The opening of Reid's Lightweight Aggregate Pty Ltd ( a subsidiary of Reid's Quarries Ltd) in Greensborough, circa 1960. Explains the method of manufacture and uses of shalite in building industry. Reid's later became Albion Reid before being taken over by Boral. The shalite quarry, now closed, was on the site now called Blue Lake in Yellow Gum Park, Plenty.7 photocopied pages, text and colour and black nd white illustrations.reids quarries, shalite, aggregate, yellow gum park, plenty