This letterbook covers the period June-October 1899. Most of the correspondence is by Walter S. Mallory, vice-president of the company. There is also correspondence by John F. Randolph, treasurer, and Francis R. Upton, sales agent for sand. The letters deal mainly with personnel matters, company financial obligations, briquettes, equipment, supplies, and sand orders. Some of the items relate to state taxes and the filing of reports with the state. A few letters pertain to cement. One letter concerns plans to mill gold ore at the Ortiz mine in New Mexico. The front cover is labeled "Letter Book of the New Jersey & Pennsylvania Concentrating Works From June 2, 1899 to October 23, 1899." The book contains 499 numbered pages and an index. Less than 10 percent of the book has been selected. Courtesy of Thomas Edison National Historical Park.