Lewis Swift discovered NGC 4155 = Sw. I-21 on 6 Apr 1885. Although his description "vvF, vS" is not very helpful, his position is just 6 sec of RA east and 1' south of UGC 7172.

400/500mm - 17.5" (5/11/02): fairly faint, fairly small, round, 1.0' diameter, moderate concentration to a small bright core. Two mag 10 stars are 9'-10' SW near the edge of the 20' field. Located 31' NNE of gc NGC 4147.

Notes by Steve Gottlieb