This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced

In 1901 the National Bureau of Standards (NBS) was founded to provide standard weights and measures and to be the national physical laboratory for the United St

Excerpt from Photoelectric Spectrophotometry by the Null Method Another source of trouble in most deflection methods has been the difficulty of eliminating the