= Extremely rare. Both titles are listed by Worldcat, but no libraries listed at all holding the works. Both volumes contain the original tipped-in errata-leaf. The first volume contains a preface in English by Lorentz (also in Japanese translation). “The text-book of which a translation is here presented to the Japanese reader, is the outcome of the lectures on elementary physics which I have given for many years in the University of Leiden. It is intended to be mainly an introduction into the general ideas and methods of modern physics; these have a prominent place in it and I have trid to give a clear account of them, omitting many facts and experimental details which I considered to be of secondary importance.(…)” (preface). Hendrik Antoon Lorentz (1853 - 1928) was a Dutch physicist who shared the 1902 Nobel Prize in Physics with Pieter Zeeman for the discovery and theoretical explanation of the Zeeman effect. He also derived the transformation equations underpinning Albert Einstein’s special theory of relativity.. According to the biography published by the Nobel Foundation, "It may well be said that Lorentz was regarded by all theoretical physicists as the world's leading spirit, who completed what was left unfinished by his predecessors and prepared the ground for the fruitful reception of the new ideas based on the quantum theory." He received many other honours and distinctions.