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Bryn Mawr College monographs . centrated into an image on ^211 rT^/^^°^^^^^^^ ^^^^-PP- ^50,261 andin ^ K i- °^ °^ ^^^ concentrated into this image can easily be deter- uned by direct measurement with our radiometric apparatus for any of the wave-ngths used by us as stimuli, and the amount per unit area be estimated; further ifl^c^ rj^^- Tt ^ ^ ^^^^ ° ^ ^^^^ ^^ ^ l^ter paper, lee 254 C. E. FERREE AND GERTRUDE RAND gives a light which changes comparatively little through longintervals of time. It has the advantage, moreover, that itsshape well adapts it for use with the slit of the spectroscope,
Bryn Mawr College monographs . centrated into an image on ^211 rT^/^^°^^^^^^^ ^^^^-PP- ^50,261 andin ^ K i- °^ °^ ^^^ concentrated into this image can easily be deter- uned by direct measurement with our radiometric apparatus for any of the wave-ngths used by us as stimuli, and the amount per unit area be estimated; further ifl^c^ rj^^- Tt ^ ^ ^^^^ ° ^ ^^^^ ^^ ^ l^ter paper, lee 254 C. E. FERREE AND GERTRUDE RAND gives a light which changes comparatively little through longintervals of time. It has the advantage, moreover, that itsshape well adapts it for use with the slit of the spectroscope,i e the shape is such as to make it possible to utilize for theillumination of the face of the prism a relatively large pro-portion of the light emitted. Also by increasing the lengthof the filament and collimator slit, it is possible to increasein direct ratio the amount of light falling on the face of theprism. When in use, in order that no light shall be lost inpassing through one or more condensing lenses, the filament. F>G. .. Showing the Apparatus Grouped for Work-hght source, sp=ros op -thermopile, and rotary eampimeter with its auxiliary lens system. In -^^^^^1^^stray light either from the general illumination of the room or by -fl«° ^°^the Nernst glower be eliminated, the spectroseope and lens system are, -^ m seenclosed from just in front of the Nernst to the camp>meter screen m a is mounted as closely as possible to the jaws of the slit. It isshown in position for work at {N) in Figs. 2 and 3- ^^^filament is mounted in a lamp socket fastened to an upright SPECTROSCOPIC APPARATUS 255 (^.). In order that the height of the filament shall be ad-justable upright consists of a short rod sliding in a tubefitted with collar and set screw {B) which permits of a move-ment of the socket up and down, also to right and left Theupright {A,) IS fastened to the horizontal support (Z),) ex-
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Keywords: ., bookauthorbrynmawr, bookcentury1900, bookdecade1900, bookyear1901