For your consideration I offer a mid 19th century solar or astral oil lamp that is probably converted to use for kerosene. The font is hollow like a regular kerosene font and the burner collar is standard 7/8 inch No. 1. I can find no evidence of this top opening of the lamp being altered but I think it must have been to convert it.The bottom of the font is solid as well.The air vent is just under the font. I believe this could be one of Henry Hooper company lamps. It is a petite small size, measuring only 8 inches tall to top of collar. The width of the lamp where the shade ring would rest on that band around the shoulder is 4 3/16". I noted three small spots of solder spaced equally around that ring where I think the shade ring was spot soldered on at one time.. There is a lead weight in the bottom of the foot that still has what I believe is the original added covering to prevent scratching the furniture. The lamp is all in good shape. I also let some water sit in the font for a few hours and nothing leaks. Send an email if you have any questions and check my shop for other items of interest.