Spectroscope is a replica diffraction grating instrument with a scale to show approximate wavelengths in Angstrom units. Housing is a single-piece aluminum casting mounted on a nickel-plated steel post supported by a cast iron tripod base. In use, the white face reflector is positioned to give a small amount of back lighting to a photographic film scale, so that it may be clearly seen against the superimposed image of the spectrum. To observe solar spectrum, use a cloud and the adjustable slit. Will detect Ca, Pa, Sr, Li, K, Na, Rb, Cu, etc. by flame emission. As slit is closed, prominent Fraunhofer lines appear. In lab, source is placed in front of slit and light from lamp directed in scale. 16" x 10" x 9"; 7 lbs.