Abridged Scientific Publications Volume 4-6

Abridged Scientific Publications Volume 4-6

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1922 edition. Excerpt: ...measurements of the same pairs made with plate wet and plate dry. It is clear that this effect can be differentiated from the "attraction" of the latent image already discussed, and from the "repulsion" of the Kostinsky effect discussed in a later paragraph. A test-object composed of ten artificial double stars, all of equal size, was photographed on Seed 30 plates, the separations being adjusted so as to reproduce conditions obtaining in practice. It was photographed in a precision camera reducing 20 diameters. The separation of the close pair is 0.052 mm. and of the widest pair 0.104 mm. The average diameter of the images is 0.04 mm. Five exposures were made on each plate and measured wet and dry. The plates were developed in several developers, including the staining: pyro, pyro-metol, and caustic hydroquinone; and the non-staining: hydroquinone and metol-hydroquinone. For all developers and all pairs the contraction was found to be identical, avcraging.0016 mm. Pyro-metol showed an exception, the contraction in this case being four times greater. The series of measurements on the double star group furnishes information on the Kostinsky effect, as well as on the gelatine effect just considered, for measurement of the separation of the double stars on the test-plate itself, assuming no distortion in the optical system, gives the relative values of the separation of the images of the test-plate. For this comparison only the pairs aa' and jj' need be considered. The results are: l'l11T1. Separation of centers of aa' in test-plate.......... 2 000 Separation of centers of jj' in test-plate......... 1.022 Photographed aa' (measured wet).................. 0.1049 Photographed jj'...show more

Product details

  • Paperback | 198 pages
  • 189 x 246 x 11mm | 363g
  • Rarebooksclub.com
  • United States
  • English
  • black & white illustrations
  • 123677325X
  • 9781236773258