made of green glass beads, jet beads, shale and copper alloy and a number of hobnails have also been found in the graves. One of the bracelets was discovered still encircling the skeletonized wrist of its owner.

This isn’t the first time burials have been found on this very location. When the Bridges Garage was built in the 1960s, archaeologist Richard Reece found 46 cremations, six inhumations and an engraved headstone dating between the first and third centuries A.D. Notice the opposite proportion of inhumations to cremations, which is what historians would have expected.

It’s remarkable that after the excavation and construction in the 60s that there was still a burial ground to be found today. The auto shop had two huge underground fuel tanks installed, so archaeologists really didn’t expect to find any material remains undamaged underneath the property. It took them three days of digging before they found the cremations. Then they found three inhumations and every day after that they found more.

The archaeological survey was done at the behest of St James’s Place Wealth Management who intended to build a parking deck on the spot. All construction has been put on hold and additional security hired to police the excavation site.

The artifacts discovered will be conserved and the human remains will be examined in detail at Cotswold Archaeology’s head office. They will be radiocarbon dated and osteological analysis will determine their age, sex, any injuries they might have incurred and whether they were fatal. After the research and conservation are done, the artifacts may go on display at Cirencester’s Corinium Museum.

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Bullets from English Civil War found in Newbury

Wednesday, November 16th, 2011

Archaeologists doing a survey of an English Civil War site in Newbury, Berkshire, have unearthed seven bullets from the First Battle of Newbury, a battle between the Royalist army led by King Charles and Parliamentarian force commanded by the Earl of Essex held on September 20, 1643. The team was doing exploratory work on Essex Street before sewer and water company Thames Water replaced a century-old cast iron water pipe in the area. They discovered the bullets in an adjacent field.

Mike Lang Hall, an archaeologist for Optimise, which is working on behalf of Thames Water, said: “This has been a very exciting find and it really is quite rare to find a collection of bullets like this dating back so many centuries in such an urbanised area.

Most of the bullets are consistent with use of a carbine rifle, a weapon that would have been a popular choice in the First Battle of Newbury, which we know took place on this street in September 1643.

The number of bullets in such a small area reflects the ferocity of the fighting – it is reported that sixty cartloads of dead were taken into Newbury for burial after the battle, in addition to those buried on the battlefield.”

The artifacts are now being studied at the Archaeological Surveys’ headquarters near Chippenham. So far they’ve confirmed that the bullets were probably shot from a carbine rifle and that all seven of them made contact with something solid at high speed. That something solid could have been topographical (ie, a tree) or anatomical (ie, a solider). Despite this and their advanced age, the bullets are in good condition, albeit misshapen from the impact.

The First Battle of Newbury was an important turning point in the First English Civil War. Up until then the Royalists had been winning, but even though King Charles had cavalry and got to the location first thus having his pick of the terrain, his soldiers were poorly trained and low on ammunition. Essex defeated all the King’s horses with mass infantry attacks and after a long, bloody day of fighting, the King beat a retreat under cover of night leaving Essex a clear path to take London.

The Royalists never recovered. Essex was welcomed by cheering crowds when he marched into London. They took the bull by the horns and parlayed that Parliamentarian fervor into prompt signature of the Solemn League and Covenant with Scotland on September 25, 1643. By January of 1644, Scotland would send an army to fight against King Charles.

With Scottish help, Parliamentary armies inflicted a string of defeats on the Royalists until King Charles surrendered to the Scottish army in May of 1646. They kept him for a year then handed him over to the Parliamentarians who expected him to accept the constitutional monarchy deal they offered. They did not expect him to cut a turncoat deal with the Scots himself so that in 1648 Scottish troops would yet again come south, only this time fighting for the King, and most importantly to them, to establish Presbyterianism in England. (Spoiler: the Scottish were as unsuccessful the second time as they had been successful the first. The King lost the Second Civil War too and his head with it.)

The bullets are still being examined, but will in due course go on display at West Berkshire Museum.

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A Map of a 19th c. Woman’s Heart

Tuesday, November 15th, 2011

I’m afraid it’s not terribly flattering. Coquetry, Selfishness, Love of Admiration, Love of Display and Love of Dress take up more than three quarters of the treacherous terrain that is a woman’s heart. Even in the Country of Solid Worth, encircled by the intimidating barrier of the Ego Mountains, the more serene territories of Hope, Enthusiasm and Platonic Affection are transected by the River of Lasciviousness.

