Albert Marth discovered NGC 6688 = m 388 = Sf 35 = St II-24 on 3 Aug 1864 and noted "F, pS, R, bM." His position matches UGC 113245. Truman Safford found the galaxy on 6 Jun 1871 and noted "vmbM, 40" diam, nucl 12m". Finally, Édouard Stephan rediscovered the galaxy again on 25 Jul 1870 and measured an accurate micrometric position (using Esmiol's re-reduction). Stephan is listed as the discoverer in the GC Supplement (5926). Dreyer credited both Marth and Stephan in the NGC. The NGC position is nearly 5' too far north, though Bigourdan also measured an accurate position on 28 Jul 1886.

300/350mm - 13.1" (7/27/84): faint, small, low surface brightness, faint stellar nucleus. Located 30' ENE of STF 2362.

400/500mm - 17.5" (7/5/86): moderately large, diffuse, round, prominent small bright core, possible stellar nucleus. Pair with UGC 11325 8.0' S.

Notes by Steve Gottlieb