During this fiftieth year of the Association's
existence we have had many an occasion to look
backward and appraise the foresight and courage
of those few men who, with a firm faith in the
future of d:strict heating, formed what has become
a sturdy, active, and progressive organization.
''''hile growt!l over those years has not been
spectacular, and it could not be in so specialized a
field, still, from the original handful, we now boast
some 559 members. Of course, being such a closely
knit organization, we boast several advantages. We
are the only source of information for all phases
of district heating. We are highly receptive to new
ideas and, being intimately associated, free interchange of ideas exists. Progress, on result of free
discussion, is evident in the changes which have
taken place over the past half century.
When the Association was conceived, boilers of
250 horse power were in use. Today, boilers of
1,000,000 pounds of steam per hour are not uncommon. During the extreme cold weather of 1909,
firing was simply a matter of generating enough
steam; coal was cheap, efficiencies were not of prime
importance, and the smoke could blow where it
would. Hand firing has been replaced by the automatic burning of coal, oil, or gas. Fuel is expensive. Efficient operation of boiler plants is a major
concern, and smoke control is a necessity. Herein
lies, probably, the greatest contribution of district
heating toward the welfare of large cities-efficient
use of our natural resources, and reduction of air
pollution.
The distribution mains of wrought iron pipe
with screwed joints, encased in wood-log insulation
have been replaced by modern welded steel encased
in cell concrete, plastic coatings, or other types of
low thermal loss insulation.
Modern office buildings use centrally generated
heat in ways and quantities which fifty years ago
would have seemed fantastic.
So much for the past fifty years, the historical
aspects of which are much more thoroughly presented in other parts of this magazine, and on to
the immediate future. The Spring meeting of the
Executive Board has recently been held. An outstanding technical program for the June Annual
Meeting has been completed. All fac~ts of the
industry have been treated. A worthwhile invest-
ment in time will be made by those who attend.
Our hard working committees promise an unusual
program of entertainment, and the ladies in par-
tiCLdar will have an interesting time. Everything is
set for Skytop. You cannot afford to miss it.
Next, we would like to call attention to this
magazine. As a special fiftieth anniversary issue it
will prove to be a keepsake. Its historical value is
embellished by the nature and abundance of excel-
lent articles.
To those who are advertising in its pages for
the first time we extend greetings. To those who
increased their advertising space we offer our con-
gratulations; and to those who are our regular
supporters we say, as to old friends, sincere thanks.
To all those who have aided in increasing our
membership we are extremely grateful. To those
who have labored over the past fifty years to make
our Association what it is today, we join all the
previous Presidents in commending your efforts.
If those of us who are privileged to examine
this issue of "District Heating" could look back on
our efforts from a point some fifty years hence, we
feel sure that our milestone would not pass un-
noticed. Undoubtedly progress, with its rapidly
accelerating pace, will have produced much more
than we now dream is possible. ''''hat the future
will unfold is, at best, a wild guess. From where
we now stand, central station power generation,
with an ever growing use of nuclear fuels, points
