Here's is an Atterbury Prism and loop oil lamp as seen in Thuro I, 143G. This one has a different base. The patent Sept 29, 1868 screw on connector made it possible to use the same font with a variety of bases. It was quite a popular innovation of the time. This one is excellent with no chips, cracks or discoloration. Has good wear on base bottom and one tiny chip on the underside of base, not seen when lamp is on a table. Nice original fine line brass collar. Sold with a No. 1 Queen Anne burner and an old pearl top chimney. Measures 10" H to top of collar.