As technicians, the virtuosos produced marvelous mechanical objects, pub-lished marvelous technical knowledge, and performed marvelous bodily exertions. The leaps of acrobatism in the second half of the eighteenth and first half of the nineteenth centuries testified to the increasing value the French placed on technical skill as expressed in bodily exercise. The vaulting popularity of acrobatics brought into the spotlight skills cultivated by the virtuosos, skills such as agility, flexibility, mobility, balance, stamina, and fluency of movement, which enabled them to execute feats unprecedented in their respective arts. The virtuosos thus pointed the way to a new transcendence, not to a heavenly eternity but to an earthly future of ever-expanding possibility in which there seemed to be no limit to what the human body, including the brain, could be trained to do.
The leaps of acrobatics into a variety of more highly regarded art forms and into cultural prominence in its own right had a lot to do with the success of the Paris fairs in the eighteenth century. The success of the fairs as spaces for public spectacles led to the development of larger and more permanent spaces for public spectacles, the Grands Boulevards and the Palais-Royal. The success of the fair theaters led to the founding of boulevard theaters and the defeat of the privileged theaters during the Revolution. There ensued an explosive growth of popular theater and its arts du spectacle—acrobatics, equestrianism, puppetry, pantomime, etc.—as arts in their own right, as vehicles for the presentation of dramas, and as elements to be incorporated into elite theater. Elite culture’s adoption of the arts du spectacle, like elite culture’s adoption of the mechanical arts, seems to support Peter Burke’s hypothesis of a rediscovery of popular culture by the elite in the second half of the eighteenth century, for it followed the increasing attendance of popular theater at the fairs and on the boulevards by the elite. Acrobatics in particular gained phenomenal favor among the elite and among the masses and invaded not only theater but also dance, tennis, music, mechanics, detection, chess.…
At the beginning of the eighteenth century, acrobats had low status among performers, a group that as a whole had low status in society at large. But acrobatics had been a mainstay of the fair theaters since well before that time. And a mainstay of fair theater acrobatics was funambulism or rope-dancing, gymnastics performed on a rope, whether a tightrope or a slack rope, whether a rope with both ends secured above the ground or a rope with one end secured at ground level. Funambulists would imitate the stagger of a drunkard, dance with chains attached to their feet, or simply balance while playing a violin between their legs. Performances of aerial and terrestrial acrobatics became increasingly frequent when, beginning in the 1760s, the impresarios of the fair theaters began to establish permanent theaters on the Boulevard du Temple. The first such impresario to set up on the Boulevard, Jean-Baptiste Nicolet, like his followers, eventually expanded into spoken and musical drama, but his players were originally an acrobatics troupe. One of Nicolet’s star rope-dancers was Jean-Baptiste Lalanne, the father of Mme Saqui. Nicolet’s players attracted the attention of King Louis XV, who invited them repeatedly to perform at court. Louis XV’s grandson the comte d’Artois, who later became king himself as Charles X, solicited from Nicolet’s funambulists a series of equilibristic lessons, which however did not keep him from falling off his throne in the Revolution of 1830. Nor did the revolutionaries disdain demonstrations of bodily skill, for a fête staged by the Directory in 1799 included a gymnastics competition. Napoleon, we know, became the admiring patron of Mme Saqui, one of whose specialties was tightrope-walking over the Seine in the middle of Paris. During the Empire, Mme Saqui acquired a celebrity surpassing that of any other rope-dancer and equaling that of any contemporary actor or singer. Milliners sold hats and collars à la Saqui, and confectioners sold boxes of candy bearing her portrait. At the beginning of the Restoration she bought a theater on the Boulevard du Temple and renamed it the Spectacle-Acrobate.
