Thursday, 6 December 2012

I must go down to the seas again, to the lonely sea and the sky, And all I ask is a tall ship and a star to steer her by,

Click here to read the whole poem, one of my favourites - Sea Fever - John Masefield (1878-1967) (English Poet Laureate, 1930-1967).  Carrying on from my last blog dealing with our need to know the time, what is the connection between tall ships, stars and accurate time keeping?  I found this out when when I visited the National Maritime Museum Greenwich.
Increasing voyages of exploration and commerce meant that precise navigation became essential. The method used by Christopher Columbus  - Dead Reckoning- just wasn't good enough nor was Celestial Navigation and Sight Reduction Navigation using stars, the moon and sun to work out your position in latitude. In order to navigate accurately you needed to know where you were in both latitude (North to South) and longitude( East to West). Latitude was relatively easy to determine, if you knew the coordinates of a celestial object, the position of the object in the sky, the local sidereal time, apply some spherical trigonometry then you can determine your latitude.

A Sextant
 Used to measure the angle between any two visible objects. Its primary use is to determine the angle between a celestial object and the horizon which is known as the object's altitude.
Longitude was a more difficult problem. Initially longitude position was determined by the positions of the Moon but the lines of longitude differed between countries and charts.  In 1675 the Royal Observatory was established at Greenwich, England and here accurate data on the Moon was slowly accumulated. In 1767 the publication of English Nautical Almanac eventually led to the universal adoption of the meridian of Greenwich as the prime meridian, i.e. a line of longitude, at which longitude is defined to be 0°. The next step was to have a reliable way to compare the time where you were, to the time at the prime meridian, an hour is equal to 15° of longitude, you couldn't rely on the Ship's Boy turning the sand glass. Even the most reliable pendulum clocks of the time were unable to cope with the movement of the ships, changes in temperature and humidity. In 1714 this led to the launching of a competition by Act of Parliament, with a  £20,000 prize, to be the first to construct a marine chronometer precise and accurate enough to  provide longitude to within half-a-degree (2 minutes of time).
Stepping on the the podium in first place was Lincolnshire carpenter and self-taught clockmaker John Harrison (read here about his struggle with the Board of Longitude to actually be awarded the full prize money, it took the intervention of the King and another act of parliament).

John Harrison's Marine timekeeper, H4 completed in 1759 with its very stable, high frequency balance,
it proved the successful design. It was based on the design of a watch rather than a clock.

His chronometers worked at sea! Captain James Cook took K1 a replica of H4 with him on his sea faring expeditions.

Click here to read  in more detail about the development of Navigation.

Visit the museum in Greenwich to see John Harrison's chronometers, if you want to see one of his early Clocks or his paper drawing of the movement of H.4, go to the Clock Makers Museum at the Guildhall, City of London, where there is a wonderful collection of early clock, watches and sundials. Entrance is free!

Friday, 23 November 2012

I don't wear a watch. I want my arms to weigh the same.

The words of Harry Hill. Anyone else out there not wear a watch? My husband has a bit of a collection, the most precious both in material and sentimental value is a watch left to him by his grandfather. Harvey Lewis was born in the 1890's, he grew up in the East End of London where he trained and qualified as a Ladies Master Taylor. Just before the WW1 he married and moved to North London.  During the war he was a bit of a wheeler dealer then after he established a flourishing tailoring business which he ran from his front room. The success of this lead to him rewarding himself with a Rolex Zebra Striped 9K Gold Prince Brancard wristwatch.
The Rolex Prince Watch
On October 1, 1927, the patent number 120849 was granted for a movement that was to be named Prince. The main advantage of the movement design was that, by placing the winding barrel and the balance at opposite ends of the watch, they could each be much larger. The Rolex Prince watch proved to be one of the most accurate wristwatches made. The accuracy comes from the very high quality balance wheel, which most unusually for a wristwatch used solid gold screws to add extra weight and therefore, momentum. The watch also had a very high quality finish to the whole escapement, even the wheels. All of these efforts went to ensuring the accuracy of the Prince. Rolex Prince with two dials is often referred to as a ‘doctors watch’ or ‘duo-dial’. The strap is a replacement however it still has the original gold plated pin buckle. The watch was given to Max, Harvey's only child, who hardly wore it and kept it in a safe for many years before passing it on to his younger son. Feel tempted to buy one? click here to make an offer.
Harvey also left some labelled coat hangers and wonderful wool fabrics that have since been made into suits.

