These are certainly essential to a correct and agreeable rendering of a piece of music: the compositions which are to be performed ought, however, never to demand the exercise of all the mechanical skill which has been acquired, for in that case, by the struggle with mechanical difficulties, only embarrassment, discouragement, and anxious haste are apt to take the place of boldness, confidence in one's self, and command of the music.

It is the duty of teachers, in choosing studies for the improvement of technique, to select only such as are within the mechanical powers of the pupil, in order that he may make steady progress, and may acquire a pure and delicate style of execution, retaining at the same time a lively interest in his pursuit.

But why has the acquirement of this technique been usually unsuccessful?
1.

Because you begin to acquire it too late.

In order to gain facility and flexibility of the fingers and wrist (which a child in the sixth or seventh year, with a skilful teacher, may acquire in four lessons), from fifteen to twenty lessons, according to the construction of the hand, are necessary with persons from ten to fourteen years old.