McClure's Magazine, Vol. 6, No. 5, April, 1896

The Project Gutenberg eBook, McClure's Magazine, Vol. 6, No. 5, April, 1896, by Various
Transcriber's Note: The Table of Contents and the list of illustrations were added by the transcriber.

1 and 3. Flint glass prism (very opaque).
2. Quartz prism, showing transmission of the rays through the thin edges.
4. Prism of heavy glass, more opaque than flint glass.
5. One-cent coin, copper.
6. Five-cent coin, nickel.
7. White-crown glass, 1-1/2 millimetres thick.
8. Blue crown glass, 2 millimetres thick.
9. Yellow crown glass, 1-1/2 millimetres thick.
10. Crown glass, 1 millimetre thick, covered with a very thin layer of gold.