Charles Wheatstone

Sir Charles Wheatstone (6 February 1802 - 19 October 1875) was an English physicist and inventor who gave the first published explanation of stereoscopic depth perception and devised the first stereoscope, the instrument that presents a separate picture to each eye so that a pair of flat drawings or photographs is seen in relief. He read his paper "Contributions to the Physiology of Vision" to the Royal Society on 21 June 1838, and it appeared the same year in the Philosophical Transactions. The Royal Society awarded him a Royal Medal for the paper in 1840.

Wheatstone was Professor of Experimental Philosophy at King's College London from 1834 until his death. Outside optics he is remembered for the electric telegraph he patented with William Fothergill Cooke in 1837, for the concertina, and for popularising the resistance-measuring circuit now called the Wheatstone bridge. He was knighted in 1868.

The principle Wheatstone demonstrated, that the brain builds a sense of depth from the small differences between the two retinal images, is the basis of every stereoscopic display, including the head-mounted displays used for virtual reality. A 2014 review in Frontiers in Neuroscience credits him with first defining stereopsis "as the perception of depth that results from slight differences in the visual projection of the world onto the two retinas". Museum writing on the history of virtual reality, such as the New Orleans Museum of Art's account of stereoscopes as "nineteenth-century virtual reality devices", starts the story with his instrument.

Reviewed 20 September 2026. Biographical dates, the 1838 and 1852 Royal Society papers and their quotations, the Talbot and Brewster history, the honours table and every cited source. About review dates.

Early life and education

Wheatstone was born on 6 February 1802 in Barnwood, near Gloucester, the second of four children of William Wheatstone, a shoemaker, and his wife Beatta. The family moved to London in 1806, where he attended school. At fourteen he was apprenticed to an uncle who made musical instruments. He disliked the trade but took an interest in the physics of sound, in what distinguishes notes of the same pitch but different timbre, and in how sound travels through rods and stretched wires. When the uncle died in 1823, Wheatstone and his younger brother William took over the business, and the same year he published his first paper on sound in Thomson's Annals of Philosophy.

Career

Musical instruments and acoustics

The instrument business gave Wheatstone his first inventions. He devised several instruments, among them the concertina, which he patented in 1844. His acoustic research in the 1820s and early 1830s, on the transmission of sound through solid conductors and the vibration of air columns in tubes, was published and presented at the Royal Institution before he held any academic post.

King's College London

In 1834 Wheatstone was appointed Professor of Experimental Philosophy at King's College London, a chair he kept until his death in 1875. One of his first experiments there used a revolving mirror to measure the speed of electricity through a conductor; on his suggestion the same rotating-mirror method was later applied to measuring the speed of light. He was elected a Fellow of the Royal Society in 1836. His colleague at King's, the physiologist Herbert Mayo, gave the first printed notice of Wheatstone's unpublished binocular-vision work in the 1833 edition of his Outlines of Human Physiology.

Electric telegraph

With William Fothergill Cooke, Wheatstone patented an electric telegraph in May 1837. The partners patented an ABC (dial) telegraph in 1840 and, in 1845, a single-needle instrument; John Lewis Ricardo bought the patent and founded the Electric Telegraph Company. Wheatstone patented an automatic telegraph in 1858, in which a message was first punched into paper tape and then sent and received at high speed, and he later worked on submarine telegraphy. In 1867 he described to the Royal Society a method of making dynamos self-exciting, at the same meeting at which Werner Siemens reported a similar result.

Other work

In 1843 Wheatstone brought to notice the resistance-measuring bridge circuit that has carried his name ever since, although it had been invented by the mathematician Samuel Hunter Christie. He also invented the Playfair cipher, a substitution cipher that encodes pairs of letters, and a system of electromagnetic clocks driven from a single circuit.

