handheld spectroscope built with optical glass. The composite prism and converging lens are mounted in a vertical viewing tube with a front slit to admit light. How it works Hold the spectroscope tube with the slit facing the light; a parallel beam is generated from the slit and converging lens. When this parallel beam passes through the prism, the dispersion spectrum is visible directly. What you will see With fluorescent light, the spectrum appears as a continuous background with mercury lines (three straight lines) standing out. What this lets you do Understand how we determine the composition of matter and distant stars by analyzing light spectra. You can read about spectral analysis in textbooks and now observe the Sun's emission spectrum firsthand. Safety and usage When observing sunlight, use sunlight reflected from a mirror; do not directly face the sun. Use scenarios Classroom or science club demonstrations of light spectra using fluorescent lamps or other light sources. Handson study of the Sun's emission spectrum to illustrate spectral lines. General exploration of how different light sources produce spectra in a home or school setting.