This is an antique Union Glass Lomax Oil Guard finger lamp. The burner was made by E. Miller & Co. The foot is marked ""Trade Mark Oil Guard Lamp" & Patd Sep 20 1870" deals. The lamp stands 13-1/2" (34.3 cm) to the top of the chimney and 6-3/4" (17.1) tall to the top of the burner. The font is approximately 3-3/4" (9.5 cm) in diameter. The burner does have a slight lean to it but we believe that it can be easily brought to level. We have owned the lamp for close to 30 years and it never bothered us enough to deal with it. Otherwise, the item is in excellent condition without chips, flea bites, or scratches. The wick knob turns easily.
Our selection of glass made before 1950 is shown here:
https://www.etsy.com/shop/soflacollectors86?ref=hdr_shop_menu&sort_order=date_desc§ion_id=10515937
Product code: Union Glass Lomax Oil Guard Finger Lamp (Patd Sep 20 1870) w E. Miller deals Burner