That was the puzzle facing the State Library of NSW in 1982. The plate was one three giant glass plates created by Charles Bayliss for Bernard Holtermann in 1875.

It was part of a hoard of 3500 glass plate negatives discovered in a garden shed in Chatswood in 1951.

The find proved to be the most important photographic documentation of life during the Australian gold rush; a unique record of a generation experiencing an era of opportunity.

Almost 35 years ago, one of the giant glass negatives shattered. Attempts were made to repair the plate but no satisfactory solution was discovered.

It was boxed and put into storage. The question of how to recover it remained unanswered until now.