How was William Lawrence Bragg awarded the Nobel Prize?

Name: William Lawrence Bragg. 
Country: United Kingdom.
Date of Birth: 31 March 1890.
Died: 1 July 1971.
Known as: X-ray diffraction, X-ray spectroscopy, X-ray microscopy, Bubble raft Bragg’s law, Bragg-Gray cavity theory, Bragg-Williams approximation.
Noble Prize Year: Nobel Prize for Physics in 1915 for their their services in the analysis of crystal structure by means of X-rays”, an important step in the development of X-ray crystallography.