In a message dated 97-02-10 15:37:38 EST, Henry Grunder wrote that:

<< two of the exhibit vitrines >> designed by an architect  for <<the lobby
of
 our new building >> are<< tall vertical cases with tungsten halogen
 lamps in the ceiling of the case (no light attic) >>.

Tungsten halogen lamps run very hot, and are very rich in the short-end UV
radiation.  They also have a nasty habit of exploding, especially if the bulb
itself has been handled and any skin residue remains on it.  As a
consequence, a glass filter is required.   Optivex filters from Bausch & Lomb
 are the only filters I know of that are available in the US for TH lamps.
 Information can be obtained from Bausch & Lomb, Thin Film Technology
Division, Marketing Department, 1400 North Goodman Street, Rochester, NY
14692, Phone: 716-338-6350; Fax: 716-338-6687.

I have a list of six distributors in the US and three in the UK and Europe
which I can post if anyone wants.

Wendy Claire Jessup
President and Conservator
Wendy Jessup and Associates, Inc.
210 Little Falls St., Suite 203
Falls Church, VA  22046
(703) 532-0788
(703) 532-1661 (fax)