London: Harrison & Sons, 1913. 1st Edition. FIRST EDITION OF THE BRAGG FORMULATION OF X-RAY DIFFRACTION, A FUNDAMENTAL PAPER IN THE CONCEPTION OF THE NEW SCIENCE OF X-RAY CRYSTALLOGRAPHY LEADING, IN 1915, TO THE 1st NOBEL PRIZE AWARDED JOINTLY TO FATHER & SON. “Thanks to the methods the Braggs devised for investigating crystal structures, an entirely new world has been opened and has already in part been explored with marvelous exactitude. The significance of these methods and of the results attained by their means cannot as yet be gauged in its entirety however imposing its dimensions already appear to be. In consideration of the great importance that these methods possess for research in the realm of physics, the 1915 Nobel Prize in Physics is awarded to both William H. Bragg and his son William L. Bragg in recognition of their services in promoting the investigation of crystal structures by means of X-rays” (Nobel Prize Committee).
In 1913-1914 and inclusive of this work, Bragg and his son Lawrence “founded a new branch of science of the greatest importance and significance, the analysis of crystal structure by means of X-rays” (NPC). “Apart from specifying general symmetry relations, before June 1912 it had not been possible to give the actual arrangement of the constituent atoms of any crystal. . .. By the end of 1913, the Braggs had reduced the problem of crystal structure analysis to a standard procedure” (DSB, II, 399).
“Von Laue’s epoch-making discovery of the diffraction of X-rays in crystals, on the one hand established wave motion as the essential quality of those rays and, on the other, afforded experimental proof of the existence of molecular gratings in the crystals. The problem, however, of calculating the crystal structures from von Laue’s formulae was an exceedingly complicated one in as much as not only the space lattices but also the wavelengths and the intensity-distribution over the various wavelengths in the spectra of the X-rays were unknown quantities.
“It was consequently a discovery of epoch-making significance when W.L. Bragg found that the phenomenon could be treated mathematically as a reflection by the successive parallel planes that may be placed so as to pass through the lattice points, and that in this way the ratio between the wavelengths and the distances of the said planes from each other can be calculated by a simple formula from the angle of reflection” (NPC) “The Braggs discovered what are now called “Bragg peaks” (intense peaks of incident radiation) when crystals are bombarded by X-rays at particular angles and intensity. [The formula they discovered] for the occurrence of these peaks allowed them to explore the sizes and shapes of crystals through what is now called ‘Bragg diffraction’ (X-ray diffraction analysis using the formula for Bragg peaks)” (History of Physics: The Wenner Collection). “It was only by means of that simplification of the mathematical method that it became possible to attack the problem of the crystal structures” (NPC). Printing and the Mind of Man 406. Norman 312 & 313.
ALSO: We separately offer a 1934 Nature supplement on the Bragg’s liquid crystals telling “for the first time a coherent story has been made of the optical principles of liquid crystals by which their characteristic behavior is exhibited”. Item #1110
CONDITION: 4to. vi, 604, xxviii. Plates. Institutional copy, gilt-lettered; ghosting on the spine leather from (early?) removal of a label. Professionally reinforced and very solid. 1913 bookplate of University College of Wales and 3 small circular interior stamps. Save for some spotting to the endpapers, clean and bright throughout. Good+.