This is a CD 158 Boston Bottle Works in medium aqua blue in the narrow wire groove variety. It is four segment and embossed "Boston Bottle Works - Patent Applied For -" around the inner skirt. It was found on the Central of Georgia Railway line near Box Springs, GA. I found six or seven of the narrow groove style Boston's on the line between Fort Valley and Columbus, GA. I kept this one as it was perfect mint. It has an interesting story as it was the only Boston I found on the ground. This was a section where the line moved to the South side of the tracks. I was walking through a section of pine woods and came up on track. The track had been recently regraded as it was much higher than the rest of the ground. This insulator was found on top of the fresh ground on the regraded North side of the track. I conclude that the original line must have been on the North side of the track. Also, this CD 158 did not have a pin and was fairly clean - not much black soot. All the GA Boston's that I found on the lines were all on "threaded" oak pins and all had very heavy soot deposits on the glass. This suggest that the CD 158 Boston's - at least on the line from Fort Valley to Columbus, GA - were only used for a limited amount of time. Another interesting note - Bill Rosato, Claude Wambold, Jim Frustieri, and I took a collecting trip down to GA in order to hunt insulator in the mid-1990's - when you get old you forget exact dates. We mostly hunted the line between Columbus and Fort Valley, GA. The older line was gone, but we did find a large number of CD 158 Boston Bottle and threadless glass shards along this line where the line was trenched and put underground. Clearly, there was buried glass along the line.