N. R. "Woody" Woodward is the author of The Glass Insulator in America, 1988 Report and developed the Consolidated Design Numbers identification system for glass insulators. 

Questions for this month's column were submitted by Dan Kelly of Smithton, Illinois

I was walking along Burlington Northern tracks a few years back in Missouri. From this line I had found several CD 151's and some choice CD 145's. One CD 151 found on this line strikes me as a little unusual. It is embossed H. G. CO. on the front and PETTICOAT on the back. What seems unusual about it is that under H.G.CO. there appears to be the 1893 Patent Date partially blocked out. This insulator has a smooth base.

Was this insulator made for a customer that specified smooth based insulators? Something else strange is that this appears to be older than the drip pointed counterpart -- embossing spread and semi faint, glass cruder than later models. Has anyone seen other H.G.CO. CD's with smooth bases and a the 1893 blot out?

The catalog listings for CD 151 in my files cover the period 1901 to 1918. I've found nothing to indicate what year the style was introduced; but it appears they were made at both Covington and Muncie. Although they never gained the general acceptance of the "beehive" style, they were in service in considerable numbers in all parts of the U.S.

The base rims come in three variations: drips on both skirts; drips on outer skirt only; and smooth base. In my personal experience, the ones with drips on outer skirt only are less common than either of the others. I've found hundreds of the smooth base ones in places. 

Since it was possible to use various combinations of mold cheeks and base rims, it is quite understandable that they removed the drip point patent from some molds when preparing to run smooth base. The very obvious partially-removed marking that you have found may be quite rare though. 

Hemingray apparently supplied insulators with drip points following the 1893 patent unless the customer specified otherwise. However, some styles, such as the CD 145 for Western Union and CD 121 Am. Tel. & Tel. Co. were made entirely with smooth base; and some other styles were probably stocked both ways.