Artificial harmonics may also be produced at the distance of a minor third, but these speak with difficulty.
At an octave:
In like manner on the higher strings.
In the lower positions those at the octave necessitate a wide stretch between the 1ˢᵗ and 4ᵗʰ fingers, rendering them impossible for small hands.
Double harmonics.
Both natural and artificial harmonics may be played as double stops. The former speak best, the latter being more difficult. They require very thin stringing.