This letterbook covers the period March 1889-May 1890. Most of the correspondence is by Thomas Butler, secretary of the company; Harry M. Livor, general manager; and William S. Perry, treasurer. There are also some letters by Samuel Insull, who was treasurer prior to January 8, 1890. Much of the correspondence deals with company financial obligations, stock transactions, stockholders' meetings, and personnel matters. Many of the letters concern the operation of the concentrating mill at Bechtelsville, Pennsylvania. Included is correspondence dealing with the supply of ore to the mill and with the disposition of machinery and other materials upon its closing. The front cover is labeled "The N.J. & Pa. Concentrating Works Letter Book." The book contains 895 numbered pages and an index. Pages 873-895 are blank. Less than 5 percent of the book has been selected.