Here is a medium Purple color glass CD 162 "signal" style insulator with sharp drip points, which were commonly used along railway signal telegraph lines, city fire alarm and lighting circuits, and early telephone lines. I purchased this one from Mr. Norman LaJoie about 12 years ago. The older price guide said $600-700 for Lilac or Purple, but this is not a Mint example (though it is quite near.) It has 4 missing drips just beneath "PATENT", a pinky nail size shallow flake off the underside of the upper wire ridge, and a skirt bruise chipped inside half of 3 drips beneath "PETTICOAT".

[070] crisply embossed "H.G. CO. / PATENT MAY 2 1893" across the front skirt, and "PETTICOAT" on the rear.

See next pic for price...