Signedunsigned
Inscribedon side of box in white letters: 9" mirror
on lid of box in black crayon: MIRROR / OF / DRAPER / HELIOSTAT / [9 IN. MIRROR / IN CELL]
Historical AttributesHenry Draper used a heliostat with a secondary mirror for his spectroscopic studies in his New York laboratory. The instrument was made by Alvan Clark & Sons. This could be part of that instrument.
ProvenanceHenry Draper, New York and Hastings-on-Hudson; gift to Harvard College Observatory at his death; found at Agassiz Station of Harvard College Observatory; transfer to CHSI.
Related WorksAllan A. Mills, "Portable Heliostats (Solar Illuminators)," Annals of Science 43 (1986): 369 - 406.