The idea is the same as in the scale. The problem which presents itself is how to smooth over the jump between G and C. On the accompanying diagram I attempt to show, by the small lines underneath the notes, how the finger which falls just before the thumb (in this case it is the 3rd, on G) is raised from the wrist and inclined towards the direction to which the hand has to proceed.

Showing the 3rd finger placed with raised wrist for passage of thumb.

This 3rd finger should be placed upon the note exactly one and three-quarter inches length away from the edge of the key towards the back of the keyboard, and the thumb should fall underneath it upon C, just the length of its own nail away from the key edge, that is about a quarter of an inch. Thus :

Arpeggio. C major. Right hand ascending,
showing relative positions of the thumb and finger.

Coming down the position is reversed, as follows: The thumb falls upon the note at the one and three-quarter-inch position from the edge of the key, when it is lifted up by the wrist movement, and the 3rd or 4th finger, as the case may be, then falls over the thumb on to the note below, about one-quarter inch from the edge of the key. Thus :

Arpeggio. C major. Right hand descending (starting from right of diagram),
beginning with 2nd finger on E, so as to show relative position of the fingers used.

The movement of the wrist makes for smoothness at the jump and helps to prepare the hand for the next position. The principle is similar in both hands as in the scales, only reversed in the left; that is to say, when the left hand ascends the thumb is lifted by the wrist and placed one and a quarter inches from the end of the key, while going down it is the 3rd or 4th finger which assumes that position, the thumb falling on the key at the quarter inch from the end of the key, as in the ascending right hand arpeggio.

Arpeggio. C major. Left hand ascending (starting from left of diagram),
beginning with the thumb on C, so as to show the relative positions of the other fingers.

Arpeggio. C major. Left hand descending (starting from right of diagram),
beginning with the 4th finger on E, so as to show the relative position of the fingers used.

Exactly the same rules apply in all the varieties of arpeggio playing.

It is absolutely imperative for students who wish to acquire any proficiency in pianoforte playing to practise a good amount of scales and arpeggi every day. Therefore, he who starts his work regularly and thoroughly every morning with a course of scales and arpeggi will gradually find a fine easy technique coming to him and a mastery over the keyboard which will be of inestimable advantage to him when he starts investigating the treasure house of pianoforte literature.