This was donated in 1915 by the Ballarat Masonic Lodges in appreciation of John Brittain's services to Freemasonry and to the Orion Lodge in particular. Freemasonry was very active in Ballarat from the gold rush era. The window was created and installed by the firm of W.J. Robson & Sons, which provided most of the Observatory's windows. The firm, which has served the Observatory and Ballarat for nearly 90 years, is still in operation in Main St. Ballarat, under the management of fourth- generation Robson glass craftsmen.