Of course, in the beginning I have a method. A knowledge of correct hand position and of many different qualities of touch which I use and which give a never-ending variety to the tone must be learned before one can go very far. The fingers must have acquired an unyielding firmness and the wrist, at the same time, an easy pliability in order to avoid hardness of tone. Besides this, there are rules for singing, which apply to melody playing on the piano to just as great an extent as to melody singing in the voice.
— Theodor Leschetizky, the greatest piano teacher of the 19th century

19th Century Devices

Outstanding minds of the 19th century recognized the necessity of mechanical aids for teaching piano technique, to prevent possible imperfections in the physical approach of the piano player. The first piano device, the Chiroplast, was invented by John Bernard Logier (1777-1846) in 1814. It was endorsed by Muzio Clementi and manufactured by Clementi's piano factory. Carl Czerny expressed a high opinion concerning its value as a retraining tool: "In modern times several mechanical aids have been invented towards attaining a well regulated facility and flexibility of finger; as for Ex. the Chiroplast, the Hand-guide, the Dactylion, etc.: To such Pupils as have at first been spoiled by improper instructions, these machines may be of great, and striking utility."[1] Other contemporaries praised the Chiroplast noting that it "helps one to relax and set the mind at ease."[1] Schools based on work with this device were opened in England and India. The Prussian government adopted Logier's system in 1821 and Logier, himself, supervised many state-supported academies in Germany.

The idea for a scientific approach to the mechanics of piano playing continued into the Romantic period. Friedrich Kalkbrenner (1785-1849) became an enthusiast of the Chiroplast and invented his own device, the Hand-guide. Kalkbrenner justified the advantage of his device: "What hinders beginners is the extreme tension which they show in all of their practice... With the Hand-guide, it is impossible to contract bad habits... It keeps people from making faces, from playing from the arm or the shoulder; it makes the fingers independent, corrects the position of the hand which it makes as graceful as possible."[1] Kalkbrenner's device became very popular in Paris in the 1830's, selling more than 31,000 copies in Paris alone. 

Young Franz Liszt, in his Paris studio, used a modified version of Kalkbrenner's device for his students: "Liszt devised a brace made from mahogany, and its purpose was to keep the forearm motionless; this brace was attached to the piano and was nothing more than a device invented by Logier and perfected by Kalkbrenner."[2] Camille Saint-Saëns, who was regarded as a piano virtuoso as well as a great Romantic composer, also started his study of piano technique using Kalkbrenner's Hand-guide: "I also was put upon regime of the guide-mains... It was not only the strength of finger that one acquired by this method, but also production of tone quality by the finger only, a precious expedient that has become rare in our days."[1]

[1] Gerig, Reginald R. Famous Pianists & Their Technique. Washington-New York: Robert B. Luce, Inc., 1974.

[2] Mach, Elyse. The Liszt Studies. New York-London: Associated Music Publishers, 1973.