The boulevard theaters of Nicolet and his imitators, we have learned, gradually encroached on the exclusive right of the privileged theaters to perform spoken or musical dramas. Nicolet’s theater had as its motto “de plus fort en plus fort,” which translates as “stronger and stronger” or “louder and louder”—the crescendo of the virtuoso. Many of the boulevard pieces, acrobatic, balletic, operatic, pantomimic, and zoologic alike, used music from the comic operas of Philidor, music distinguished by its technical perfection. The monarchy helped to erode its own system of theatrical privilege when King Louis XV invited Nicolet’s players to the royal court and then allowed them to change their name from the Grands Dan-seurs de Corde (Grand Rope-Dancers) to the Grands Danseurs du Roi (Grand Dancers of the King). Soon acrobatics was everywhere in theater. Alexandre Placide, another of Nicolet’s star funambulists, moved to the United States, where he became a successful producer of French boulevard pieces and never quit performing on the rope. Among prominent Paris theaters of the early nineteenth century, the Funambules featured acrobatic pantomime; the Porte-Saint-Martin, known for five years as the Jeux-Gymniques, acrobatic ballet; the Cirque-Olympique, acrobatics on horseback; the Gymnase, acrobatic vaudeville.
The invasion of dance by acrobatics was readily apparent to contemporaries. In 1804 the German playwright August von Kotzebue was in Paris, where he wrote of the dancer Louis Duport: “He possesses among other things the absolutely extraordinary strength and agility to pirouette forty or fifty times on one leg. However, since he knows that every time he does it he will be applauded as loudly as if the entire world had assembled for the purpose of clapping, he takes any opportunity to use this tour de force. The Parisians clearly do not find it tiresome.”  According to one theater historian, “The French male dancers, especially before the time of the ballerina sur la pointe, were the leading dancers throughout Europe owing to the dazzling virtuosity achieved by new techniques.” Dancing sur la pointe—on tiptoe—evolved in France and Italy around 1820, probably out of fair theater acrobatics. The first great ballerina of this modern technique was Maria Taglioni, who danced at the Paris Opéra from 1827 to 1837 and whose advent, writes another theater historian, meant not only “a victory for the ballerina over the male dancer,” but also “a victory for virtuosity.” 
Clearly, acrobatics, if not all of athletics, was on a roll. In the first half of the nineteenth century, the leading mime in France, Jean-Baptiste Deburau; the leading comic dancer in France, Charles Mazurier; the leading serious dancer in France, Jules Perrot; the leading actor in France, Frédérick Lemaître; and the leading actor in England, Edmund Kean, all started their careers in theater doing acrobatics.
In a variety of guises, acrobatics spread from the fairgrounds to every sort of public space, became popular with every class of society, invaded every sort of activity. Take tennis, for example, not lawn tennis, which scarcely existed, but “rackets,” a form of tennis that was and still is played on indoor courts such as the one at Versailles where the revolutionaries took their famous oath to continue meeting until they produced a constitution. During the Age of Revolution, the best rackets players in Europe were French. Although no formal championships had yet been established, Raymond Masson is generally considered to have been the best player from around 1765 to around 1785. He played so much better than most of his contemporaries that to make his games competitive he would often play two opponents at once, or play while mounted on an ass, or serve from inside a barrel, jumping in and out of the barrel between every stroke. Louis Labbé, a leading player of the 1830s and 1840s, played a match carrying the scorekeeper on his back. Edmond Barre, European champion from 1829 to 1862, used to make shots holding his racket in his weak hand, or hitting the ball between his legs, or striking the ball with the handle of his racket. Charles Delahaye, the second best player in France during the reign of Barre, played a match in the full dress uniform of a National Guardsman, with a pack on his back, a shako on his head, and a rifle and bayonet in his left hand.
Acrobatism in music was fortissimo. Paganini epitomized it in his story of “the Viennese fiacre driver who charged a man a ‘Paganinerl’ for a short trip. When the man asked how much that was, the driver answered: ‘A Paganinerl is five gulden—the price of a ticket to a Paganini concert in Vienna.’ To this the man responded: ‘You ass! How dare you charge five gulden for such a short distance! Paganini plays on one string; can you drive on one wheel?’”  Many of the anecdotes told about Paganini had circusy circumstances. According to one, Paganini astonished the composer of a violin concerto by sight-reading it using a reed cane in place of his bow. According to another, at a party in Paris given by Rossini he played a melody on a monocle cord stretched across the punch bowl. According to a third, he sight-read the first-violin part of a Mozart string quartet with the music upside down on his stand. Whatever the veracity of these three anecdotes, there is general agreement that Paganini had amazing sight-reading skill and dexterity. One musician wrote: “All violinists, some more often, some less, slip into discord, because a note can get away from anyone; but in the five concerts that I have heard Paganini give, I have not had the satisfaction of hearing him misplace a finger once, while he executed the greatest difficulties. His fingers were geometrical compasses.” 
