The investigation of the x-ray appears early on to have been a priority research topic at the University of Melbourne’s School of Physics. This interest was sparked by the appointment in 1889 of Professor T.R. Lyle. Lyle, who was head of the school until 1915, is thought to have been the first person in Australia to have taken an x-ray photograph. A copy of this photograph can be found in the School of Physics Archive. For this particular experiment Lyle actually made his own x-ray tube. His successor, Professor Laby, continued to work with x-rays. During the 1920s Laby worked on the x-ray spectra of atoms and in 1930 he co-published with Dr. C.E. Eddy, Quantitative Analysis by X-Ray Spectroscopy. Also with Eddy, Laby produced the landmark paper Sensitivity of Atomic Analysis by X-rays. Laby went on to have an x-ray spectrograph of his own design manufactured by Adam Hilger Ltd. (see cat. No. 38). School of Physics, the University of Melbourne Cat. No. 22. Jacqueline Eager Student Projects Placement, Cultural Collections 2005 In 1913 Coolidge overcame the limitation of the narrow operating range of the gas X-ray tubes with the invention of the vacuum X-ray tube. A filament heated by an electric current directly releases electrons by thermionic emission. In thermionic emission, electrons are emitted from a metal surface directly by the application of an electric current to heat a wire filament. The electrons accelerate to the anode and produce X-rays. The anode has associated cooling fins due to the high temperatures attained by the release of kinetic energy by the electrons on colliding with the anode. Internal Glass sleeve: “A941/L2593/2821”