In cases where, in one language, a particular term is applicable to several professions, industries, etc. while the foreign equivalent varies according to the industry, etc. in which it is used, the particular branch of industry is noted in parenthesis in accordance with the Explanations of Abbreviations and Signs given at the beginning of the book. This reference has, however, been omitted where there can be no doubt as to the industry, etc. covered by the term. Expressions which are preferred, or are used almost exclusively, in the United States, are marked (A). I would like to sincerely thank all the individuals, institutions, firms, etc. for their generous as- sistance in placing their excellent and valuable material at my disposal. Their ready co-operation has enabled me to include in this dictionary a large number of technical terms which have not, to my know- ledge, as yet appeared in any dictionary devoted to Engineering, Agriculture, Commerce, or Communi- cations. The number of those who, by making valuable original contributions available to me, have added to the contents of this new edition, is too large to permit of all their names being recorded here.