This elegant crystal swan gravy or sauce boat is part of the Pall Mall glassware pattern by Duncan and Miller from the 1940s. It has a swan shaped handle and heart shape bowl. The base is sterling (most are marked Sterling but this one isn't, or it was impressed too faintly to see). The gravy is 4 inches wide by 4-1/2" to the spout by just over 3-3/4" high to the top of the handle and comfortably holds one cup. In excellent vintage condition with no damage. The swan's neck looks distorted due to reflections of the cup rim - there are no cracks or bubbles.
Duncan Miller Swan Gravy Sauce Boat Sterling Base