Here is a pair of Brookfield Baby Signals I recently acquired from an online vendor.
These insulators got the nickname "Baby" because they are the smallest of the signal style shape. These two pieces produced sometime before 1922 stand 3.125" inches tall and both have an outer diameter of 2.875" inches. Of the many glass houses that made the baby signal I now have examples from Brookfield, Hemingray and the California Glass Insulator Company.
Embossing- front skirt: BROOKFIELD
rear skirt: NEW YORK
Embossing: No 32 B
I took advantage of the clear skies and set up in the back yard using the late afternoon sun to illuminate the glass. Although I was hurrying due to the temperature of 25 degrees and a bitter cold breeze I think the pictures turned out fairly well. An interesting effect is the shadow which adds a little depth to the images.
What looks like a chip in the glass at the base of the No 32 B insulator is actually a smooth underpour. There was not enough molten glass to fill the mold at this particular area so the glass settled and dried with a smooth radius. A small flaw like this would pass quality control inspection as it would not hinder the insulator's ability to do it's job.
Another feature in the photographs are the serpentine "straw marks" or shallow grooves visible on the dome above the shoulder on each of the insulators. I don't know of the cause of this phenomenon but my guess would be that the curvy channels were carved out by escaping gasses while the glass still thousands of degrees was forced under pressure to take on the shape of the mold. Details like this add uniqueness and character to these colorful pieces of telecom history .