This folder contains documents, primarily correspondence, relating to activities, equipment, and improvements at the Ogden works. Most of the letters are from Fred R. Andress and Cal Freid, superintendents, to Edison concerning daily activities and improvements at the Ogden works. Some letters concern the quality of briquettes and the development of a market for Edison's crushing technology, including its promotion by Frank C. Roberts, civil engineer of Philadelphia, and its adoption by the New Jersey Zinc Co. of Franklin, New Jersey. There are several items in Edison's hand relating to personnel matters, experiments, and lease negotiations. Included is a letter from Edison to Thomas Robins, Jr., president of the Robins Conveying Belt Co. in New York City, regarding the duplication of 36-inch rolls and Edison's intention "to design a whole line of milling machinery for sale." Other correspondents include geologist and mineralogist Henry C. Demming of Harrisburg, Pennsylvania, and metallurgist Robert H. Richards of the Massachusetts Institute of Technology. Some of the material may be partially or completely illegible due to light and faded ink and discolored paper. Approximately 30 percent of the documents have been selected. Courtesy of Thomas Edison National Historical Park.