Watches have become a fashion accessory and for some a status symbol, others - just need to know the time. Which has made me wonder when man first had the need to tell the time, just going to google that question.......It seems that our forebears invented methods to divide the day or the night into different periods in order to regulate work and for ritual/religious festivals. The lengths of the time periods varied greatly from place to place and from one culture to another. An Egyptian sundial from about 1,500 BC is the earliest evidence of the division of the day into equal parts, but a sundial couldn't be used at night so other methods such as water clocks (clepsydra), oil lamps and candle clocks were developed. Click here to read about sundials in detail and make your own - all very mathematical.
In 27 AD Hipparchus of Niceae, working in Alexandria, proposed dividing the day into 24 equinoctial hours. Equinoctial hours, are based on the equal length of day and night at the equinox, split the day into equal periods. However, ordinary people didn't adopt this for well over a thousand years. (The conversion to equinoctial hours in Europe was made when mechanical, weight driven clocks were developed). The division of time was further refined by another Alexandrian based philosopher, Claudius Ptolemeus, who divided the equinoctial hour into 60 minutes, using by the scale of measurement of ancient Babylon.
The first clock escapement mechanism appears to have been invented in 1275 and subsequently watches evolved from these portable spring-driven clocks. More detail to follow in future blogs.
If you get a chance to visit the The science museum you can see a collection of early watches there.

Friday, 9 November 2012

I cannot promise you a world, Can't afford any fancy things, I cannot buy you diamond rings, No string of pearls

Russell Thompkins Jr of the Stylistics claiming his poverty prevents him giving his love any gifts. Sing along to the karaoke version here!

Really that's a poor excuse for being thoughtless. Jewellery doesn't have to have financial value to have great sentimental value attached to it. That's one of the real pleasures of giving and receiving jewellery.  Of all the pieces that I have been given, it is one of no value that shows great thought behind it; making its worth priceless to me.

As mentioned in my earlier blogs, my compulsion to pick up objects on the beach saw me, on the Andalusian coast earlier this year, picking up small fragments of household tiles. They had been worn smooth by the sea, one side was terracotta, the other glazed in white. I brought some home and there they languish with the inactive shell collection.
My 26th wedding anniversary arrived and my husband gave me one of these tiles. He had spotted a tile piece on the beach that had been formed into the shape of a heart and had hidden it in his pocket. Once home he had drilled it and threaded cord through and had the back engraved.
I enjoy wearing it, not for its value but for the associated memory and the thoughtfulness of the gesture.
My Tile Pendant from a beach near Nerja, Andalusia, Spain.

The same with inherited jewellery, it doesn't have to be of large value to be enjoyed and to invoke memories of the relative to whom it belonged. A wonderful thing about jewellery is that it is enduring, it can be repaired, remounted even re-designed so that future generations can keep wearing whilst appreciating the history of a family piece.

A modern brooch made using stones from unworn rings

My friend had the stones from several of his mothers rings made into this unique modern brooch. The value of the gold in the old settings was more than sufficient to pay for the new piece and he also received a cheque for the remaining value in the gold scrap. Brilliant!

Don't leave your jewellery abandoned in hidden places, dust it off, repair it, redesign it. Find out about the person it belonged to, any pictures of them wearing the piece? when and why it was given? Wear it with pride and enjoy sharing the story behind the jewellery.
The stones were taken out of this old out ring that wasn't being worn, re-polished
and then set into this new contemporary design. What an improvement!
Do you have any jewellery with a romantic story associated with it? Got any family pieces with an interesting history? share them with me here, I am curious to read  them.

Saturday, 3 November 2012

Next to my own skin, her pearls. My mistress bids me wear them, warm them, until evening when I´ll brush her hair.

The opening lines of Poet Laureate, Carol Ann Duffy's poem called "Warming Her Pearls"
and one way to judge if pearls are natural, cultured or synthetic. (Read or listen to the full poem here)

(Dame en dienstbode)
c. 1666-1667
oil on canvas
The Frick Collection, New York
Pearls were an important status symbol of this age and they held for the educated Dutch art lover, a number of associations. In no other painting by Vermeer are there so many pearls. The mistress wears a pair of oversized drop earrings (artificial), a pearl necklace and strings of pearls in her hair.

