Time is what prevents everything from happening at once. ~John Archibald Wheeler

Continuing developments to the mechanisms that drove clocks did eventually lead to increasing accuracy in time keeping.
The invention of the mainspring lead to the development portable timepieces. The inventor of the mainspring is unknown but references to 'clocks without weights' and two surviving examples show that spring powered clocks appeared in the 15th century Europe. The mainspring is a flat ribbon of steel wound in a coil and attached to the gears of a clock. When the mainspring is wound up and released, it drives the gears as it unwinds.
These clocks and watches gained or lost time in such unpredictable amounts that no one thought of using them to tell the time they were seen more as ornaments. These portable clocks were the first timepieces that the more wealthy people could own they weren't worn on the body.

The First Spring Driven Clocks only had an hour hand. The face was not covered with glass. 
The movement was made of iron or steel and held together with tapered pins and wedges,
 screws weren't used till after 1550.

Some sources credit Peter Henlein (1480-1542), a German locksmith  and watchmaker working in Nuremberg as the inventor of the watch as he was a well known craftsman of early "clock-watches" (taschenuhr), ornamental timepieces worn as pendants which were the first timepieces to be worn on the body.
Improvements to the design of the escapement and the methods used to drive these portable timepieces were continually being made.
Want to buy a replica click here

When Christiaan Huygens made the first attempt at a marine chronometer in 1673 in France, he used a balance wheel and a spiral spring for regulation. A balance spring, or hairspring, is attached to the balance wheel, it controls the speed at which the wheels of the timepiece turn and so the rate of movement of the hands. Huygens spring was an improvement on the straight spring invented by Robert Hooke, unfortunately his clock remained inaccurate at sea.

Drawing of one of his first balance springs, attached to a balance wheel, by Christiaan Huygens.
Published in his letter in the Journal des Sçavants of 25 February 1675.

John Harrison eventually created his accurate marine chronometer H4 based on the design of a large pocket watch (his design was too complicated to be replicated on mass).
Pocket watches continued to evolve, the box-like shaped was replaced by more rounded and slimmer cases.
Thomas Mudge's lever escapement (1754) was a great leap forward and is still used in mechanical watches, in a modified form, today.  

Queen Charlotte's Lever Watch and Pedestal
Probably acquired by George III for Queen Charlotte in 1770
(Backplate signed Tho Mudge / London)

Queen Charlotte's Lever Watch and Pedestal made in 1770, currently part of the Royal Collection, appears to have been the first timepiece to use this important development, the earliest known example of the lever escapement. Also, this was the first pocket watch to have an automatic device for compensating changes in temperature.
Still at this time watches were still being produced in small batches in small workshops and owned by the wealthy.
In the 18th century jewels were used as bearings, diamonds became part of some pocket watches and oil was used to lubricate and smooth the movement of the watch parts.
The 1850's saw the introduction of machine made watches, made in Switzerland and the United States, these were eventually produced at such low prices that by the end of the century ordinary people could afford a watch.
Read this interesting story about President Lincolns Pocket Watch
The beginning of the twentieth century saw the introduction of the wrist watch, still seen as a piece of jewellery just for women, but following its successful use in service during the First World War (1914-18), increasingly among men.
More about the development of wrist watches in a future blog.

"knowing the sky, knowing your relationship with the sky, is the centre of the real answer to knowing what time it is." Tom Wujek

I did say I would write more about the development of clocks and watches. Researching this subject has been very interesting and there is so much information that I have condensed into an outline here.
The ancient Greek, Roman, Chinese and Islamic cultures all developed similar methods to mark the passage of time, oil lamps, candles, sundials, water clocks, merkhet, astrolabe. What was clear that these ancient civilisations had some amazing geniuses (or genii for the correct Latin spelling) that were able to use their knowledge of mathematics and astronomy to develop some wonderful instruments; to tell time, to be used as calendars and to track the movements of the sun, moon and stars, for use in astronomy and astrology. Sadly through the passage of time - and wars - these inventions were lost and we had to start again in the West.
Some (not all) of the greats in Time Keeping (click the name to read more) include:
Ctesibius (born in Alexandria around 300 BC) whose improvements to the water clock resulted in a time-recording device whose accuracy could not be improved on for over 1,500 years.
Hipparchus of Nicaea (born in 190 BC) who accurately recorded  the movement of the sun, moon and stars and other planets and developed trigonometry and constructed trigonometric tables and solved several problems of spherical trigonometry
Andronicus of Cyrrhus (born 100 years BC) whose Horologium (time keeping piece) called the Tower of The Winds still stands today. This public clepsydra (water clock) was driven by a stream flowing down from the Acropolis.

The Tower of the Winds, Athens.

Hypatia (born in Alexandria 370 AD) credited with creating a geared astrolabe and a planesphere.
Since ancient times as a kind of analogue computer know as an astrolabe has been used to find the time during the day or night, find the time of a celestial event such as sunrise or sunset and as a handy reference for teaching astronomy. The celestial sphere, containing  the astronomical objects - moon, sun and stars, is projected on to the plane of the astrolabe (stereographic projection). The moveable componants are lined up to correspond to the users current position and once set, the entire sky, both visible and invisible, is represented on the face of the instrument.

Watch this short animation to see a demonstration.
Download an astrolabe app for your iphone here

The Clock at Hogwarts based on the design of an Astrolabe.

There is no one person responsible for the invention of mechanical clocks rather there were developments and improvements.
Original clocks were astrological clocks based on the design of the astrolabes. The Prague Astronomical Clock or Prague Orloj is a medieval astronomical clock. It was installed in 1410, making it the third-oldest astronomical clock in the world and the oldest one still working.

Prague Orloj

So how did we get from those astrological clocks and water clocks to perpetual movement mechanical clocks, it was the development of a mechanism called an escapement.
1280-1320 saw increasing references to clocks and horologes and existing water clocks being adapted to use falling weights to power them. The release of this power was controlled by the escapement. The earliest record of an escapement being used is in medieval China - Su Song incorporated a kind of escapement in his astronomical Clock Tower of Kai Feng (1088) but it was reliant on water to power it. The date of when an escapement was first used in a clock is unknown.The first clear drawing of an escapement was by Jacopo di Dondi and his son in 1364. It is estimated that escapements were being used in mechanical clocks  in the late 1200's. 

Verge and foliot escapement from De Vick clock, built Paris, 1379, by Henri de Vick

The first mechanical clocks were no more accurate than the best water-clock accuracy. However, overtime the improvements to the design of the escapement, the method of driving the mechanism and the materials used to make them lead to very accurate time pieces. Read in detail more here.
Click here to see the British Museums wonderful animated demonstration on how an escapement works.
Salisbury Cathedral has the worlds oldest mechanical clock, installed 1386, that still strikes the hours.
Next blog how watches developed for portable clocks.
If you are really interested in the subject and curious to see old clocks and watches click here to take a look at the Antiquarian Horological Society Website.

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!

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.

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.

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.

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)

JOHANNES VERMEER
MISTRESS AND MAID
(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.

Read here in more detail.

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. 

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).