Universal "Fireplug" Insulators

On April 12, 1910, Albert L. Stadermann of Terre Haute, Indiana received United States patent 954,596 for his "fireplug" shaped insulator.  Three designs of the fireplug were made: the 1001, the 1002, and the 1003, differing primarily in size although the 1003 has wider arms.

Below are pictures of known markings arranged in a preliminary numbering scheme.  Markings are usually recessed-embossed unless otherwise noted.
 
 

1001	1002	1003
	STYLE 1002A (Skirt embossing) PAT.APPL'D.FOR. (Skirt embossing) PAT.APPL'D FOR
	STYLE1002B (Skirt embossing) PAT.APPL'D.FOR (Front middle) UNIVERSAL (Back) PAT.APR.12.1910
	STYLE 1002C (Front) [Top block] UNIVERSAL [Bottom block] NO./1002 (Back) PAT.PEND.	STYLE 1003C (Front) [Top block] UNIVERSAL [Bottom block] NO./1003 (Back) PAT.PEND
	STYLE 1002D (Front) [Top block] UNIVERSAL [Bottom block] NO./1002 (Back) "PATENTED"/APR.12.1910	STYLE 1003D (Front) [Top block] UNIVERSAL [Bottom block] NO./1003 (Back) "PATENTED" / APR.12.1910
STYLE 1001E (Front)[Top block] UNIVERSAL / [Bottom block] 1001 (Back) [Top block] PAT.APR.12.10 / [Bottom block] 1001
STYLE 1001F (Front) [Top block] UNIVERSAL / [Bottom block] 1001 (Back) PATENTED/APR.12.1910
STYLE 1001G (Front) UNIVERSAL / NO.1001 (Back) PATENTED / APR.12.1910
		STYLE 1003H (Front) [Vertical marking]  UNIVERSAL/No.1003 (Back)[Possible triangle]/ PATENTED/APR.12.1910
		STYLE 1003I (Front) ? / 1003 (Back) PATENTED / APR.12.1910
		STYLE 1003J (Front) UNIVERSAL (Back) [Triangle with an M inside] / [Bottom block] 1003
	STYLE 1002K (Front) 1002 (Back) [Sideways M in a triangle]

Some colored 1001 Fireplugs have also been reported.  These were supposed to have been given out to long-term employees as service awards but I think there are a couple reasons to doubt this.  First, they were made by a slip casting process.  It seems that the company would be more likely to take one of the pieces straight off the line and color it rather than making a plaster mold, pouring a lower quality slip in it and firing it at a lower temperature than their normal kiln temperature.  Second, they are unmarked.  It seems unlikely that an item given to commemorate an event would be unmarked.  Third, I have seen miniature multiparts made using the same process and identical colors and even purchased these from the same person.  Below are some pictures of these.
Cobalt blue and green slip cast fireplugs.

Bottoms of the cobalt and green slip cast fireplugs.

Slip cast blue fireplug next to a regular production one.

This page created February 5, 2001