The purpose of this project was to survey the National Bureau of Standards library holdings of pre-1900 works on metrology and from these, to assemble a special collection of historically important documents. The 265 imprints selected for the collection are listed in this report. Each entry includes the main author, title, imprint, and collation data. The collection is important historically beacuse the presence of many books are basic to the origin, development, and adoption of the international system of weights and measures both in the United States and abroad, and because of the comprehensiveness of the collection. (Author/DS)