Binocular vision and the stereoscope

Experiments before 1838

Wheatstone's binocular experiments began well before their publication. According to the vision historian Nicholas Wade, both mirror and prism stereoscopes "were constructed for him as early as 1832" by Murray and Heath, optical instrument makers in London. Wheatstone himself wrote in 1852 that the investigations had been announced, still unpublished, in Mayo's 1833 textbook, "five years before the publication of the memoir".

The 1838 paper

Wheatstone presented the reflecting stereoscope and his account of binocular vision to the Royal Society on 21 June 1838, and again later that year at the British Association for the Advancement of Science meeting in Newcastle. The paper, "Contributions to the Physiology of Vision. Part the First. On some remarkable, and hitherto unobserved, Phenomena of Binocular Vision", was printed in volume 128 of the Philosophical Transactions of the Royal Society, pages 371 to 394.

Its starting observation is that a painting and the solid object it depicts project different things onto the two eyes: "in the case of the painting two similar pictures are projected on the retinæ, in the case of the solid object the pictures are dissimilar". Wheatstone argued that the mind perceives relief by combining these two dissimilar pictures, and drew the consequence that no flat picture can reproduce the appearance of a near solid object, however skilfully it is painted, because it delivers the same image to both eyes. He noted that this difference disappears for distant objects, viewed with the optic axes parallel, where an object in relief and its perspective projection look the same. Leonardo da Vinci had touched on the same observation without pursuing it, and Wheatstone cited him.

To test the idea he needed a way to show each eye its own drawing. The instrument he described has "two plane mirrors, about four inches square, inserted in frames, and so adjusted that their backs form an angle of 90° with each other"; the observer looks into the pair of mirrors from the vertex, and two panels holding the left and right drawings slide toward or away from the viewer until the reflected images coincide. He named it in the same paper: "I therefore propose that it be called a stereoscope, to indicate its property of representing solid figures." Because photography did not yet exist, the paper's demonstrations were pairs of line drawings, and Wheatstone discussed the instrument's possible uses in art. He also reported that he had trained himself to fuse stereo pairs without any viewing aid.

The Royal Society awarded Wheatstone a Royal Medal in 1840 for the paper. Wade describes the stereoscope and the stroboscopic-motion devices of the same decade as "philosophical toys" that served both as experimental instruments and popular amusements, and observes that the stereoscope "rendered the normal conditions for seeing depth from disparity experimentally tractable".

Photography

William Henry Fox Talbot announced his photographic process to the Royal Society in 1839, and Wheatstone asked him almost at once for stereoscopic pairs. In his 1852 lecture Wheatstone recalled that "at the beginning of 1839, about six months after the appearance of my memoir in the Philosophical Transactions, ... the photographic art became known, and soon after, at my request, Mr. Talbot, the inventor, and Mr. Collen ... obligingly prepared for me stereoscopic Talbotypes". The Royal Society's archivist dates Talbot's first pairs, made at Lacock Abbey, to 1840; the Stereoscopic Society describes them as the first photographic 3D images ever made and notes that the originals are lost. Wheatstone also approached Antoine Claudet, a London daguerreotypist, in 1840, and later credited Fizeau and Claudet with the first stereoscopic daguerreotypes. Wade notes that the popularity of stereoscopes "increased enormously after 1840, when combined with photography".

The 1852 lecture and the pseudoscope

Wheatstone returned to the subject in the Bakerian Lecture read to the Royal Society on 15 January 1852 and printed as Part the Second of the same title in volume 142 of the Philosophical Transactions. It describes an adjustable mirror stereoscope, a prism stereoscope, and a new instrument that swaps the disparities between the eyes so that convex objects appear hollow and near things appear far. "As this instrument conveys to the mind false perceptions of all external objects," he wrote, "I have called it the Pseudoscope." The lecture acknowledged that "several ingenious arrangements have also been proposed by Sir David Brewster and Prof. Dove" since 1838.

