The Australian War Memorial Collection. Test site
THIS OPTICAL FLAT WHICH HAS BEEN MADE TO AN ACCURACY OF ONE MILLIONTH OF AN INCH IS USED TO TEST THE SURFACES OF PRISMS AND LENSES. (NEGATIVE BY E.L. CRANSTONE).
MT. STROMLO, MAKING OF LENSES FOR MILITARY INSTRUMENTS: AFTER FINAL POLISHING LENS IS TESTED WITH SODIUM MONOCHROMATIC LIGHT. THE LENSES MUST CONFORM TO AN ACCURACY OF ONE TWO MILLIONTH OF AN INCH OVE
WHEN THE GLASS HAS FUSED INTO A SOLID MASS IT IS SLOWLY COOLED. IT IS NOW TESTED FOR THE ABSENCE OF STRAIN. HAVING PASSED THE RIGID TEST IT CAN NOW BE MADE INTO LENSES OR PRISMS. (NEGATIVE BY E.L. CRA
DATE AND LOCATION UNKNOWN. OPTICAL GLASS BEING TESTED FOR THE ABSENCE OF STRAIN. AFTER PASSING THIS RIGID TEST IT IS MADE INTO LENSES AND PRISMS FOR SERVICE OPTICAL INSTRUMENTS.
MT. STROMLO, MAKING OF LENSES FOR MILITARY INSTRUMENTS: OWING TO DIFFICULTY IN OBTAINING SUFFICIENT OPTICAL GLASS HERE, SILVERED PLANES ARE USED INSTEAD OF USUAL PRISM - JACK CRISP HERE GRINDS AN OPTI
MT. STROMLO, MAKING OF LENSES FOR MILITARY INSTRUMENTS: EXPERIMENTAL WORK IS ALSO BEING CARRIED OUT WITH PRISMS, ANTICIPATING PRODUCTION OF OPTICAL GLASS IN AUST, A PROJECT WHICH IS WELL ON ITS WAY. H
THESE PRISMS HAVE ALL BEEN MADE FROM THIS FUSED GLASS, AND ARE IN USE IN INSTRUMENTS DESIGNED AT THE UNIVERSITY. (NEGATIVE BY E.L. CRANSTONE).
