Sapphireblue.com Presents: Adventures in Dangerous Art (Back to the Future)

The National Park Service has a division called Heritage Preservation Services which "helps our nation's citizens and communities identify, evaluate, protect and preserve historic properties for future generations of Americans." They put out a series of publications called Preservation Tech Notes "intended for practitioners in the preservation field, including architects, contractors, and maintenance personnel, as well as for owners and developers seeking the preservation tax investment credit for rehabilitation." A few of these are online. One is entitled "Historic Glass: Repair and Reproduction of Prismatic Glass Transoms."

Introduced in the 1890s, prismatic glass transoms were a popular and practical means of directing daylight into building interiors. With origins in sidewalk vault lights and glass panels used on ship decks, prismatic tiles had ridges or other raised patterns on their inside surface that refracted sunlight toward the rear of a building. The pressed tiles were usually joined together with zinc or lead in a process similar to that used to create stained glass windows. An alternative, less common approach was to bond the tiles to copper strips during immersion in an electrolytic bath, a process known as electroglazing. At the peak of popularity, over a dozen manufacturers offered varying tile patterns - each "scientifically designed" to increase natural light levels and thereby reduce reliance upon light wells and artificial light sources. Prismatic glass tiles were used both in new construction and to update existing storefronts, until changing tastes and the dominance of electricity led to their functional obsolescence by the 1930s.

Really smart stuff. "The dominance of electricity" shows no signs of abating, but the world has come a long way in increased environmental consciousness since the 1930s, and I wonder if someone, somewhere, hasn't had the thought that prismatic transoms and windows are more energy-efficient than standard electric lighting and a hell of a lot lower-maintenance than solar-powered lighting of any kind.

Posted by Michelle on November 03, 2002 09:19 PM


I'm learning the art (or is it a craft?) of stained glass. At this weblog, I record progress, note useful links, and document flesh wounds. Links The Art League Where I took a lead class and a 3D construction class. Weisser Glass Studio Where I buy supplies, and where I took a foil class. Virginia Stained Glass Co. Where I buy supplies if I happen to be in Springfield and if they happen to have what I want. Warner-Crivellaro Great prices on supplies, a lively and helpful Glass Chat message board, and excellent Technical Tips on stained glass tools and techniques. Glass Galleries Links List A list of Glass Chat users who've uploaded photos of their work. The StoreFinder: Stained Glass Store Front Lots of articles. ArtGlassArt.com Tutorials Even more articles. Particularly recommended: "Anatomy of a design" and "Wood frames." rec.crafts.glass Courtesy of Google Groups. Nancy's Beginner Tips and Tricks Scoring, breaking, soldering, finishing, and more. Splinter Removal Tips Crucial. Syndicate this site Someone out there is using XML for something... right? Movable Type Powered by. Archives By Date November 2006 October 2006 May 2006 June 2004 October 2003 September 2003 August 2003 June 2003 May 2003 April 2003 March 2003 February 2003 January 2003 December 2002 November 2002 October 2002 September 2002 By Project Beaded Unity Candle Crocus Panel Dogwood Windows Green Tiered Lamp Lilypads/Lotus Panel Transoms Xmas Ornament		« Breaking the Habit \| Main \| The Wright Stuff » November 03, 2002: Back to the Future The National Park Service has a division called Heritage Preservation Services which "helps our nation's citizens and communities identify, evaluate, protect and preserve historic properties for future generations of Americans." They put out a series of publications called Preservation Tech Notes "intended for practitioners in the preservation field, including architects, contractors, and maintenance personnel, as well as for owners and developers seeking the preservation tax investment credit for rehabilitation." A few of these are online. One is entitled "Historic Glass: Repair and Reproduction of Prismatic Glass Transoms." Introduced in the 1890s, prismatic glass transoms were a popular and practical means of directing daylight into building interiors. With origins in sidewalk vault lights and glass panels used on ship decks, prismatic tiles had ridges or other raised patterns on their inside surface that refracted sunlight toward the rear of a building. The pressed tiles were usually joined together with zinc or lead in a process similar to that used to create stained glass windows. An alternative, less common approach was to bond the tiles to copper strips during immersion in an electrolytic bath, a process known as electroglazing. At the peak of popularity, over a dozen manufacturers offered varying tile patterns - each "scientifically designed" to increase natural light levels and thereby reduce reliance upon light wells and artificial light sources. Prismatic glass tiles were used both in new construction and to update existing storefronts, until changing tastes and the dominance of electricity led to their functional obsolescence by the 1930s. Really smart stuff. "The dominance of electricity" shows no signs of abating, but the world has come a long way in increased environmental consciousness since the 1930s, and I wonder if someone, somewhere, hasn't had the thought that prismatic transoms and windows are more energy-efficient than standard electric lighting and a hell of a lot lower-maintenance than solar-powered lighting of any kind. Posted by Michelle on November 03, 2002 09:19 PM Comments Do you know of anyone interested in buying the prismatic glass tiles used in the transoms? Posted by: K. A. Gilmore on November 6, 2003 06:29 PM Comments are closed. Contact me via the email address at the bottom of the blog pages.
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