George Bidder was born in Moretonhampstead, became famous nationally as a boy prodigy at mental arithmetic, was sent to study mathematics at Edinburgh University, and then entered the Civil Engineering profession just at the time when his skills were valuable in the enormous development of the railway system and the docks. He prospered (and  helped his Devon relatives to prosper), bought property at Dartmouth, and eventually retired there.

He is remembered in Devon chiefly as an infant prodigy, and his status as Civil Engineer and successful business man is forgotten.  The following brief account of his career, based on the biography “The Calculating Boy” by his great-great-grandson,  E.F. Clark,  MA,  MIMechE , is intended to restore the balance.


George Bidder was born in Moretonhampstead.  He was the third son of William Bidder, a stonemason, and Elizabeth Parker, whose family were also stonemasons. He had two elder brothers, William  (later a nonconformist minister) and John (a stonemason, like his father). John taught him the numbers from the face of his watch and explained how to count up to one hundred, but that was all.  However George loved numbers, worked out the multiplication table for himself while playing with marbles, conkers or shot, and delighted in doing sums in his head.  His skill was first noticed when, after he was in bed, he heard his elders trying to work out what they would get from the butcher for their pig,  and impatiently shouted the correct answer down the stairs.

He often sat in the blacksmith’s shop across the road, and soon found that he was rewarded by the bystanders for showing off  his skill at simple sums.  His ability to do elaborate multiplication sums grew with practice. He found it easy to hold large numbers in his head, and visualised them although he had not been taught to write them down.

When George was seven Jacob Isaac, the local  Baptist minister, who also ran a school, examined him and reported that, although he had difficulty in reading, and did not know the relationships between feet and inches or days and years, he had no difficulty in doing sums involving these quantities once they were explained to him. 


Before long George’s father found it profitable to exhibit him as “The Calculating Prodigy” at fairs and shows, going further afield as his reputation grew.  Advance notice would be given of his appearance in some inn or hall, and a charge made for admission. In this way he visited, among others towns, Brighton, Cheltenham, Tewkesbury, Dudley, Worcester, Birmingham, Oxford, Cambridge, Norwich, Great Yarmouth and of course London. In the course of this,  in the winter of 1816-7, he was invited to answer questions by Queen Charlotte, which were duly reported and added to his fame. The problems set were wrapped up verbally in the way usually used in those days, but he had no difficulty in reducing them to arithmetic, and once a new set of units had been explained to him he remembered the relationships between all the units.

The travel as a “prodigy” must itself must have been quite an education for a country boy, but in 1816 two gentlemen from Cambridge who saw his performance persuaded his father to let him attend school in Camberwell – his mother was enthusiastic, but his father less so.  However George had a year of regular schooling before going on tour again.  George does not seem to have resented this life – he remained a cheerful boy, quite willing to joke with questioners.


In 1819 George was exhibited in Edinburgh, and a new life started.  He attracted the attention of a group led by Sir Henry Jardine, who undertook his education in Edinburgh.  He spent a year with a private tutor and then attended classes in Mathematics and Natural Philosophy at the University.  His “prodigy” days were behind him, he became a normal student and made friendships which lasted throughout his life, notably with Robert Stephenson, son of the railway engineer George Stephenson.

Later, when George became prosperous, he repaid his debt to Jardine and Edinburgh by establishing a scholarship at Edinburgh University for a student of limited means, which he named the Jardine Bursary.

Sir Henry Jardine not only provided for George’s education, he also remained his mentor in his professional career until his death in 1851.   He found George a post in the Ordnance Survey as a trainee after he had finished at Edinburgh, and after five years in Scotland, George set off in 1824, at the age of 18, for Cardiff and then London.


George spent a busy time, based on London but travelling to carry out specific surveys, learning professional skills and making contacts which were vital to him in the next stage of his career.  After a year with the Ordnance Survey he moved into Civil Engineering as assistant to Henry Palmer, a former pupil and assistant to Thomas Telford.  With Palmer he worked on surveys for the London Docks and on several railway and canal surveys.  For a while in 1827 he also took part-time work as a clerk at the Royal Exchange Life Assurance office, to make more money to help his younger brothers.  His next work was as an assistant engineer with Walker and Burges, laying the granite tramway in the Commercial Road, and on the Brunswick wharf at Blackwall.

