[The following note describes a series of company records and has no images attached to it. To view the images in the records described here, use the "Which Series Notes?" button to enter the Series Notes or use the "Next Text" button to move to the first item in the series.]

The New York Concentrating Works (NYCW) was incorporated on April 28, 1891. On May 4, the first meeting of its board of trustees adopted the company's by-laws and elected the following officers: Edison, president; Samuel Insull, vice president; William S. Perry, treasurer; Thomas Butler, secretary; and Charles Batchelor, general manager. Insull resigned as trustee and vice president in October 1892 and was succeeded by Alfred O. Tate as trustee and Charles Batchelor as vice president.

One of several companies organized to exploit Edison's ore milling patents and mining property leases, the NYCW's objectives included the mining, processing, and sale of iron and other metallic ore products, as well as the development and sale or licensing of related technologies. The company acquired Edison's leases in Putnam and Rockland counties in New York, formed the Westchester and Putnam Railroad Co., undertook land surveys, and collected assays on samples. However, no milling plant was ever constructed. The NYCW became inactive after 1896 and gradually sold its property. In 1906 Edison had limestone samples from the remaining property analyzed for use in his Portland cement, but he found the magnesium content too high for his purposes. In 1924 the remaining land on Dunderberg Mountain was sold to the Palisades Interstate Park Commission. The NYCW was officially dissolved on April 2, 1924.

The records cover the period 1885-1925, but most of the material dates from 1891-1896. The documents consist mainly of financial materials, but also included are correspondence, annual reports, agreements, indentures, maps, mineral analyses, minutes, and proxies. A finding aid is available at the Edison National Historical Park.

The following categories of documents have been selected: letters by Edison or bearing Edison marginalia; other documents reflecting Edison's direct involvement in company matters; selections from the company's minute book, including the certificate of incorporation, by-laws, and minutes from trustees' and stockholders' meetings; annual reports. The company's ledger and journal have also been selected.

The following categories of documents have not been selected: capital calls, meeting announcements, stock certificates, and proxies; routine financial documents such as accounts payable, canceled checks, journal vouchers, payroll accounts, tax receipts, and trial balances. In addition, routine indentures, agreements, and routine property documents have not been selected. These include: indentures and agreements between Edison and the Philadelphia and Reading Coal and Iron Co. (1890); an agreement between the NYCW and the Reading Iron Co. (1890); the assignment of Edison's leases to the NYCW (1891); indentures witnessed by Edison (1906) and by Walter S. Mallory, president of the Westchester and Putnam Railroad Co. (1915); and abstracts of title relating to land leases in Putnam County (1915).

Courtesy of Thomas Edison National Historical Park.