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Charles William Scott Crawley
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Photometry And Measurement Of Optical Pulse Characteristics
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Spectrometry And Color Measurement
(AREA)
Testing Of Optical Devices Or Fibers
(AREA)
Abstract
19,087. Crawley, C. W. S. Sept. 7. Photometers.-A slightly-curved screen c receives light from a standard lamp b, while the light to be tested falls upon a surface e having a small aperture or slit f. The screen c is then turned by an external handle, carrying a pointer working over a scale h, until the slit f appears neither light or dark. Preferably an amyl acetate lamp is employed with an adjustable flame, which can be brought to the required height opposite a pointer viewed by means of a reflector j.
II. The Bakerian Lecture. On the composition and analysis of the inflammable gaseous compounds resulting from the destructive distillation of coal and oil, with some remarks on their relative heating and illuminating powers