Handwritten letter on Amalgamated Mining Managers' Association of Australasia letterhead inviting students of the Ballarat School of Mines to attend the lecture on 'A Chapter in West Australian Geology' delivered by F.G. Johnson, F.G.S. at the Ballarat Mining Exchange. The artwork on this letterhead may have been executed by Henry James Hall.amalgamated mining managers' association of australasia, letterhead, j. sharpe, ballarat mining exchange, f.d. johnson, west australian geology, henry hall