Tucked between advertisements for McCormick-Deering tractors in this student-run agricultural journal from the Ontario Agricultural College sits a piece of building science that most twenty-first century homeowners would consider revolutionary — and would pay a premium to install today.

HOUSE INSULATION A NEW IDEA. A house lined with Cork is warmer in winter and cooler in summer. Fuel bills are reduced fully 30 per cent. ARMSTRONG'S NONPAREIL CORKBOARD has kept the heat out of cold storage rooms for the past thirty years. It will prevent the heat escaping from your home in just the same manner. Why burn fuel and allow the heat to flow readily through your walls and roof?

The O.A.C. Review was the campus magazine of the Ontario Agricultural College at Guelph — a mix of student essays, farming advice, and advertisements aimed at Canadian farmers navigating the mechanization of agriculture. This particular February 1928 issue leaned heavily on the era's obsession with efficiency: tractors that saved labour, plows that saved time, and — remarkably — cork that saved fuel.

What's striking is the claim's specificity. Thirty percent fuel savings is not marketing puffery; it's within the range that modern building scientists cite for insulating a previously uninsulated wood-frame home. Armstrong's Nonpareil Corkboard was made from ground bark of the cork oak (Quercus suber), compressed with its own natural resins under heat — no synthetic binders. Its thermal conductivity is roughly 0.040 W/m·K, essentially identical to modern fiberglass batts and better than many spray foams.

Cork insulation dominated cold-storage construction from roughly 1890 to 1940. Then something odd happened: it vanished. Petroleum-derived alternatives — fiberglass in the 1940s, polystyrene in the 1950s, polyurethane foam in the 1960s — undercut it on price. The knowledge didn't disappear because it was wrong; it disappeared because oil was cheap.

Modern readers will recognize what happened next. As embodied carbon became a design constraint and off-gassing from foam insulation became a health concern, cork made a quiet return. Portuguese manufacturers like Amorim now sell expanded cork board (ICB) as a premium green building product, typically at three to five times the price of foam. It is:

• Carbon-negative — the cork oak sequesters CO₂ and regrows its bark every nine years without being felled
• Fire-resistant without flame retardants (it chars rather than melts)
• Rot-proof and pest-resistant due to natural suberin content
• Recyclable and biodegradable at end of life

The 1928 advertisement's throwaway line — "kept the heat out of cold storage rooms for the past thirty years" — is the key clue. The commercial refrigeration industry had already proven cork's durability by 1898. Homeowners were being offered a mature, field-tested technology, and then we forgot about it for nearly a century in favour of materials that require petrochemicals and cannot be composted.