Both Paganini and Liszt had plaster casts taken of their hands, which show long and, as contemporaries remarked, extremely flexible fingers. Liszt could play tenths with the same facility that most pianists played octaves, and he worked to make his fingers mutually interchangeable on the keyboard. Many of the distinguishing characteristics of Liszt’s playing—wide and rapid leaps, rapid note repetitions including trills and tremolos, chromatic scales in glissando, and interlocking hands—were digital acrobatics routines. There is no need to rehearse the previously cited contemporary accounts of his contriving technical challenges for himself or of his performing difficult passages at breakwrist speed. Liszt himself confessed in one of his “Lettres d’un bachelier ès musique” that as a young man on display in salons “I even went so far as insolently to add a quantity of embellishments and cadenzas” to the works of Beethoven and other composers. In this article, he denounced his earlier antics and renounced his career as “a musician in service to aristocrats, patronized and paid by them like a conjuror, or the canine-savant Munito.” 
The other side of the coin showed that conjurors, along with acrobats, had attained the social status of concert musicians. After all, prestidigitation was also digital acrobatics. With other forms of acrobatics, prestidigitation had been a mainstay of the fairs since before the turn of the eighteenth century. Many prestidigitators were empirics, too, and vice versa. Sleight-of-hand artists sold potions, elixirs, and panaceas to supplement their earnings, and purveyors of secret remedies made objects disappear, did the cups-and-ball routine, and performed card tricks to attract crowds of potential customers. Comus began his career doing prestidigitation and continued to do it after acquiring scientific and popular renown for his expériences and even after acquiring the titles “tutor of physics to the children of the king” and “physician of the king.” He gave lessons in prestidigitation to the duc de Chartres, rebuilder of the Palais-Royal and father of King Louis-Philippe. In the first half of the nineteenth century the best conjurors continued to be patronized by royalty, Comte by Louis XVIII and Robert-Houdin by Louis-Philippe, for example. And like the most successful acrobats, the most successful conjurors had their own theaters.
Both Maelzel and Robert-Houdin built mechanical acrobats. Maelzel’s slack-rope dancer perplexed another mechanician:
Robert-Houdin made a mechanical trapeze artist: “He executed tours de force on the trapeze, such as raising himself up by his arms into a handstand while making semaphore signals with his legs. In order to demonstrate that his mechanism was self-contained, my little Diavolo let go of the rope with his hands, hung upside down by his feet, and then left the trapeze entirely.” Could we be at all surprised to learn that despite the claims in these descriptions the two humanoids were probably controlled from the outside and thus not true automata? Such pseudo-automaton acrobats had already been exposed in the second volume of La Magie blanche dévoilée, published in 1785. Maelzel and Robert-Houdin themselves were the true “acrobats”—in the original Greek sense of “walkers on tiptoe”—for they had to make careful and deft movements to preserve their deceptions.
The most surprising thing about this little masterpiece of mechanics is the impossibility of figuring out how all of its various movements can be produced, because the automaton suspends itself now by one hand, now by the other, now by its knees, now by its toes, then it straddles the rope and twirls its body around it, thus abandoning one by one all of its points of contact with the rope, through which must necessarily pass whatever communicates movement to it.
There was also something acrobatic in the pseudo-automaton Chess Player: a Café de la Régence chess master, hunched over to fit within a small cabinet, reduced to near immobility for the space of several hours, and bent back unnaturally at the neck to see the board overhead—in short, a contortionist.
