![](http://www.alamy.com/thumbs/6/F2BBE103-1411-4131-89BB-7A824D90F5C5/2AG44CC.jpg)
. The Astrophysical journal. - the feasibihty of the method but. Fig. 12.—Extra-focal measures of magnitudes of stars of the Pleiades (thedesignation is that of Bessel). the valuable results which may be obtained by such methods ofmeasurement, especially in the study of laboratory spectra.^ Theapparatus under present consideration, when provided with a Atmalen der Physik, 39, 705, 1912.^ Astrophysical Journal, 39, 213, 1914. THERMOPILE IX PHOTOGRAPHIC PHOTOMETRY 283 micrometer-screw stage, becomes at once adapted to such measure-ments. When so used, the small circular diaphragm is replaced bya
. The Astrophysical journal. - the feasibihty of the method but. Fig. 12.—Extra-focal measures of magnitudes of stars of the Pleiades (thedesignation is that of Bessel). the valuable results which may be obtained by such methods ofmeasurement, especially in the study of laboratory spectra.^ Theapparatus under present consideration, when provided with a Atmalen der Physik, 39, 705, 1912.^ Astrophysical Journal, 39, 213, 1914. THERMOPILE IX PHOTOGRAPHIC PHOTOMETRY 283 micrometer-screw stage, becomes at once adapted to such measure-ments. When so used, the small circular diaphragm is replaced bya small adjustable slit, which all but touches the under and film-side of the spectral plate to be measured. Arrangement is thenmade whereby a sliding platform moved by an accurately cutmicrometer-screw may be attached to the main stage of the instru-ment. The spectral plate is held to the latter by clips in the usualmanner, \\dth the film down and in close contact mth the slit-diaphragm. The spectrum is then exposed by setting themicrometer-screw for a given
Size: 1378px × 1812px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectspectru, bookyear1895