200-inch Hale Telescope
HEIGHT OF DOME: 135 FT. DIAMETER: 137 FT. WEIGHT: 1.000
TONS. WEIGHT OF TELESCOPE: ABOUT 500 TONS.
THE MIRROR, MOUNTED IN THE LOWER END OF THE TELESCOPE,
WEIGHED 20 TONS BEFORE GRINDING AND POLISHING. 14 TONS
AFTER. IT IS 200 INCHES IN DIAMETER. 24 INCHES THICK AT
THE EDGE, 20 INCHES THICK AT THE CENTER. THE UPPER
SURFACE OF THE MIRROR IS COVERED BY A THIN BUT BRIL-
LIANT COAT OF ALUMINUM, IS CONCAVE AND FOCUSES THE
LIGHT OF A STAR IN THE SAME WAY AS A LENS. PC 10
MOUNT WILSON AND PALOMAR OBSERVATORIES PHO TO GRAPH.
E 4693
