. Bulletin. Science. /â¢â /,,,â J. ^IMMMMII^ Figure 76.âDetails of the Siemens and Halske dynamo of 1876. For clarity, the brushes have been omitted in the drawing. From R. W. H. P. Higgs and J. R. Brittle, "Some Recent Improvements in Dynamo-Electric Apparatus," Minutes of the Proceedings oj the Institution of Civil Engineers, 1878, vol. 52, pp. 36-98, pi. I. of the Gramme dynamos is quite close to that of the Siemens dynamo as measured by Hopkinson and others. Up to this point, three-quarters of the way through the 19th century, the electric light was possible, but it was not very
. Bulletin. Science. /â¢â /,,,â J. ^IMMMMII^ Figure 76.âDetails of the Siemens and Halske dynamo of 1876. For clarity, the brushes have been omitted in the drawing. From R. W. H. P. Higgs and J. R. Brittle, "Some Recent Improvements in Dynamo-Electric Apparatus," Minutes of the Proceedings oj the Institution of Civil Engineers, 1878, vol. 52, pp. 36-98, pi. I. of the Gramme dynamos is quite close to that of the Siemens dynamo as measured by Hopkinson and others. Up to this point, three-quarters of the way through the 19th century, the electric light was possible, but it was not very practical commercially. Serrin's regulator could be used but it was so delicate that adjustment was difficult, and it was both mechanically and electrically complicated. Only one arc lamp could be used as a load in the circuit of the generators then in use; to place two regulators in the same circuit would, in effect, prevent either one from working. Moreover, the arc light was too bright for any purpose other than illuminating large areas, some means had to be found of "subdividing" it so that the brilliancy of a single arc lamp in a single circuit could be spread over many lamps of weaker intensity in the same circuit. Practical electrical generators had been invented, but the initial expense of plant installationâwhich was that of a gas or steam engine plus the electrical generator and the other electrical equipment that could only be used for a single lightâwas prohibitive for ordinary purposes (figs. 78, 79). Some means had to be found whereby such a large capital investment could be used for a number of lights that would be of lesser intensity than 392 BULLETIN 228: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Smithsonian Inst
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