Robert Thomson (1822 - 1872)
Robert Thomson invented the pneumatic tyre in December 1845 and his memory is kept fresh annually by a vintage car rally held in June on the Market Square in the town centre directly opposite the site of the house where he was born.
Robert was the eleventh of twelve children of a local woolen mill owner. His family wished him to study for the ministry but Robert refused, one reason being his inability to master Latin. He left school at the age of 14 and went to live with an uncle in Charleston, USA, where he was apprenticed to a merchant. Two years later he returned home and taught himself chemistry, electricity and astronomy with the help of a local weaver.
Robert's father gave him a workshop and by the time he was 17 years old he had rebuilt his mother's tangle so that wet linen could be passed through the rollers in either direction, a ribbon saw, and had completed the first working model of his elliptic rotary steam engine.
He patented the pneumatic tyre in France in 1846 and in the USA in 1847. His tyre consisted of a hollow belt of India-rubber inflated with air so that the wheels presented "a cushion to the ground, rail or track on which they run". This elastic belt of rubberized canvas was enclosed within an outer casing of leather bolted to the wheel.
Thomson's "Aerial Wheels" were demonstrated in London's Regent Park in March 1847 and were fitted to several horse-drawn carriages. One set ran for 1200 miles without sign of deterioration. However, despite satisfactory testing the tyre developed no further at this time because the North British Rubber Company was unable to supply the strong thin rubber necessary for the inner tubes. For many years Thomson was frustrated by this lack of thin rubber and he turned to the development of his solid rubber tyres. It was not until 43 years later that the pneumatic tyre returned when it was developed as a bicycle tyre by John Boyd Dunlop. Dunlop was granted a patent in 1888 but two years later was officially informed that it was invalid as Thomson's patent had preceded it.
At the Great Exhibition in 1851 Thomson demonstrated his self-filling fountain pen and an invalid chair with solid rubber tyres. The following year he accepted a post in Java, where he designed new machinery for the production of sugar, thus greatly increasing profitability. During this time he invented the first portable steam crane but did not patent it. In 1867 he patented solid India-rubber tyres for his road steamers.
The Scotsman described this application of vulcanised India-rubber "the greatest step which had ever been made in the use of steam on common roads". The resilience of the stout rubber tyres allowed his lightweight five ton steam engine to run on hard or soft, wet or dry surfaces, over obstacles, uphill or downhill. In addition, the thick rubber tyres did not damage the roads as did the iron wheels of heavy traction engines. Thomson's first road steamers, manufactured by Tenants of Leith, were fitted with three wheels, the small single wheel at the front being directly below the steering wheel. The tyres, which were 125 mm (5") thick, were corrugated and adhered to the wheel by friction.
Thomson's road steamers, often drawing four fully loaded coal wagons totaling 40 tons up and down steep gradients, excited great interest. Soon the first omnibus was in service between Edinburgh and Leith. Engines were exported to Java, India and Brazil, and by 1870 were being manufactured in the USA. Demonstrations of the engine's ability to plough effortlessly with two double-furrow ploughs had a major impact on farming practices and led to the eventual demise of the working farm horse.
In 1873 R. W. Thomson, died at his home in Moray Place, Edinburgh.