Folder: S.F. Fire Department-Truck 6.
On back: "CAPTION. STOUT FIREMEN'S MUSCLE SLAMS a ladder into sample sheet of tempered glass in a demonstration test conducted recently for officials of the San Francisco Fire Department. Purpose of the test was to show the merits of tempered glass as a solution to venting outside windows in curtain wall structures for the most rapid release of smoke. When broken, the glass disintegrates into innumerable small blunt-edged fragments giving an immediate opening with a minimum risk of flying glass injury to firemen. The Herculite tempered glass tested is the type to be installed in Bank of America's new $13 million Service Center to be built soon at Market and Van Ness Avenues by Swinerton & Walberg Co. Weilding the ladder in lusty fashion are Fireman Jim Burke (left) and Al Harris from Truck 6."
