...unsen's cells arranged consecutively, an are 7.8 inches in length was obtained; and when the 600 cells were arranged in six parallel series, a still more powerful light was produced. According to Fizeau and Foucault, the intensity of the electric light with a battery of 46 pairs of Bunsen burners was 235, that of the sun being taken at 1,000, while with 80 pairs it was but 238. During the excava...