When you first put them on natural and cultured pearls feel cold on the skin, they do warm up as you wear them. I can't find an explanation of why they are so cold but suspect it's to do with the poor conduction of heat. Synthetic pearls don't feel cold, unless they are made of glass. So another test is to rub the pearls on your teeth; natural and cultured pearls feel rough, synthetic ones feel smooth.
If the pearls are unstrung rub two gently together; if they offer resistance they are real or cultured pearls. If they feel smooth they are synthetic.

X-ray is the surest way to identify the type of pearl as it can differentiate between natural and cultured pearls - if you want to go to such lengths. Natural pearls are sold by weight (carat of pearls) while cultured pearls are sold by size (diameter of pearls).

Uniform natural pearls are extremely rare and very expensive.
The Baroda Pearls

In 1943, Maharaja Pratapsingh Gaekwar made headlines by marrying Sita Devi, his second wife. Referred to as “The Indian Wallis Simpson” by the Western media. Sita Devi received the jewels from the Baroda treasury including a seven strand natural pearl necklace.
The largest and most perfect pearls from the necklace were made into two large strands, consisting of sixty-eight graduated pearls, measuring approximately 9.47 to 16.04 mm, all matched in colour, lustre and shape and joined by a cushion-cut diamond Cartier clasp. In 2007 these were auctioned by Christies, along with matching brooch, earrings and ring, for the record sum of £4.5 million.

Queen Elizabeth of Hollywood and Queen Mary1st of England
both wearing La Peregrina
La Peregrina is one of the most famous pearls in the world. Its history spans almost 500 years and it has passed from the African slave who found it at Pearl Islands in the Gulf of Panama to European Kings and Queens. Until recently, the pearl belonged to Elizabeth Taylor bought for her by Richard Burton as a Valentines gift - lucky girl!  She had it mounted on a diamond and ruby Cartier necklace. After her death it was auctioned at Christie's in New York, the bidding reached £7.1m. Watch the auction here.

Look after your pearls, they should be stored wrapped in soft cloth or in a soft-lined container to prevent them being damaged from harder items of jewellery.
Apply perfume, hair spray and other cosmetics before putting on your pearls to reduce the effects of these products on your pearls.
After wearing your pearls, wipe them with a soft damp cloth to remove any traces of cosmetic products or body oils.
The threads used to string the pearls are liable to stretch and break, be aware of this check the strands and get them restrung as necessary

Monday, 15 October 2012

Dear as the wet diver to the eyes 
Of his pale wife, who waits and weeps on shore, 
By sands of Bahrain in the Persian Gulf;
 Plunging all day in the blue waves; at night, 
Having made up his toll of precious pearls,
 Rejoins her in their hut upon the shore.

the words of Sir Edwin Arnold (journalist and poet 1832 -1904) using his poetic license to write a job description of a pearl diver.

I hardly know where to begin so much is written about pearls, from the wonderful imaginative myths of the ancients to the duller pragmatic accounts. I know I prefer to hear that the water that dropped from Venus’ body; as she emerged from the sea, was so affected by her beauty that it formed into Pearls. Slightly more romantic than: When a mollusc is invaded by a parasite or a foreign object that it can't eject, a process known as encystation covers the irritant in successive, concentric layers of nacre; a pearl is eventually formed.

The process of natural pearl formation is so rare that only 1 in 10,000 shells may produce a gem-quality pearl. As the layers of nacre tend to maintain the irregular shape of the original irritant, most natural pearls are irregularly shaped. Natural pearls which are round or spherical in shape are even more rare.

This baroque drop-shaped natural pearl weighing 239.7 grains (59.92 carats) 
 was sold for just under £160,000 at a Christie’s sale.

In the early 20th century demand for pearls led to Japanese scientists developing cultured pearls. By planting a polished bead made from special mussel shell along with a small graft of mantle tissue from a live oyster; the molluscs produce pearls. A typical fresh water mussel can produce up to 16-32 pearls at a time whereas the saltwater oyster can only produce 1 or 2 pearls at a time. Cultivation takes from two to four years depending on conditions, variety and whether it is a fresh or salt water mollusc.
My cultured pearls - I do  have matching earrings -
 I can't remember where I put them though....