When Vidocq gave his exhibition of crime and crime detection paraphernalia in London, the Times wrote:
Vidocq developed athletic skills both as an outlaw, hiding in confined spaces, running on rooftops, and leaping from third-story windows, and as a detective, pouncing on suspects, holding them down, and handcuffing them. He learned how to fight with his fists in his youth, how to fence in the army, and how to kick-box using savate in prison. Most of the virtuosos had something athletic about them. A chess enthusiast reported that Labourdonnais could play “above forty games of chess at a sitting,” both because he played long hours without interruption and because he played rapidly. Carême boasted of his having “worked 53 extras without taking a day off” in 1805, of having constructed 150 pièces montées during the Consulate “and more than double that number” during the Empire. Paganini gave around 400 concerts during his European tour of 1828–34, including 140 concerts during one ten-month stretch in the British Isles. Liszt gave more than 1,000 concerts in 175 different cities, crisscrossing the Continent from Portugal, Spain, and Ireland in the west to Russia, Rumania, and Turkey in the east, between 1839 and 1847.
The principal curiosity in the collection will be found to be M. Vidocq himself, whose appearance is very much what might be anticipated by those who have read his memoirs or heard of his exploits. He is a remarkably well-built man, of extraordinary muscular power, and exceedingly active. He stands, when perfectly erect, 5 feet 10 inches in height, but by some strange process connected with his physical formation, he has the faculty of contracting his height several inches, and in this diminished state to walk about, jump, etc.
The virtuosos dispensed with external visual assistance in curious, and curiously similar, demonstrations of cerebral acrobatics. They played chess without a chessboard, identified crime suspects without the suspects’ presence, gave concerts without written music, and described objects without any sensory exposure to the objects. The blindfold performance shone a black light on cerebral agility.
Balzac reversed a cliché when he wrote: “There may exist between geniuses and other people the same distance that separates the blind from the seeing.” He likened geniuses not to seeing individuals in a blind population, but to blind individuals in a seeing population, attributing to geniuses “an inner vision superior to that of the seeing.”  The virtuosos based their inner vision on a highly developed memory and a highly structured system of technical knowledge.
Napoleon sometimes dictated three, four, five, six, even seven letters at once on as many subjects to as many secretaries, never getting confused and always having in focus the significant points of the current subject. According to one of his secretaries,
In order to have all the necessary information in his mind, Napoleon studied a continuously updated collection of livrets, or records booklets. The livrets laid out in tabular form the disposition and status of all the personnel and materiel belonging to a ministry, its requisitions and expenditures, and other similar sorts of data. Napoleon required each of his ministers to submit one or more livrets to him on a biweekly or monthly basis, and he used to call the livrets, particularly those from the war ministry, his favorite reading. According to another of Napoleon’s secretaries: “Each compartment of his memory had its supplement in a livret, and he made excellent use of this resource. His office thus became a veritable keyboard where all the strings of government seemed to end, and alone, with one secretary, he played whichever of them it pleased him to.” 
Napoleon used to explain the clearness of his mind, and his faculty of being able at will to prolong his work to extreme limits, by saying that the various subjects were arranged in his head, as though in a cupboard. “When I want to interrupt one piece of work,” he used to say, “I close the drawer in which it is kept, and I open another. The two pieces of business never get mixed up together, or trouble or tire me. When I want to go to sleep, I close all the drawers.” 
Labourdonnais, whose skill at blindfold play was explained by a contemporary, had “the power of actually setting up in his mind a chess-board and pieces, which remained throughout the game palpably visible to his organs of calculation.” Zukertort, a great simultaneous blindfold chess player of the later nineteenth century, “used to say that if he was playing 14 opponents, he would visualize 14 boards, each numbered, placed side by side in a row in separate closets, each closed by a door. Having made his move on board 1, the door closed and that of board 2 opened. In this way he passed from board to board, dismissing from his mind all the boards, except the one before him.”  To play not just blindfolded, but several games simultaneously, a chess master must be able to recognize and respond to most situations without having to think about them, in order to save time and effort for the particularly difficult ones. The anatomization of chess into recognizable patterns began with the beginning of openings analysis, centuries before the Café de la Régence dynasty. But Philidor, with his pioneering endgames analysis, advanced the project considerably.
