Lewis Swift discovered IC 691 = Sw. VII-17 on 17 Apr 1888 and recorded "pF; pS; R; forms right angle with 2 st." His position is 1.5' too far west (within his usual errors) and the description is a perfect match.
400/500mm - 17.5" (3/19/88): fairly faint, very small, bright core, slightly elongated.
Notes by Steve Gottlieb