In this piece, fourth of the five Images Miroirs by Maurice Ravel, there are three “double glissandi”, ascending then descending, over white keys of the piano. One of them uses a fourth interval, the next one uses a third interval.
What fingers would you use to perform those glissandi?
An edition hosted on IMSLP here (PDF page 40) indicates that you should use 4-2 for the ascending glissandi, and 3-1 for the descending ones.
I'm personally not a fan of the 3-1 fingering, because it's harder to rotate the hand so your nails impact the next key (Doing that makes glissandi hurt MUCH LESS on pianos with a stiff action). On the other hand, it does prevent you from having to pop your elbow up to play the descending glissandi, like you would have to if you were to use 4-2 on the descent. I'm 100% a fan of the 4-2 ascending fingering.
