TABLE II. Values of the Constant for each Plate from Measures of the Four Comparison Stars, 8-9 Mag. The results for photographic magnitude of the four comparison stars may serve to show the degree of consistency which may be expected in determinations of magnitude deduced from measures of diameter of star-disks. Royal Observatory, Greenwich: 1892 November 11. Estimations of Magnitude of Nova Auriga, made with the Barclay Equatoreal, at the Radcliffe Observatory, Oxford. (Communicated by E. J. Stone, Esq., M.A., F.R.S., Radcliffe Observer.) Nova possibly a trifle brighter than on September 13. Moonlight. Images not sharp with any power, but § is visible. Observer. Estimations of Magnitude of Nova Aurige.-(continued). a, k, h, g, i The contrast between the Nova and a is, I believe, stronger to-night than on October 17. 85 9.6 a, k, h Observers: W., Mr. W. Wickham; R., Mr. W. H. Robinson. Nova's image is dull. The image of the Nova is rather dull. There is a slightly greater difference in magnitude between the Nova and a with power 180 than with 85. The comparison star h was generally observed to be or of a magnitude brighter than k. The exceptions were:-September 24, fainter than k; September 30, equal to ; October 19, 0'2 fainter than ; October 25 and 29, equal to k. The adopted magnitudes of the comparison stars are given in the Monthly Notices of the R.A.S., vol. lii., page 431, and depend fundamentally upon the magnitude assigned by Argelander to the star k (D.M. + 30°, No. 924), |