Vidocq named Fossard as the artisan of the medal-gallery theft solely on the basis of a cut made by the thief in a panel of the gallery.
Vidocq’s ability to make such identifications was based on the files he kept on thousands of convicted criminals and on the efforts he made to memorize the faces of as many of them as possible. As an oracle of detection Vidocq had a predecessor in John Fielding, cofounder with his half-brother Henry of the Bow Street Runners, who lost his sight as a young man but was said to be able to recognize three thousand criminals by their voices alone.
Through experience, I ended up by acquiring in my occupation a sort of intuition that was almost like a prodigy. How often I struck with astonishment someone who came to me to report a robbery: he had scarcely mentioned two or three circumstances than I was already ahead of him; I either completed the story for him or without waiting for more detailed information I rendered this oracle: the guilty parties are such-and-such.
M. Prunaud, a fashion merchant on the rue Saint-Denis, had been robbed during the night. The robbers had broken into his store, from which they had removed fifty bolts of Indian-print fabric and several valuable shawls. The next morning, M. Prunaud ran to my office, and he had not finished telling the story of his misadventure before I named those responsible for the theft. “It could only have been committed by Berthe, Mongodart, and their cronies.”…I knew who their current fence was; I ordered a search of his residence and the merchandise was recovered.
The young Mozart gave a sort of blindfold performance, playing the harpsichord with a cloth spread out over both the keyboard and his hands. Paganini and Liszt were among the first to play whole concerts without written music. A system something like Napoleon’s must have been used by them, consciously or unconsciously, especially by Liszt, with his huge repertoire of performance pieces. Liszt gave other kinds of blindfold performances, too. He extemporized variations on themes given to him by members of his audiences. And he played long passages from pieces that he had never seen in written form and had heard only once, improvising improvements.
Robert-Houdin called his, or more accurately his son’s, blindfold performance Seconde Vue (second sight). Théophile Gautier described it in a review of the Soirées Fantastiques:
This trick above all others in Robert-Houdin’s repertoire impressed Gautier and, to judge from the number of magicians who imitated it, other spectators as well. Gautier, in writing that Robert-Houdin had “no communication” with his son during the trick, made precisely the inference the magician wanted him to make, an invalid one. Gautier meant that Robert-Houdin had no material communication with his son, for the magician was in speaking communication with his son the whole time. Nearly all observers failed to grasp that the magician’s apparently banal prompting of his son to guess the object was in a fact a sophisticated prompting of the correct answer by means of a prearranged code. Once again the performance depended on a highly developed memory and a highly structured system of knowledge.
Here is the expérience of M. Robert-Houdin: He takes his small son, a boy of around twelve years of age, makes him sit in a chair, bandages his eyes hermetically, moves away from him out into the audience, and asks the spectators for different objects: rings, watches, coins, or whatever they want to give him. The boy, with whom he has no communication, names the objects that are passed in the most secret ways to his father. He tells the value and the date of coins, the hour, minute, and second on the faces of watches, the maker’s name as it is engraved in their cases, the shape of rings and their monograms—incredible details! You are going to say “accomplices,” but one does not fill an entire hall with accomplices, and we are sure, for our part, of not being an accomplice of M. Robert-Houdin and yet the object given to him by us was named instantaneously.
In 1859, Jean-François Gravelet, alias Blondin, crossed Niagara Falls on a tightrope 160 feet above the rushing water and the twenty-five thousand spectators crowding its banks. He made several crossings that year, one of them blindfolded. Two years later he performed in London in the Crystal Palace, walking a tightrope while cooking an omelette on a portable stove, then while wearing shackles and chains, then while playing the violin, etc. Blondin at the site of industry’s Great Exhibition represented the meeting of two kinds of technical skill: technical skill embodied in the supreme acrobat of the century of mechanics and technical skill materialized in the latest machines of a society of clever hands.