  In 1834 he formally joined his friend Robert Stephenson on work for the London & Birmingham Railway for a year, a time of intense activity.  The partnership and friendship between George Bidder and Robert Stephenson, later described by Stephenson as “the long and satisfactory private as well as professional friendship”, lasted until Stephenson’s death in 1860.

This was the beginning of the railway era.  In 1825 the Stockton & Darlington Railway had opened, with a steam locomotive driven by George Stephenson, and in 1829 the Rocket was designed by Robert Stephenson for the London & Manchester Railway.  Plans for new railways were mushrooming, and these needed accurate survey work and detailed costings to support the applications for Acts of Parliament to approve them.  Here was a new field for George’s talents, appearing before Parliamentary Committees – his surveying skills and prodigious ability at mental arithmetic made him highly effective in presenting his plans and spotting the errors in the plans of others, and he enjoyed the cut and thrust of  argument.  In fact it is said that on one occasion opposing Counsel  objected to his presence “because nature had endowed him with particular qualities that did  not place his opponents on a fair footing.”

Other railways he later worked on in association with Stephenson were the London & Blackwall Railway, the London-Brighton line (a plan which was not accepted), the Blisworth-Peterborough branch of the London & Birmingham, the Yarmouth & Norwich and Norwich & Brandon lines (designing the first swing bridge), the North Staffordshire, and the London, Tilbury and Southend.  In later years he made major contributions to the rationalisation of the East Anglian railways and the formation of the Great Eastern Railway.


The Electric Telegraph was a new invention, not yet commercially developed, when Bidder persuaded the London & Blackwall Railway to install the system as part of its management.  Later, on the Yarmouth and Norwich line, his use of the telegraph made possible the economy of a single track line, with reliable and immediate communication between stations.  At first telegraph lines were used exclusively for railways, but then the advantages of a public communication service were seen and the demand for telegraphs grew.  George Bidder was active in promoting the formation of the Electric Telegraph Company in 1846 to finance this development, and he played a large part in the day-to-day running of the company, and in the eventual development of  transatlantic cables.

He is said to have been responsible for recommending the employment of women as telegraph operators, the first “office” job for women.  Eventually, in 1869, the Post Office took over the telegraph service and these women became the first female Civil Servants !  The Home Civil Service long led in providing equal opportunities for both sexes, for which Bidder must take some of the credit.


Stephenson and Bidder were also active abroad, often represented by Bidder himself.  From the 1840’s they made several journeys to Norway, where they constructed the first railway in Norway from Christiana (now Oslo) to Eidsvold, which opened in 1854. Bidder was also active as engineer-in-chief of the Royal Danish Railway, which opened in 1855, and at the same time he introduced gas lighting to Denmark, through an English company set up by himself and two other Englishmen.  He continued to have an interest in the Danish Gas Company, and was in fact Chairman in 1870; the company continued to run until 1963.

In the 1850’s Stephenson and Bidder also visited Switzerland, to devise plans for the Swiss Federal railway system.

Bidder was also consultant engineer to various Indian railways from the 1860’s.  He never went there himself, but one of his brother John’s sons, Edwin, who became a Civil Engineer and died in Lahore in 1872, may well have been directed there by his uncle.

A measure of his reputation abroad is that he met at least four foreign monarchs – the King of Norway on the occasion of the opening of  the Norwegian railway, King Leopold of the Belgians who was advised by him and Stephenson on railway matters, the King of Denmark when he was visiting the Danish railway, and the French Emperor who entertained him with a delegation from the Institution of Civil Engineers in 1869.


Throughout his professional career Bidder was involved with work on docks, especially London Docks where major new work was needed – and where he cut his teeth on actual work sites (as opposed to surveys and planning) .  The Victoria Docks, built in the 1850’s and largely due to his ideas, were a major contribution.  They included a graving dock which was the largest then in existence, with the largest lock gates (of original design) and hydraulic lifts for the ships (another innovation).  When planning the railways which became the Great Eastern he was responsible for choosing Lowestoft as the terminus and designing its harbour.

He also made a major contribution to the plans for the long-awaited main drainage of London, not as engineer but as consultant and adviser to the various political committees involved and then to the Metropolitan Board of Works which eventually took action.

Water was something he felt strongly about.  His Presidential Address to the Institution of Civil Engineers deals with the importance of hydraulics, drainage and tidal effects to Civil Engineers and of maritime engineering to the nation; his Presidential Address to the Devonshire Association, of which he was President in 1869, is on the subject of Rivers.


