Extensions.
The use of extensions, that is, the fingering of certain notes which are foreign to the position in which the hand is placed, is of more frequent occurrence in the thumb positions than in the lower range of the instrument. To a great extent these have to be studied as special passages. However, each passage of this description thoroughly mastered, will make similar passages easier and assist in giving a greater command over the fingerboard. To acquire a general knowledge of these extensions, the student may practise a series of "running arpeggios" in the various keys, similar to those given by Coward Klee in his arrangement of scales for 'cello. The student may play them in three or four octaves according to the possibilities of the instrument.