It was published by D.W. Kellogg & Co. of Hartford, Connecticut, between 1833 and 1842. “The Open Country of Woman’s Heart” lithograph, subtitled “Exhibiting its internal communications, and the facilities and dangers to Travellers therein,” claims to have been created by “A Lady” but I don’t know if that’s true because I don’t see the Gigantic Sinkhole of Self-Loathing anywhere on the map. On the other hand, then as is now, there were plenty of women who held a low opinion of their gender’s innate failings so who knows?

The map is part of a fascinating online exhibit by the American Antiquarian Society in Worcester, Massachusetts, called “Beauty, Virtue and Vice: Images of Women in Nineteenth-Century American Prints.” Using their extensive collection of images from the colonial period through the Civil War and Reconstruction, the AAS give us a glimpse into the iconography of the 19th century and what it tells us about popular views of women in society, particularly the views of middle-to-upper class New England from whence many of the sources spring.

The exhibit connects this map to the Cult of True Womanhood, aka the Cult of Domesticity, as described in “The Cult of True Womanhood: 1820–1860,” (pdf) an influential 1966 paper by historian Barbara Welter. The “True Woman” of the 19th century was characterized by the four cardinal virtues of piety, purity, submissiveness, and domesticity. These were the divinely ordained provinces of the woman. Anything outside of that, from political activism to just having a job, could only lead women to a life of restlessness and unhappiness. Without her cardinal virtues to protect her, the woman is too easily debauched by the predations of ever-lustful men.

I’m not sure if the connection between map and True Womanhood is clear, however. The idea that women are inherently pure (albeit weak and temptation-prone, of course) and thus fulfilled only as mothers, wives, paragons of domesticity, doesn’t quite jibe with the vain, narcissistic, gold-digger depicted in the map. It reads more like the work of a penniless artist who got dumped for a rich dude to me.

Nonetheless, the exhibit is very much worth a read, as is the rest of the AAS website. I always appreciate when a museum or library makes an effort to give Internet viewers access to their collections, complete with nice big scans. That they’ve used their primary sources to create online exhibitions around a coherent theme makes it all the more readable and enjoyable. Next on my perusal list are Architectural Resources at the American Antiquarian Society and An Invitation to Dance: A History of Social Dance in America.

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William Hogarth’s house reopens after 3 years

Monday, November 14th, 2011

Eighteenth century painter, engraver and social satirist William Hogarth’s house in Chiswick, West London, has reopened after an extensive three-year restoration. It’s been a longer voyage than originally planned.

Hogarth, famous for his satirical prints condemning social ills of the era like the cheap gin that drove the poor to unemployment, dissolution, suicide, and the dangers of moral laxity among the moneyed classes, purchase the 1715 house as a country home in 1749. Chiswick was a small village surrounded by fields back then. Now it’s a suburb of London, dwarfed by sprawl and the A9 highway.

The house was closed to the public for renovation in September 2008. The construction work was finished by July of 2009 with only the museum’s new installations left to do before the scheduled reopening. Then a fire broke out in the electrical closet under the staircase. Firemen put out the blaze promptly but the damage was sufficient to require an additional two years of renovation. Thankfully the large collection of Hogarth’s prints owned by the museum trust was still in storage at the time of the fire.

The fire ended up being more blessing than curse in some ways. It revealed the original wood flooring of the house, and engendered major grants from the Heritage Lottery Fund, the John & Ruth Howard Charitable Trust, the Old Chiswick Protection Society and the William Hogarth Trust for a more complete renovation, the first full refurbishment of the house in 60 years. Along with the floors, the wall paneling was restored and fireplaces reopened. Also, experts in historical paint colors performed a detailed analysis of the original wall colors and recreated them exactly, so the current interior palette of grays and pinks is authentic to the house when Hogarth lived there.

The contents of the house are also true to the period, many of them artifacts original to the home that had long since been scattered. There are replicas of furniture depicted in Hogarth’s prints, his eye glasses, a Chinese porcelain punchbowl that the Hogarths must have loved because it was broken and mended several times, the stand for his pug’s food bowl, Hogarth’s painting chest, original engraved plates, even his palette — later used by J.M.W. Turner — which was loaned to the museum by the Royal Academy.

There are also portraits of Hogarth’s sisters (copies of originals now owned by Yale University) and his servants, a mourning ring for William’s wife Jane, and a number of other personal artifacts that belonged to his family members who remained in the house until 1808. The idea is to give a sense of how people lived in the house, not just to present a viewing gallery of Hogarth’s prints, which is why the curators have collected information about the various characters who lived there before and after the Hogarths as well.

