James Sadler

The local innovator who became an international celebrity and hero of science

“Early Monday morning the 4th instant, Mr. Sadler of this city, has experimented with his ball of fire, raised by the thin air.

The process of filling the Globe began three hours, and about half past five that everything was complete, and every part of the unit all set, Mr. Sadler, with firmness and intrepidity, got in the atmosphere, and the time is calm and serene, he rose from the earth in a vertical direction to a height of 3,600 feet. In its high position he perceived no problem, and, being freed from all earthly things, he looked a distant view of the most charming.

After floating for about half an hour, the machine fell, and finally came upon a small hill between Islip and Wood Eaton, about six miles from this city. ”

Oxford Journal, October 4, 1784

Oxford Hero

James Sadler is this country’s true pioneer of flight. He became the first Englishman to fly; an accomplishment rendered even more remarkable by achieving this landmark feat in a balloon he designed, built and piloted himself. Furthermore he attained this historic first here in Oxford.

Indeed, Sadler is the ultimate Oxford hero – and uniquely his achievements bring together Town and Gown. Unlike many of the greats associated with Oxford, who have only resided here fleetingly during their time at the University, Sadler was Oxford born and bred. He was christened (in 1753) in the same church where he is buried just off the city’s High Street. He worked in an Oxford pastry shop before becoming a laboratory assistant in the Old Ashmolean’s basement. And it was Oxford where he achieved greatness.

Sadler attempted to launch his balloon secretly from Christ Church Meadows in a pre-dawn flight in October 1784. Fortunately for posterity, witnesses were present and history was recorded, referred to as a ‘Fire Balloon raised by means of rarefied air’. A month later, he returned to his launch site, this time advertising his intention in advance by displaying the balloon in Oxford’s Town Hall and charging townspeople a shilling to inspect it. In November the same year he took off in front of a crowd of tens of thousands and drifted towards Thame. On his return, he was paraded around the city by jubilant crowds.

Oxford was the scene of Sadler’s first triumph and the birthplace of English flight.

Pioneer of Flight

Always experimenting, within a month of the historic first ascent Sadler had jettisoned hot air balloons as redundant technology. His second launch from Magdalen College was in a self-built gas balloon, fuelled by primitive hydrogen he had created at a time when the element was so new that the term ‘hydrogen’ had yet to be coined.

Unlike the Montgolfiers, who mistakenly concluded that smoke was required for airborne propulsion, Sadler took off from Oxford realising that the properties of air are fundamentally altered by heat. He covered his self-designed stove with a lid, showing that smoke was irrelevant to the lifting process.

Perhaps the flying autodidact’s greatest achievement was possessing the necessary scientific wisdom to survive, in an era when most of his fellow pioneering aeronauts perished. Pilâtre de Rozier may have been the first person in human history to fly – ascending in the Montgolfier brothers’ famous balloon in France in late 1783 – yet a few months later he had also become the first person to die in an aviation accident.

Sadler became an undisputed polymath – unprecedented for someone without formal education yet ironically growing-up under the long shadows cast by the Dreaming Spires. Fittingly, his epitaph was uttered during his lifetime, when the scientist Sir John Coxe Hippisley was moved to observe in 1812: ‘There is not a better chemist or mechanic in the universe, yet he can hardly speak a word of grammar.’

Scientific Innovator

Having made seven ascents between October 1784 and September 1785, culminating in a terrifying crash in his final flight, he temporarily retired from aeronautics. Next Sadler worked for the Royal Navy. Noting through empirical experiments he designed and conducted himself that nearly half of all British rifles and cannons missed their intended target (the French!) by several feet, he set about designing vastly more efficient munitions. Shipboard cannons had a disturbing tendency to blow up on deck, often posing more danger to their operators than to their enemies. Sadler applied himself to rectifying the accuracy and efficiency of British guns, modifying the Royal Navy’s firepower to such an extent that he directly affected the outcome of the war with Napoleon. Admiral Lord Nelson certainly thought so, and expressed such an opinion publicly: ‘I would take on board the Victory as many guns as Mr Sadler could send alongside.’ Sadler patented a 32-pounder gun that was far more accurate than its predecessor and only required three men to operate instead of twelve. He conducted research into copper sheathing of ships, distillation of sea water and seasoning of timber, then invented air pumps, signal lights and several models of steam engine. He even started a mineral water company, with a semi-automated bottling plant run by a self-designed steam engine. Ingeniously his bottles carried a trademark balloon motif!

National Celebrity

With the exception of monarchs, hardly anyone would have received mass recognition by their face in the late eighteenth century. Yet engravings of Sadler were big-selling, mass-produced items. Even rarer for a celebrity of the age were his humble origins.

