We're accustomed to finding interesting and unusual exhibitions at the Canadian Centre for Architecture.

A gallery entitled "An Endangered Species" brings home concepts of energy and its conservation for younger viewers. British illustrator Harriet Russell was invited to create a children's story to accompany the larger exhibit "1973: Sorry, Out of Gas."

She does a wonderful job, using pencil, ink, paint and silkscreening to produce whimsical images that make important points. Drawings painlessly introduce concepts of biofuels, geothermal energy and even the potential of waves.

Kids (and adults) will see the impact of lowering a thermostat six degrees. It'll be hard for a child to forget the idea of an underground home after seeing Russell's rendition of "mowing your roof."

WATERSHED YEAR

With "Sorry, Out of Gas" the center has taken a time three decades ago and made it fully relevant to the present day.

When living in North Carolina in 1973, I'd go out of my way to fill up at a Texaco station that offered gas at 29.9 cents a gallon. Why not? It let me avoid the inflationary 33.9 cents charged at most other places. Who knew that by 1979, gas at the pump would top a dollar a gallon, beginning an upward trend that continues to this moment?

At the time, I was busy enough in my studies not to have noticed any kind of crisis. But 1973 turns out to have been a watershed year. On Oct. 17 that year, oil-producing countries doubled the price per barrel of crude oil and decreased production by five percent, threatening an economy soaring for three decades largely on the assumption of infinite cheap energy supplies.

For the first time outside of war, Europe and America had to consider rationing and conservation measures. A new relationship had developed with the countries on whom oil supplies depended. In a sense, it marked the beginning of the politicization of oil.

SUN AND WIND

"Out of Gas" looks at the response of architecture and engineering to what now gets termed the first gas crisis.

Rooms throughout the exhibit analyze passive and active solar energy, wind power, recessed and underground homes and pioneering integrated systems. Large diagrams sketch out basic physical principles. Then a mix of photographs, news clippings, trade magazines, audiovisual presentations and artifacts help piece together the story.

Passive solar efforts largely involved the use of creative house siting, new materials and heavy heat-retaining units that provided greenhouse effects and allowed natural convection within the home. Inventions like those of insulated glass played a role. French development of the Trombe wall, using glass as a "trap" for masonry to absorb large amounts of heat for later distribution, marked another critical advance.

We listened to interviews with notable players in the movement.

In 1971, Albuquerque tinkerer Steve Baer built a home of 11 polygons that he called "zomes." Then he began Zomeworks, his still active business that developed and marketed inventions designed to maximize energy conservation. His use of easily accessed materials and simple plans encouraged a "do-it-yourself" ethic. My wife and I happened upon Zomeworks during the late 1970s. Our house still incorporates ideas we learned there.