Bidder joined the Institution of Civil Engineers in 1825, at the very start of his career, and played an active part in its meetings and debates.  He served on its Council, became a vice-president, and succeeded Joseph Locke as President in 1860-1.  As we have seen, his range of interests was very wide, and he was always ready to try out novel ideas and put them to practical use.  Noteworthy examples are the application of the electric telegraph, the use of steam power for fishing trawlers, the design of swing bridges, and the use of hydraulic power to raise ships in the Victoria Docks.

He was a working engineer, but good at delegating once the original surveying, costing and planning had been done.  His appreciation of the practical side is shown in his publication of “Bidder’s Tables”, a calculating device to enable those without his arithmetical skill to work out the volume of earth to be moved in a cutting or embankment.

Bidder was a contemporary of I.K. Brunel.  The two men respected each other but often found themselves on opposite sides in disputes between railway companies.  Their most important difference was over the adoption of a standard gauge for all British railways.  Brunel’s broad gauge lines in the west were incompatible with the narrower gauge used elsewhere, and Bidder, a stalwart defender of the principle of a single gauge,  won the day.

Brunel designed beautiful structures, but his projects were often delayed by overrunning budget, whereas Bidder’s projects, meticulously costed, were always completed on time and within budget.  Brunel’s Clifton suspension bridge could not be completed in his lifetime because of lack of money, and was only finished later by a group of men, including George Bidder, who raised money for the purpose after his death.


Bidder was a man in the right place at the right time – his calculating ability and memory for figures were very useful in his chosen profession, and he was able to work very hard at a number of projects simultaneously.  His ability also attracted the attention of  influential figures who were useful contacts – such as Isaac Solly, Director of the Royal Exchange Assurance Company, Chairman of the London Dock Company and of the London & Birmingham Railway Company, who indirectly employed Bidder in all three.

When he started earning money, his first thought was to help his family with money or introductions to careers, but when he was able to invest money he did so in a variety of projects.  Investment for him meant taking an active interest and a share in the management of a project.  A good example of this is the Electric Telegraph Company, but it is also typical that when he was spending more time in Dartmouth he became involved with the Torbay and Dart Paint Company – which made anti fouling paint for iron from local haematite – and the Buckland Slate quarry.  He also had an active interest in coal mines, a Welsh slate quarry, and Indian trading ventures.

He also invested in land, especially building land, not only in  England but in Norway where he owned property, and especially bought where he could see that the new railways he was building would bring a need for housing.


As George Bidder moved up in the world and began to have money to spend, he did not forget his relations in Moretonhampstead.  He enabled his parents to move into Exeter, while his brother John carried on as a builder in Moreton.  His support not only helped with the education of his younger brothers, but launched them into careers. Bartholomew obtained a post at the Royal Exchange Assurance Company in London (where George had worked briefly) and rose to be their Actuary.  It is said that Bart too had a phenomenal memory for numbers, and that when the company’s records were destroyed by fire he was able to restore them from memory.  Samuel followed George into railway engineering, working on the London & Birmingham Railway and others, finally becoming the General Manager of the Grand Trunk Railway in Canada during its construction.

Two of John’s sons, George and Edwin, also became Civil Engineers and their death’s are recorded in St Andrews Church in Moretonhampstead.  George’s letters show that he continued to visit Moreton and Exeter, and owned farm land in Moreton.

In 1835, George married Georgina Harbey, whom he had met in London.  They lived for a time in Walworth, but in 1846 they bought Mitcham Hall in Surrey where most of their children were born.  They later bought the nearby Ravensbury estate, and on it built Ravensbury Park House to which the family moved in 1864.

Meanwhile in 1860  they bought a house and land at Paradise Point, just north of Warfleet Creek in Dartmouth.  The name of this house was changed to Ravensbury, which Mrs Bidder preferred, and  they spent a gradually increasing amount of time there.

Throughout their married life, in spite of the enormous pressure of business, George Bidder was an assiduous correspondent, writing regularly to his wife and children when he was away from home. These letters are now an important source of information about his affairs.

George and Georgina had 8 surviving children and 28 grandchildren.  Their eldest son, also George Parker Bidder, read mathematics at Cambridge with distinction, then became a QC, specialising in Parliamentary work.  His son, the third George Parker Bidder, was a distinguished zoologist, becoming President (and a notable benefactor) of the Marine Biological Association, and President of the Devonshire Association. The whole family tree contains a galaxy of engineers and lawyers.