An uneducated pastry cook, he consorted with nobility, admirals and Cabinet ministers at a time when social mobility was unknown; he was even granted an audience with the Queen. Adored by the British public for fully fifty years, he is perhaps best summed up by the Daily Chronicle: ‘Sadler is known from the humble cabbage seller to the mightiest of lords.’

Part of Sadler’s appeal as a self-taught chemist, inventor and engineer was undoubtedly enhanced by his image as an old-fashioned, derring-do daredevil. Frequently taking off in force 7 gales, crashing into hills and plopping into seas, Sadler regularly survived basket-splintering crashes in extraordinary acts of courage. Twice he had to be rescued from the freezing waters of open seas when fortuitously spotted by passing ships.

Fanned by Sadler’s achievements, Balloonomania duly gripped a nation increasingly hysterical about human flight. For several decades, the country went balloon crazy – if you wanted to sell anything in this period of British history then adding a balloon motif to your product was mandatory: from snuff boxes to ladies’ under garments and bidets.

Yet Sadler maintained an enquiring scientific mind throughout such celebrity status. Measuring instruments and apparatus accompanied him on all ascents. He was the first to measure “sky air” and decipher its components – an unknown at a time when some warned that he risked crashing into heaven! Wherever he went, his balloon launches would regularly attract an audience in excess of 30,000 people. Contemporary newspaper reports confirm that entire towns and cities would close every shop, school and factory for the day in Sadler’s honour.

It is the pleasure of HRH the Prince Regent to declare a Grand Jubilee in celebration of the recent victory over Napoleon culminating in the present Glorious Peace and in honor of the Centennial of Hanoverian rule.

Amazed crowds witnessed the ascent of Mr. James Sadler in his balloon opened the festivities. Sadler dropped favors and programs to the thrilled crowd below.


James Sadler (1753-1828), balloonist, engineer and chemist, of Oxford
1753 born in Oxford and baptized there on 27 February 1753, elder son of James Sadler (1718–1791), cook and confectioner and his wife, Elizabeth (1718–1802).
He and his brother Thomas (1756–1829) worked in their father’s business.
Married Mary. Four children born before 1785, including John, their eldest son.
1784 Sadler released a 36 foot hydrogen balloon, probably from the St Clement’s residence of John Sibthorp, on 9 February. Constructed a 170 foot hot-air balloon in which he made the first ascent by an English aeronaut on 4 October; the balloon rose to 3600 feet and landed 6 miles away after a half-hour flight.
1785 Further balloon ascents were made; Sadler then changed to other experiments.
c.1785 was one of the first to use coal gas as an illuminant.
By 1786 was experimenting with driving a wheeled-carriage using a steam engine.
From about 1788 to 1790 Sadler was technical operator in the chemical laboratory at Oxford University.
1789-90 Gave public performances “of philosophical fire-works” in Oxford Town Hall.
Sadler was closely involved with Thomas Beddoes, reader at Oxford University; Beddoes and his friend William Reynolds encouraged Sadler to experiment further with his steam engine. This engine did not condense steam in the cylinder, which laid it open to claims of infringement by Boulton and Watt. It worked at a pressure of 19 pounds per square inch and was self-contained and direct acting.
1791 Boulton and Watt threatened Sadler over his supposed infringement of Watt’s patent
1791 Patent (no. 1812 of June 1791) for a
quite different type of steam engine, a rotatory engine.

His first wife probably died in or after 1791
1792-99 Several Sadler engines were built and erected at Coalbrookdale, and in London.
1793 Beddoes left Oxford. He sent Sadler to London to set up his Pneumatic Institute but Bristol was soon chosen instead.
1795 Appointed barracks master at Portsmouth.
1796 Appointed chemist to the board of naval works in London.
1796 Married a second time to Martha Hancock in Bristol; they had a son (William) Windham Sadler (1796–1824) in October 1796.
Sadler also established a mineral water factory near Golden Square in London.
1798 Patent for a double-cylinder engine
1799 Erected the Admiralty’s first steam engine at Portsmouth. Sadler researched copper sheathing of ships (with Humphrey Davy), distillation of sea water, seasoning of timber, and gunpowder combustion, and constructed air-pumps, signal lights, and apparatus for producing oxygen. Outside his naval work Sadler tried to improve alum making. He was elected a life subscriber to the Royal Institution in 1799.
At some point was involved with his friend, Revd Dr Henry Peter Stacy, in gun-boring experiments in London.
1810 Resumed aeronautics professionally, using his balloon trademark to sell soda water.
1815 Sadler had achieved his forty-seventh ascent.
From 1824 Sadler lived in the London Charterhouse from the second quarter of 1824 His son Windham was killed in a ballooning accident in September.
1827 Moved back to Oxford to live with his family.
1828 Died in Oxford on 26 March, in George Lane.