Dunno where the pic came from I just google - image'd for a traditional horn. I think mine came from Nauticalia & is bigger & straighter than that one & has no chain. It also has a suitable patina of verdigris now so it really does look the part on my old tub.
If I ever get to PD I shall use it to alert the Major of my arrival, hopefully in the wee small hours, so that he has time to get all the locks & chains off his drinks cabinet by the time the sun is over the yard arm.