Bidder made trips, combining business and pleasure, in Robert Stephenson’s yacht, and in 1853 he acquired his own yacht the Mayfly (a yacht, for a wealthy Victorian, being the equivalent of today’s executive jet !).  It may have been this which led him to buy property in Dartmouth.

As he began to spend more time in Dartmouth he took a larger part in local affairs. In 1868 he was invited to stand for the Town Council in the hope that he would become Mayor (with the support of both parties), but he declined this office because he was still spending too much time in London.  However he topped the poll for the Council on which he served in 1868-71, and contributed advice to the work then being planned to drain the centre of the town, and to plans to improve the water supply.  He also contributed, with his neighbours, to the new road and bridge across Warfleet Creek.

One of his friends while he lived in Dartmouth was William Froude, who borrowed his steam-launch as a tow for his early experiments in ship design, comparing two model hulls by towing them either side of the launch from the ends of a boom to keep them clear of the wash.  This work was probably carried out in the River Dart.  Bidder was also a founder member of the Dart Yacht Club and was instrumental in enabling it to acquire the Royal warrant.

Another Dartmouth venture was his interest in the development of steam trawlers.  He must often have watched sailing vessels struggling with the entrance to the Dart, and had plenty of experience of commercial steamships, so he felt the use of steam would benefit the local fishing industry.  In partnership with a Dartmouth trawler owner, Samuel Lake, he commissioned several steam trawlers for experiment, providing steam power for hauling nets and raising anchors  as well as for propulsion.  He succeeded in showing that the steam engine did not scare the fish away, but there were other problems and the venture was not financially viable – it was an idea ahead of its time.

In 1877 Bidder transferred Ravensbury Park House in Surrey to his eldest son and bought Stoke House at Stoke Fleming, which he planned to enlarge.  Before this work was completed, in 1878, he died, but his funeral cortege went through the grounds of Stoke House on its way to Stoke Fleming Churchyard, where he was buried.   He left the house to his widow and unmarried daughters, and his daughter Bertha lived there until 1937.


How did he do it ?  We have his own account, in a lecture given to the Institution of Civil Engineers in 1856,  and reported comments to others .  Having learnt to calculate before he learnt to write, he saw numbers as shapes in his head, and he had a tremendous ability to remember them.  To multiply two 3-digit numbers, he started from the left, multiplying first the hundreds together, and adding each successive product to the total so as to hold as few intermediate sums in his head during the calculation as possible.  When multiplying very large numbers, he felt that his capacity was limited by the number of intermediate totals that he could “store” before completing the sum; the multiplications themselves were very fast.   He also carried in his head the key results of earlier calculations – such as the number of inches in a mile or seconds in a year – and the squares and cubes of 2-digit numbers, and as his experience developed he devised many short cuts, and learnt to use successive approximations to reach the answer.

With this technique, and the practice of deducing new rules as he went along, plus obvious intelligence in reducing an elaborately worded problem to its numerical essentials, he was able to amaze his interrogators.  Looking at the questions he was asked, many of them are difficult only because of the size of the numbers involved (astronomy was very popular!) but some involve logic rather than calculation, and he obviously took these in his stride. He himself believed that it should be possible to teach children his methods to improve their mental arithmetic, but without his capacity for remembering numbers it would not have helped.  His ability lasted into old age, and in his professional career there are many examples of his ability to remember large volumes of data.

Further reading (copies of the articles are available in the library)

E.F. Clark, “George Parker Bidder, The Calculating Boy”, KSL Publications, 1983,  ISBN 0-9508543-0-1.

A Short Account of George Bidder, the celebrated Mental Calculator; with a variety of the most Difficult Questions proposed to him …., KSL Publications, 1995,  ISBN 0-9508543-1-X

W. Pengelly, Trans. Devon. Assoc. 1886, 18, 309-315.

Obituary memoir, Min. Proc. ICE. 1879, 57, 294-309.

Presidential Address, G.P.Bidder, Min. Proc. ICE. 1860, 19, 214 et seq.

Presidential Address, G.P. Bidder, Trans. Devon. Assoc.  1869, 3, 17 et seq.

G.P. Bidder, On Mental Calculation, Min. Proc. ICE. 1856, 15, 251 et seq.

Devon Notes & Queries 1902, 2, 1-2.