Calendar: 1872-1873 Page 299

298 EVENING CLASSES IV Vibrations of Rods Plates Membranes Relation of the Mode of Vibration to the Pitch of the Note Reed Instruments Musical Intervals Combinations of Sounds Intensity of Sound Resonance Organ Pipes Singing Flames Beats Interference of Sound Harmonics Optical Representation of Vibratory Motions VI The Propagation of Light Methods of Measuring its Intensity Theory of Shadows Velocity of Light Aberration The Undulatory Theory VII Reflection of Light from Plane and Curved Surfaces The Heliostat Caustics formed by Reflection Refraction of Light Total Reflection Atmo- spheric Refraction Prisms VIII Measure of Indices of Refraction Lenses Compo- silion of White Light The Solar Spectrum The Oxy-hydrogen Light The Electric Light IX Spectra of Incandescent Solids Liquids and Gases Absorption of Light Constitution of the Sun and of various Fixed Stars Heat Light and Chemical Spectra Emission of Light The Origin of Colour in Bodies Optical Instruments The Eye and Vision Irra- diation XI Transformations of Radiations Phosphorescence Change produced by Heat Fluorescence Chemi- cal Effects of Light Photography XII Interference of Light Colours of Thin Plates Newton's Rings Diffraction Coloured Fringes XIII Polarization of Light by Reflection by Refraction and by Passing through Crystals Norremburg's Apparatus