The Jelly Knife was designed to slice and serve jelly - everything from aspics, to clear fruit jellies, to Jello. A few patterns would have 2 or 3 different size jelly knives. Also, some patterns have aspic servers as well as jelly knives. They range in length from 7 to 9 inches.
Chrysanthemum by Durgin (7 1/2 inches)
Georgian by Towle (7 3/4 inches)
Japanese by Tiffany (9 inches)