This crazy little oil lamp has a trough-like appendage on the lid, as if something would be laid in it with the end extended out over the flame. Some have suggested that it could have beenused for incense but that doesn’t make sense to me as the incense would a) not need a continuous flame and b) would burn back from the flame and 2” of ash would not be held by the trough. It has hallmarks, but not that I can decipher. I’ve posted the hallmark question separately but if it’s helpful for determining the function of this lamp, there is a tombstone shaped mark with an unidentified symbol in it, a square mark with a possible I or T, slash, and a possible C or O. Further to the right of those marks is an H - no cartouche or shape around it, just the letter. On the rim of the lid and on the base of the lamp font, the number 10 is stamped.