Imitation or simulated pearls are entirely manmade. A bead is dipped into a mixture based on crushed fish scales known as "essence d’orient". This coats a bead and produces an imitation pearl. Other lower quality imitations may be made from plastic or ceramics. These are used for costume jewellery and provide an inexpensive way of imitating cultured pearls.

In my next blog, identifying "real" pearls, looking after pearls and more about mother of pearl.

If you really do want to read in detail about pearls take a look at this wonderful book written in 1908 The Book of the Pearl (available to read online).

Wednesday, 10 October 2012

She sells sea shells continued

Looking through my jewellery I found I had other items that had originally been part of or produced by a living organism in the sea - a pendant made from abalone, coral earrings and a pearl necklace.  
my abalone pendant
My pendant made from abalone.
An abalone
Abalone is a common name for any of a group of small to very large edible sea snails. Sizes vary from 20mm to 200mm (or even more). The flesh of an abalone is considered a delicacy and can be consumed raw or cooked. If you are curious, here is how to prepare your abalone for consumption 

The inner layer of an abalone shell.
I am more interested in the the colourful highly iridescent thick inner layer of the shell, known as nacre or mother of pearl. This is produced in layers to protect the soft flesh of the snail being damaged by parasites or debris. The offending body gets trapped in the layers and can form a blister pearl that is attached to the shell or a free pearl ( see below).

This beautiful shell has long been used in jewellery as well as in other decorative items.
Abalone nacre used to emulate the
iridescence of a dragon flies wings

The very skilled use of abalone nacre used
as a decorative infill on this chinese table.

Abalone rarely produce pearls when they do, due to their internal structure, the pearls are often unusual shapes. The most common shape resembling a horn or sharks tooth. Abalone pearls can be very large - over 120mm in length. The value of an abalone pearl is determined by colour, lustre, shape, weight and size. These pearls are so rare that it takes an estimated 100,000 abalone harvested to produce one.

Over-fishing and poaching have reduced wild populations to such an extent that farmed abalone now supplies most of the abalone meat consumed. 
Scientists have found a way to recreate artificial nacre, this has its uses in technology read more here.

Abalone was revered among the native American Navajo, as one of the Navajo's four sacred stones; abalone plays a significant role in many of their myths.

Monday, 8 October 2012

She sells sea shells on the sea shore, part 1

Sanibel Island, USA where the unique angle of the island catches incredible amounts of sea shells on the
sea shore and where I have spent hours obsessively picking up shells to collect with the intention to make "something " from them.
I was wondering, what was the age of oldest jewellery discovered. Thinking it would be made from a metal, I was surprised to see they are beads made from shells. The shells come from a marine mollusc known as Nassarius, which is a type of whelk. Chemical and elemental analysis of sediments stuck to one of the shells showed that it came from ground layers dated to 100,000 years ago, Middle Stone Age. The pea-sized shells all have similar holes which would have allowed them to be strung together into a necklace or bracelet. Researchers believe they were probably selected for their size and deliberately perforated with a sharp flint tool.
The ancient shell beads.

Two of the ancient beads come from Skhul Cave on the slopes of Mount Carmel in Israel. The other comes from the site of Oued Djebbana in Algeria. Where they were discovered was never that close to the sea this means they were transported by people to these locations.
Whether they were worn for decoration, to symbolise status or to ward off evil; we can only speculate.
Here in the Technological Age, 100,000 years later, I have my own necklace made from Nassarius, I wear it purely for decoration although if it does ward off the evil too, thats fine by me.
A testimony of the enduring charm of jewellery - however simple.
My whelk necklace. 
"It is perhaps a more fortunate destiny to have a taste for collecting shells than to be born a millionaire"  Robert Louis Stevenson - 1850

In the past shells were used as money. They were particularly useful because they could be strung in long strips of proportionate value or used to provide a single unit value in  exchange. Relative scarcity of the type of shell used or the way the shell was fashioned determined its value. Cowrie shells were the most common shell money.
Go to this the British Museum page to read more.

Even today there are avid dealers of shells who are are using shells as a way of accumulating wealth. Take a look at this young entrepreneur.