The ground floor and first floor are open to the public. The ground floor includes a really smart feature that should be included in every museum of a historical house: computer displays that allow people who can’t climb the stairs to the second floor to take a virtual tour of the upstairs living quarters.

Another brilliant idea implemented by the museum is to offer replica 18th century suits for children to wear and compare themselves to the period portraits while they visit the house. I can’t even tell you how ecstatic I would have been to get to roam a museum in full costume.

The Hogarth’s House museum opened to the public on Tuesday, November 9th, the day before Hogarth’s 314th birthday. It’s open from noon to 5 PM, Tuesday through Sunday and admission is free. You can take a virtual tour of your own and learn more about Hogarth’s work with this audio slideshow from the BBC, narrated by Antiques Roadshow expert Lars Tharp.

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Hubble cleared of censoring rival Lemaître

Sunday, November 13th, 2011

American astronomer Edwin P. Hubble has traditionally been credited with the discovery that of the expanding universe. In 1929 he published a paper which described how the more distant a galaxy is from earth, the faster it appears to move away from us, a principle now known as Hubble’s Law. Using the speed of recession as deduced from redshift data (measured by astronomer Vesto Slipher) and the distance from earth to those galaxies (measured by Hubble himself), Hubble was able to calculate the cosmic expansion rate, a constant now known as the Hubble Constant. That discovery made him a luminary in the field and resulted in the coolest telescope ever being named after him in 1983.

The only problem is he wasn’t the first to discover it. Belgian priest and astronomer Georges Lemaître published his own findings about the velocity-distance relationship, including a nearly identical cosmic expansion constant deduced from recently published redshift data, in a French-language paper in the Annales de la Société Scientifique de Bruxelles in 1927. The journal was fairly obscure and the article only translated into English for publication in the Monthly Notices of the Royal Astronomical Society in 1931. The 1931 version, however, was missing key paragraphs about the expansion constant.

The spotty translation has long been known to historians and astronomers, but earlier this year controversy erupted over whether Hubble might have had something to do with muzzling his competition. Astronomer Sidney van den Bergh suggested (pdf) that the translator had intentionally dropped the cosmic expansion paragraphs, and mathematician David Block built on that (pdf), speculating that the “fiercely territorial” Hubble, concerned that he and the Mount Wilson Observatory in Pasadena, California, receive all the credit for the expanding universe, influenced the English publication to censor the paragraphs that showed that Lemaître had gotten there first.

There was no evidence of this but neither was their evidence exonerating Hubble from the charge, until now. Mario Livio, an astronomer at the Space Telescope Science Institute in Baltimore, Maryland, has found definitive proof that Hubble had nothing at all to do with the missing paragraphs. The culprit, as it happens, was none other than Georges Lemaître.

After going through hundreds of pieces of correspondence of the Royal Astronomical Society, as well as minutes of the RAS meetings, and material from the Lemaître Archive, Livio has discovered that Lemaître omitted the passages himself when he translated the paper into English!

In one of two “smoking-gun letters” uncovered by Livio, Lemaître wrote to the editors: “I did not find advisable to reprint the provisional discussion of radial velocities which is clearly of no actual interest, and also the geometrical note, which could be replaced by a small bibliography of ancient and new papers on the subject.”

As for why Lemaître chose to censor his earlier discovery of the expanding universe, the letters don’t provide his motivation. Livio thinks that Lemaître just didn’t particularly care to claim the find. The data he had used to calculate the expansion constant had been improved on since 1927, so his old work might have looked out of date. He also might not have thought there was much of a point to including his earlier but more tentative findings since Hubble’s had already been published two years before.

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Viking sailors found the sun using Iceland feldspar?

Saturday, November 12th, 2011

Vikings were known to have traveled extensively in the unfriendly waters of the North Atlantic, perhaps reaching as far as North America. How was it possible, in a time before the invention of the magnetic compass (in Europe, at any rate; they had magnetic compasses in Han Dynasty China (2nd c. B.C. – 1st c. A.D.), for sailors to navigate even under consistently overcast conditions when you can’t see the sun during the day nor the stars at night?

According to medieval Icelandic sagas, Vikings navigated using a sunstone, a mineral that polarizes light and thus allows the sun to be found even through heavy cloud cover. A passage in the 12th-13th century Rauðúlfs þáttr (pdf) saga describes its use:

The weather was overcast, and snow was falling, as Sigurður had predicted. The King then summoned Sigurður and Dagur into his presence. He sent a man out to observe the weather, and there was not a patch of clear sky to be seen. The King then asked Sigurður to determine how far the sun had travelled. He gave a precise answer. So the King had the sun-stone held aloft, and observed where it cast out a beam; the altitude it showed was exactly as Sigurður had said.

