Carmarthen's Connection with the Optical Telegraph

The optical telegraph must have been sufficiently familiar to Charles Dickens's readers for him to describe Mr. Dick in David Copperfield as "making a veritable telegraph of himself by his gesticulations to Miss Betsy Trotwood".

Communication over great distances has been possible for thousands of years, by smoke signals, drum beats and, particularly, light beacons. Greeks, Romans, Carthaginians and many others had their own methods of relaying news. However, they were unreliable at best and very susceptible to becoming garbled in transit. The optical, or visual, telegraph was invented in the late 17th century but not until a century later did a practical form come into use, on the threshold of the electric era.

Robert Hooke, the great physicist and contemporary of Newton, delivered a comprehensive plan for visual telegraphy to the Royal Society in 1684 but his method was never put into practice. The Frenchman Claude Chappe, who was born in 1763, considered the possibility of an electric telegraph but electricity was at too primitive a stage. He tried a number of impracticable ideas for a visual telegraph and eventually came up with an elaboration of the semaphore principle, which was accepted by the National Convention in 1793. France was at war with most of her neighbours and the new telegraph promised rapid communication between Paris and the military commanders in the field. By 1894 a line of 15 stations connected Paris with Lille and by 1810 with Venice and Amsterdam. Each station consisted of a post supporting a wooden beam which pivoted at its mid-point. Pivoted at either end were shorter arms. A system of ropes and pulleys allowed 196 combinations. By 1844 25 French cities were connected through 500 stations and a message could be sent 500 miles from Paris to Toulon in 20 minutes. Although successful, the system was very expensive to maintain.

The Admiralty, very aware of the value of this system, needed a similar one. The system it adopted was devised by Lord George Murray, who later became bishop of St. David's. Three pairs 0f rectangular shutters in a vertical frame could be rotated independently about a horizontal axis. When a shutter was vertical it could be seen at a distance but in the horizontal position it was invisible, an early use of binary code. 64 combinations were available. A line from London to Deal was opened in 1796 and to Portsmouth in 1798, Plymouth in 1896 and Yarmouth in 1808. A short message could be transmitted over 72 miles to Portsmouth and an answer received in 15 minutes. To achieve these speeds another modern tool was used, data compression very similar to text messages today: "H.M.S. ROYAL SOVEREIGN ANCHORED AT SPITHEAD YESTERDAY SAILING FOR PLYMOUTH TOMORROW" became "RSOV ANCHOR SPITD YESDA SAIL PLYTH TMRO".

Following the signing of the Peace of Paris in 1814 all four lines were closed. They would have been very useful following Napoleon's escape from Elba but there was insufficient time to get them working again. After Waterloo plans were made to resurrect the system using an improved apparatus devised by Rear-Admiral Sir Hope Popham. This consisted of two semaphore arms on a mast, allowing 48 combinations. A line to Chatham was opened in 1816, was transferred to Plymouth in 1822 and dropped before it could be opened because of the impending installation of an electric telegraph following the London and South Western Railway route. The first commercial optical telegraph system was installed between Holyhead and Liverpool in 1827.

Lord George Murray was Bishop of St. David's from 1801 to 1803. During his episcopate the Palace at Abergwili was repaired and improved. It was probably Murray who added an east wing, now the archaeology gallery, replacing a length of curtain wall or cloister walk, which linked the north and south wings. Murray also placed the main entrance in his new east wing, so that the magnificent sweep of the river could be viewed by visitors arriving at the front door. Unfortunately the river changed course in during the great flood of 1802 and disappeared over to the other side of the valley, where it remains today, leaving only the Bishop's Pond as a reminder of its course. He was responsible for adding the bay windows and gothic detail to the building and appears to have landscaped the grounds and added the ha-ha as part of the improvements. He may well have involved John Nash and Humphrey Repton in the work as both were in the area and working in the diocese. Following Murray's reign, the building was once again left to gradually fall into a state of disrepair, so that by the time John Banks Jenkinson became Bishop in 1825, it was in need of substantial investment. Jenkinson changed the entrance back to the west front, where it is today.

Thanks to Rhodri Young for the information in this article.

A supplementary article on the Bishop appeared in the December Friend and is published below.

In the August issue we published an article by Rhodri Young on the telegraph system invented by Bishop Murray. Since then Rhodri, a volunteer who does a great deal of research for the Museum staff, has come across the following article by George Eyre Evans, who, among many other activities, started our museum's collections.


Next Monday's Opening of Carmarthen's New 'Phone Exchange

The Lord Bishop of St. David's will, - so reads the card inviting me to the ceremony, -"open the new automatic Telephone Exchange at Carmarthen Post Office."

This gives me to think how appropriate is the choice of opener. Few of my fellow-citizens probably know that one of the Bishop's predecessors, Lord George Murray, who sat on the stool of St. David's from 26th December, 1800, until his death on 3rd June, 1803, was a recognised authority on Signalling, Semaphores and Telegraphs.

When, in 1864, my father (died 1902 at 90) was called by the governing body to occupy the chair of Hebrew at the Presbyterian College, Carmarthen, he was minister of an ancient congregation in the far west of Devon, and there was no vacant house in Carmarthen to which he could take his wife and young children. Bishop Thirlwall offered his young brother Hebraist Ty Mawr, Abergwili, and there he and his family lived for a while. This, by the way, enabled me to be sent to the village National School, a fact of which I am still proud and grateful. There were then living in Abergwili a few aged folks who remembered having "heard on" Bishop Murray, and one who gave my father memories of the semaphore apparatus the bishop erected in the Palace grounds. The Bishop had a large family who took it in turns to work the ropes and to signal to him in his study, One wonders what the Bishop of St. David's in 1985 will be called upon to do: certain it is the call will be answered in the spirit in which the Bishop on Monday next will say, "Hello, the Bishop calling."


The Parade, Carmarthen. 30th May 1935

From the Carmarthen Journal May 31 1935