This letterbook covers the period November 1892-April 1893. Most of the correspondence is by Thomas Butler, secretary of the company; William S. Perry, treasurer; John P. Walsh, sales agent for sand; and Edwin I. Olmsted, clerk. The letters deal mainly with personnel matters, company financial obligations, stock transactions, equipment, supplies, and sand orders. Some of the letters pertain to Edison's experiments at the Ogden works, fire precautions at the mill, and the ore milling processes of other companies. There are also minutes of a directors' meeting. The spine is stamped "Letters" and is marked "C." The book contains 699 numbered pages and an index. Less than 5 percent of the book has been selected.