I found this on the company bulletin board server and thought the
preservationists might be interested.  The gentleman who posted this is an
avid sky watcher, hence his desire to reduce undesirable light.

- Pam
---------------------- Forwarded by Pam Blythe on 07/28/98 08:43 AM
---------------------------

From:     Tim Poulsen
Date:     07/27/98 11:08:52 AM
Subject:  Outdoor lighting good practices

Folks,

I have left an information sheet titled "Good Neighbor Outdoor Lighting"
tacked to the bulletin board in the west staff lounge. This sheet describes
some of the problems that arise from improper and insensitive outdoor
lighting.

For example, did you know that each year in the US over $100,000,000 (one
hundred million dollars) is wasted by the inefficiencies of mercury-vapor
lights alone! These are one of the most common outdoor lights and are
typically used as all-night security lights. They are incredibly
inefficient. Most of the light they produce goes sideways or up where it
does no good. They produce harsh glare and shadows that can actually reduce
security and safety. The glare blinds drivers and pedestrians; the harsh
shadows give miscreants nice places to hide, safely out of view. These
lights cost more to operate each year than they cost to buy. Worse yet,
they produce less and less light over time but use the same energy to do
so. After about five years they produce about 1/2 their original light
output yet use the same amount of electricity. In fact, mercury vapor
lights never blow out, they just get dimmer and dimmer.

Other estimates put the total waste produced by inefficient lighting from
all lighting designs at around 1 Billion dollars per year in the US! That
means higher taxes and utility bills for us all.

The info sheet describes good light designs. Good light designs might cost
a bit more up front. However, they provide the same or better security and
safety with less light output and therefore cost a lot less over time to
operate. I encourage you to follow good lighting practices and encourage
friends, family, and your local government to do the same.

If the sheets come up missing or you would like your own copy, it is
available on the web at http://www.skypub.com/lpnotes/gnol.html The
International Darksky Association is a lobbying and education group devoted
to eliminating poor and wasteful outdoor lighting practices. Their web site
is at http://www.darksky.org (they have lots of additional information
about light pollution on their site).

Thanks,
Tim