Dispute with Brewster

The Scottish physicist David Brewster at first welcomed the 1838 paper, but by 1844 the two men were at odds. Brewster announced his own lenticular stereoscope, which fuses the images with paired half-lenses instead of mirrors, in 1849; the first was made by George Lowdon in Dundee. Brewster turned to the Paris optician Jules Duboscq to supply the instrument, and Duboscq's stereoscopes were shown at the Great Exhibition in London in 1851, where Queen Victoria saw stereoscopic images for the first time. The compact lens viewer, not Wheatstone's mirror box, became the mass-market form: the New Orleans Museum of Art puts sales at more than half a million on both sides of the Atlantic by 1856, and the London Stereoscopic Company was founded in 1854 to supply views for it.

The quarrel was about credit as much as instruments. Brewster claimed that Wheatstone had taken no interest in using photographs with the stereoscope; Wheatstone answered in the 1852 lecture that he had commissioned photographs as soon as Talbot revealed his process in 1839. In his 1856 book The Stereoscope: Its History, Theory, and Construction, Brewster asserted that a Scottish teacher, James Elliot, had invented an "ocular stereoscope" in 1834; Elliot later retracted the claim made on his behalf. In the correspondence about the dispute printed in The Times, Wheatstone wrote that he had "hitherto avoided entangling myself in the meshes of controversy with so disputatious an antagonist as Sir David Brewster". Wade traces the split partly to theory: Wheatstone held that binocular depth was a mental combination of the two images, while Brewster looked for an explanation in the retinas themselves.

Honours

Year	Honour
1836	Fellow of the Royal Society
1840	Royal Medal of the Royal Society, for "Contributions to the Physiology of Vision"
1843	Royal Medal of the Royal Society, for a paper on the constants of a voltaic circuit
1855	Chevalier of the Legion of Honour
1862	Honorary DCL, University of Oxford
1864	Honorary LLD, University of Cambridge
1868	Knighthood
1868	Copley Medal of the Royal Society, "for his researches in acoustics, optics, electricity, and magnetism"
1873	Foreign associate of the Academie des Sciences, Paris
1875	Honorary member of the Institution of Civil Engineers

Death

Wheatstone died of bronchitis on 19 October 1875 at the Hotel du Louvre in Paris, while there on business, aged 73. He was buried on 27 October at Kensal Green Cemetery in London. He bequeathed his library, instruments and papers to King's College London, whose archives hold what the college describes as the largest collection of stereoscopic pairs for the Wheatstone reflecting stereoscope in the world. The Science Museum Group holds a reflecting stereoscope "originally used by Sir Charles Wheatstone", a mahogany, brass and glass instrument made in London around 1850 that measures 355 mm by 910 mm by 265 mm.

Legacy in VR and AR

What virtual reality inherits from Wheatstone is a principle rather than a device: a pair of two-dimensional images with small horizontal differences, one delivered to each eye, is enough for the brain to construct depth. The 2014 Frontiers in Neuroscience review by Rojas and colleagues describes this binocular disparity as the phenomenon Wheatstone defined in 1838, defines a stereoscopic display as one that presents two offset images separately to the left and right eyes, and lists stereoscopes first among the approaches to 3D display that followed. Head-mounted displays for virtual reality are stereoscopic displays in that sense. Wade's account of the 1825-1835 London experiments places Wheatstone as "the catalyst involved in all these developments", the instruments that made both apparent motion and disparity-based depth controllable in the laboratory.

The New Orleans Museum of Art traces the line from his mirror box to today's headsets through the hand-held viewers of Brewster and of Oliver Wendell Holmes, whose 1859 design dominated the market from the 1880s into the 1940s, and the View-Master of 1939; it presents the stereoscope and virtual reality as answers to the same wish for visual escapism and armchair travel.

Wade also notes that the optical manipulation of disparities was achieved a second way in the 1850s with Wheatstone's pseudoscope, which reversed them.

See also

• Stereoscope
• Stereoscopy
• Stereopsis
• Binocular disparity
• History of virtual reality