Concave mirrors focus candle flame on thermopile across bench. (same as 650)

Concave mirrors and horn thermopile senses candle across room. (Same apparatus as X) Concave mirrors are positioned at opposite ends of the lecture table. A candle is positioned at the focal length of one mirror. A horn thermopile is positioned at the focal length of the opposite mirror. The candle flame is thus focused on the elements of the thermopile (which develops about 1 mv. per degree). The signal is amplified and projected onto a screen. Note: The multimeter produces heat and can skew results, so it should be placed outside the mirrors. Leave the amplifier on for the entire demo.