A Pair of Concave Mirrors Set Facing Each Other

| View Cart ⇗ | Info

“If a pair of concave mirrors be set facing each other, as shown in figure 7, and a source of heat be placed in the focus of one, a thermometer in the focus of the other will quickly show a rise in temperature though the mirrors are many feet apart.” Louis Derr, 1911


Derr, Louis Cyclopedia of Engineering (Chicago, IL: American Technical Society, 1911)


TIFF (full resolution)

2400×1439, 356.1 KiB

Large GIF

1024×613, 49.5 KiB

Medium GIF

640×383, 24.5 KiB

Small GIF

320×191, 8.7 KiB