Charles Messier discovered M18 = NGC 6613 = h2007 on 3 Jun 1764 and recorded "A cluster of small stars, a little below above nebula, No. 17, surrounded by slight nebulosity, this cluster is less obvious than the preceding, No. 16: with an ordinary telescope of 3.5-foot [FL], this cluster appears like a nebula; but with a good telescope one sees nothing but stars. (diam. 5'). On 22 Jun 1784 (sweep 231), WH logged it as "a cl of coarsely scattered L stars, not rich." On 16 Jul 1830, JH called it "A poor and coarse cluster. Contains about a dozen stars 10m and 15 or 20 more 12 .. 15m."

400/500mm - 17.5" (8/1/92): at 100x, bright, scattered, includes three mag 9 stars and 10 mag 11 stars. The bright stars form a "V" asterism with the vertex to the NNE. Includes a few wide double stars. At 220x, 40 stars are visible in a 7' diameter, scattered but distinctive. The bright group of 15 stars forming the "V" asterism is surrounded by a dark circular void. The rest of the cluster is to the south and west of the "V". Only a few faint stars are involved and the cluster appears fully resolved.

Notes by Steve Gottlieb