The sólarsteinn is mentioned in other sagas as well, described as a great treasure, and appears in several inventories of church property during the 14th and 15th centuries. None of the sources specify what mineral the sunstones were, however. There have been various likely candidates (cordierite, iolite, feldspar) since 1969 when Danish archaeologist Thorkild Ramskou first proposed that sunstones were real minerals with polarizing properties rather than legendary talismans with supernatural powers.

A new study led by University of Rennes physicist Guy Ropars found that a transparent calcite crystal known as Iceland feldspar, aka Iceland spar, can indeed find the sun through the clouds and with a remarkable degree of accuracy. They used a piece of spar that was recently recovered from a British shipwreck from 1592.

In the laboratory, Ropars and his team struck the piece of Iceland spar with a beam of partly polarized laser light and measured how the crystal separates polarized from unpolarized light.

By rotating the crystal, the team found that there’s only one point on the stone where those two beams were equally strong—an angle that depends on the beam’s location.

That would enable a navigator to test a crystal on a sunny day and mark the sun’s location on the crystal for reference on cloudy days. On cloudy days, a navigator would only be able to use the relative brightness of the two beams.

The team then recruited 20 volunteers to take turns looking at the crystal outside on a cloudy day and measure how accurately they could estimate the position of the hidden sun.

Navigators subdivide the horizon by 360 degrees, and the team found that the volunteers could locate the sun’s position to within 1 degree.

Even after the magnetic compass was invented in Europe in the 1300s, the feldspar was still an important navigational tool, hence its presence on an Elizabethan ship a full four centuries after the end of the Viking era. The study found that even a single cannon from the shipwreck interfered with the compass by as much as 90 degrees. Therefore they couldn’t rely on the compass data alone. If the sun was obscured, a sunstone was crucial to avoid drastic navigation errors from a magnetic compass on a ship laden with cannon.

You can see the neat double refraction effect of Iceland spar in this video:

[youtube=http://www.youtube.com/watch?v=yv5kkBCz78k&w=430]

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$1,000 reward offered for stolen 1795 Spanish cannon

Friday, November 11th, 2011

On the night of November 2, a Spanish bronze cannon from 1795 was stolen from a suburban Detroit business and its owner is offering a $1,000 reward for any information leading to its recovery. Matt Switlik, cannon collector and expert on historic field artillery, had brought the cannon to the Edston Plastic Company in Romulus, Michigan, to have a plastic replica made for a museum to use as a donation container.

The thieves were looking for a far more pedestrian haul of easily sold power tools and scrap metal. They made off with 20 of the former and several 200-pound boxes of aluminum. The cannon was hidden in the back under some racks and a coffin blanket. The thieves stumbled on it entirely by accident when they rolled out a coil of wire.

The cannon was cast in Seville in 1795. The crest of King Charles IV of Spain is engraved on it, as is the date, a serial number of 3610 and markings indicating it was made from copper from Mexico and from the Rio Tinto government mines in southwestern Spain. The 2.6 inch caliber weapon is 42 inches long, weighs 225 pounds.

Matt Switlik purchased it as part of a matched pair in 1974 from Inez Bandholtz, the widow of Maj. Gen. Harry Hill Bandholtz who acquired the cannons in the Philippines during the Spanish-American War and brought them back to Michigan when he retired from the Army after World War I.

The cannon is far too identifiable to be sold to collectors, so if the thieves do anything, they’ll try to sell it for scrap. The $1000 reward is double what they would get for the scrap value of the copper alone.

Switlik, a historian who collects cannons, paid $1,000 for it nearly four decades ago and now values it at about $12,000. He’s getting word out that his cannon was stolen to collectors across the country and sent an e-mail to 600 people Tuesday.

“As a stolen piece, it’s not worth anything,” said Forrest Taylor, owner of www.cannonsonline.com based in Maryland. Taylor buys, sells and reproduces cannons and said collectors will know Switlik’s cannon was stolen if they come across it.

Taylor also said he believes that the cannon’s actual value may be closer to $20,000.[…]

“I’d sure like my cannon back,” Switlik said. “The other one is lonesome.”

The Romulus police are investigating leads from the crime scene and looking for surveillance video any neighboring business might have. Anyone with information about the cannon should contact the Romulus Police Department at (734) 941-8400.

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