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The 338 photographs shown in the following fifty-seven pages of the Atlas all have a notch marking north. West is 90° clockwise. The prints represent magnifications from the original plates of 1x, 2x, 4x, 6x, and 10x. Since all the 200-inch plates in this program were taken with the Ross f/3.67 corrector lens, the original plate scale is 11".1 / mm. The scales on the Atlas prints therefore vary from 11" / mm to 1'.1 / mm. The natural scale (1x) of the few prints from Schmidt plates is 67" / mm. In reproduction of the large-size photographic edition, all these scales have been reduced by a factor of 0.97.

About one-third of the prints were made by an automatic (fluorescent screen) dodging process, i.e., by compressing the density range so that one can see very faint features and yet see into the brighter inner regions on the same print. In some cases the automatic dodging has introduced slightly lighter halos around the stars.


Col. 1: Identification number in this catalogue. See Diagram 1 for arrangement of types of objects.
Cols. 2-3: Right ascension and declination of objects for 1970 epoch. Positions are from three sources: (1) NGC positions where available. If more than one NGC object is pictured, the position of the westernmost (smallest number) is given. (2) Positions from 200-inch dial readings calibrated by objects with known positions. (3) Measurements on 48-inch Sky Survey plates (whenever possible, differential measurements from nearby NGC objects). The final accuracy of these positions, from cross-checking the different methods, is on the average better than ± 0.m2 in R.A. and ± 2' in Dec. A few positions are from Vorontsov-Velyaminov.
Col. 4: Designation. NGC or IC numbers are given when object has one, otherwise designation is blank.
Col. 5: Plate number. PH designates 200-inch Hale telescope; PS designates 48-inch Schmidt. Plates taken by Arp unless designated B = Baade, Bm = Baum, M = Minkowski, S = Sandage, Z = Zwicky.
Col. 6: Exposure in minutes.
Col. 7: Kind of emulsion used - `bk' designates baked and `lb' designates lightly baked; `exp' designates experimental.
Col. 8: Identifies the filter used, if any.
Col. 9: Seeing.
Col. 10: Magnification (usually varies from 1x to 10x) in which 1x = 11" / mm. Asterisk denotes 48-inch Schmidt scale in which 1x = 67" / mm.
Col. 11: Source. As far as can be determined, the person who first noticed the peculiar object is named. Vorontsov-Velyaminov (VV) numbers are given when they exist. DDO is David Dunlap Observatory.
Col. 12: Remarks on objects shown in photographs. Major peculiarities are described in Diagram 1; additional peculiarities and remarks are noted here.

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