William Herschel discovered NGC 6142 = H III-892 on 30 May 1791 (sweep 1015) and recorded "eF, S, bM." Recomputing his offset from 25 Her shows his position is less than 1' too far south and exact in RA. UGC does not label UGC 10366 as NGC 6142 but the galaxy is correctly labeled in MCG, CGCG and RC3.

400/500mm - 17.5" (6/24/95): very faint, fairly small, elongated 2:1 NNW-SSE, broad weak concentration. A mag 15 star is just off the SW edge 55" from center. Located almost at midpoint of two mag 12/12.5 stars 5.6' N and 4.4' S. Two mag 14.5-15 between 2'-3' NW are collinear with the galaxy.

Notes by Steve Gottlieb