This is a realy nice repaird example of this rare CD. Top skirt front embossed: LOCKE PATENTS APR,29, 1902 JUNE 7, 1898 NOV,2,1896 SEPT.28 1897 DEC,15 1896 APR,30 1891 back of top embossed : No 25 Base skirt embossed: LOCKE'S PAT'S DEC 15-96 JUNE 7-98 The main platter was split in four quarters and the base was in four big parts . With an 11" diameter top This is the largest early historic glass insulator ever used in North America and the only American cemented all glass multipart known to have been used on this continent. It was catalouged for max 50,000 Volt service ..... Their was only one production run of these in late 1903. Soon after being put into service in Colorado near Pueblo, many began to crack and fail from lightning flashover and cement expansion . The design was a total engineering failure. All were removed and replaced around 1922. Note the large quarter sized flat air bubble in the top skirt! Many of these were found in the late 1960's and a few have surfaced in more recent years .