The writer is not clear as to the time of the first use of porcelain as an insulator in lamp bases. Perhaps a viewer of this web site will be able to clarify this confusion. The writer has long believed that widespread use of porcelain occurred about 1900. This date was, perhaps, implied in the information on page 188 of the book by Howell and Schroeder. This was also implied by Arthur Bright in his book, on page 116. However, there is considerable evidence that porcelain was used before 1900. It is now believed that this writer simply misinterpreted what Howell and Schroeder said in their book. On page 189 of H & S's book it is said that porcelain was used in the year 1900. This was mentioned simply to say that the following year, 1901, black glass was used. H & S didn't say that porcelain was introduced in 1900. Indeed, in Schroeder's book, on page 58, bases are shown in which porcelain was used in 1892. In addition, there is an article in the The Electrical Engineer, Vol XVIII, No 341, Nov 14, 1894, in which images of ten common bases of that day are shown. Of those ten base types the Westinghouse or Sawyer-Man, the Westinghouse Stopper, the United States and the Edison bases appear to have porcelain insulation. Thus, it appears porcelain was used to some extent in the year 1892. Hopefully the year of first introduction will be revealed by a collector.