6-inch, f/8 concave telescope mirror
Date: circa 1960
Inventory Number: 1997-1-0043
Classification: Mirror
Maker: American
User: Oak Ridge Station (1931 - 2005)
User: George R. Agassiz Station, Harvard (1951 - 1982)
User: Harvard College Observatory (founded 1839)
Cultural Region:
Dimensions:
13 x 21 x 18.8 cm (5 1/8 x 8 1/4 x 7 3/8 in.)
mirror diameter: 16 cm (6 5/16 in.)
Accessories: dust cover
DescriptionThe circular 6 1/4-inch concave mirror has front-surface silvering. The mirror curvature is very slight.
The cell consists of a thick brass collar and cast ring for the rear. The central part of cell's rear is flanged around a circular opening, which reveals a membrane across the back of the mirror. Three threaded sleeves protrude from the casting of the back and accept tip/tilt screws with winged heads. One screw has a mounting rod and two brackets with locking screws attached to it.
At the front of the cell, there are small wedges holding the mirror in place. The numerals 1, 2, 3, 4 have been handwritten the wedges. These match up with numerals penciled on the cell.
The numeral "1" is cast into the back of the cell.
The mirror has a tin dust cover to protect it when not in use. The cover has a coppery handle. Some words were written in white chalk or crayon on the circumference of the cover. These are very hard to read, but may read, "CRITERION 4' F. L."
All cell fittings and dust cover are colored black.
The cell consists of a thick brass collar and cast ring for the rear. The central part of cell's rear is flanged around a circular opening, which reveals a membrane across the back of the mirror. Three threaded sleeves protrude from the casting of the back and accept tip/tilt screws with winged heads. One screw has a mounting rod and two brackets with locking screws attached to it.
At the front of the cell, there are small wedges holding the mirror in place. The numerals 1, 2, 3, 4 have been handwritten the wedges. These match up with numerals penciled on the cell.
The numeral "1" is cast into the back of the cell.
The mirror has a tin dust cover to protect it when not in use. The cover has a coppery handle. Some words were written in white chalk or crayon on the circumference of the cover. These are very hard to read, but may read, "CRITERION 4' F. L."
All cell fittings and dust cover are colored black.
Signedunsigned
Inscribedinscribed on side of cover: [CRITE]RION 4' F. L.
ProvenanceHarvard College Observatory, Agassiz Station, transferred to CHSI