is cama ge rr ee ¢ Copyrighted, 1887, by Munn & Co.J NEW YORK, NOVEMBER 5, 1887. | $3.00 per Year. Vol, LVII.—No. ual {NEW sERIEs.] … EXTERIOR OF MR. EDWARD WESTON’S RESEARCH LABORATORY, NEWARK, N. J. electrical testing and experimental apparatus, and a determine their illuminating power. In testing them they are photometered in various positions, in order to obtain an average result or ‘‘ the spherical illuminating power.” In…
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