Showing posts with label Science. Show all posts
Showing posts with label Science. Show all posts

Friday, 26 April 2013

John Whitehurst - clockmaker, scientist, geologist

Those of you who have followed my 'blogland' journey for a while will be well aware that my roots are in Derbyshire, and that I have a fascination for the enlightenment period that took place there in the 18th century. In pursuit of that interest I now bring you Lunar Society member and clockmaker extraordinaire - John Whitehurst.
via BBC paintings
John Whitehurst - 1713 - 1788 - painted by Joseph Wright of Derby
It is exactly three hundred years ago this month that John Whitehurst was born in Congleton, Cheshire, close to the Derbyshire border, the son of a clockmaker. He received only a slight formal education and was taught clock-making by his father; his father also encouraged and fostered his pursuit of geology whilst they took long walks in the Derbyshire Peak District.
He moved to live in Derby in 1736 where he became one of the foremost scientists of his day, father of modern geology and founder member of the Lunar Society along with Erasmus Darwin, Josiah Wedgwood, James Watt, the painter Joseph Wright  and others.
In Derby he established a very successful business not only making clocks, but fine scientific instruments. He made thermometers, barometers, and philosophical instruments. He was consulted on almost every undertaking in Derbyshire and neighbouring counties in which skills in mechanics, pneumatics and hydraulics were required.
Whitehurst pioneered the method of using a single source material to construct the workings of a timepiece. This helps reduce variations in performance caused by temperature and humidity. It was so successful that it has never been bettered. This technique may have come about following a challenge he was presented with by the founding father of America, Benjamin Franklin. Franklin asked him to design a clock that used fewer materials as there was a drastic shortage of raw resources at that time across the Atlantic. Whitehurst met Franklin's  challenge, and in due course Franklin signed the documents that founded the United States of America as Whitehurst's clock ticked gently away in the background. 
In 1774 Whitehurst moved to London to take up a post at the Royal Mint. London is where he spent the rest of his life exploring different avenues of science and where in 1779 he was elected a member of the Royal Society.
In 1783 he was sent to examine the Giant's Causeway and other volcanic remains in the north of Ireland.
He had already published his theory on geological strata in 'An Inquiry into the Original State and Formation of the Earth'. This eventually facilitated the discovery of valuable minerals beneath the earth's surface. 
It is thought that Whitehurst was the model for Joseph Wright's famous painting of A Philosopher Lecturing on the Orrery.
 Derby Art Gallery - via BBC paintings
Whitehurst placed such heavy demands on his commitment to learning and research that he tired himself out and impaired his health. Even so, he lived to be 75 years old - a good age for that period. He was married but there were no surviving children to carry on in his footsteps.

Thursday, 28 June 2012

Fossil Sea Urchins

This is the third guest post done by J
Sea Urchin and Sand Dollar from our collection
Who, amongst us, has not been excited at discovering the skeleton of a sea urchin. Whether found whilst exploring a rocky pool, or in a seaside souvenir shop, the aesthetic appeal is immediate. We take it home and place it in a prominent place so that its form can continue to be a source of pleasure.
The taxonomic class into which the sea urchin falls is "echinodermata", an invertebrate family of 6,000 living species including starfishes and sea lilies. Some 13,000 extinct species of echinoderms are also known.
The remnants we find of a sea urchin (scientific name: "echinoid") on the beach is the calcareous skeleton with its distinctive five-pointed pattern.
My layman's geological and anthropological interest in sea urchins has been triggered by an article in the June 2012 edition of the magazine "Geoscientist" published by the Geological Society of London, of which eldest son is a Fellow. My granddaughter's recent commencement of studies at Oxford University in archaeology and anthropology has also reinforced my interest. 
The article is entitled "Prehistoric fossil collectors" and is written by Ken McNamara, a senior lecturer at Cambridge University.
The article throws light on the collecting of fossil sea urchins, a practise known to date from as long ago as 400,000 years, when a human ancestor (Homo heldelbergensis) shaped a flint tool in which a fossil sea urchin was incorporated.
courtesy Ken McNamara
The author describes the discovery in the English Chiltern Hills in 1887 of a grave containing the skeletons of a young woman and child. Also in the grave, dating to the Bronze Age some 4,000 years ago, were hundreds of flint balls each carrying the fossilised five-pointed image of a sea urchin. As McNamara puts it "a cornucopia of fossil sea urchins seem to have been buried very carefully with the bodies in their chalky grave".
courtesy Ken McNamara
There are numerous other instances of fossil sea urchins discovered in neolithic barrows (i.e. burial mounds), and in graves set-down as recently as Anglo-Saxon times, which took place over a wide geographical area. The question McNamara attempts to answer is "Why?".
courtesy Ken McNamara
The author speculates that the fossils could have had some great spiritual significance, perhaps in ensuring the passage from this life into the next. Later practises, for example in Celtic cultures, of placing fossil sea urchins on window sills or near to doors, were part of a folklore associated with the bringing of good luck. They are also linked with Norse mythology through the god Thor in which they were called "thunder stones" thrown to earth by Thor. Thor was the peasants' god, who gave them protection; so stones were strategically placed to ward off lightning strikes and to protect the house from evil.
courtesy Ken McNamara
Fossilised Sea Urchins around a window at St Peter's church, Linkenholt, Hampshire
One of the most striking fossil Sea Urchins found was at Heliopolis, Egypt which had hieroglyphs inscribed on it in about 1500 BC. They tell the name of the priest, Tja-nefer, who found it in 'the quarry of Sopdu', a god sometimes known as the 'Morning Star'. McNamara links the five-rayed star on the fossil with the extensive use of the star symbol in Egyptian burial chambers; hence a spiritual connection with the pharaohs and their funeral rites.
He suggests that the myriad modern-day usage of the five-pointed star symbol may have evolved from this usage in ancient times.
There is a lot more fascinating information in Ken McNamara's article, and I would recommend it to those whose interest has been sparked. He is also author of a book "The Star-crossed Stone" published by University of Chicago Press.
Incidentally, fossil Sea Urchins continue to be turned up by the plough in flinty fields, such as on Salisbury Plain, and are still collected to this day! 
Personally, I believe that the aesthetic appeal of both the skeleton and the fossils probably explains, more than anything else the human fascination with these objects. 
First guest blog by J and second.