with an illuminated blown-glass base

Alastair Duncan, Tiffany Lamps and Metalware, Woodbridge, Suffolk, 2007, p. 137 (for the shade and base pairing)

Overall very good condition. The shade presents with an overall slightly more subtle color palette when viewed in person compared to the catalogue illustration, which is slightly over saturated. The shade with approximately 8 hairline cracks dispersed throughout. One white tile in the lower geometric border with a crack that shows slight movement but is secure within its setting. One blue tile in the geometric border with a crack with a small associated loss, not visually detractive. The shade with three leaf tiles that are possibly replaced with period Tiffany glass. The upper shade ring appears to have been reset at some point in the history of the piece. The internally-illuminated base is in overall very good condition. The base glass with scattered minor air bubbles and particulate inclusions inherent in the making and not visually detractive, and with scattered minor surface scratches. The bronze collar, arms and foot with scattered surface scratches and abrasions consistent with age and gentle handling. The shade arms with some minor losses to the patina. The foot with scattered minor discolorations. With an original interior socket and later replaced exterior socket. With a later-added base switch. A harmonious shade and base pairing displaying a complementary color palette.
In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective qualified opinion.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING CONDITION OF A LOT, ALL LOTS ARE OFFERED AND SOLD "AS IS" IN ACCORDANCE WITH THE CONDITIONS OF SALE PRINTED IN THE CATALOGUE.