This collection consists primarily of incoming letters to Walter B. Roberts of New York about the Roberts Petroleum Torpedo Company and to a lesser degree one of its affiliated businesses, Houghton, Roberts, & Company. At the same time the Roberts Torpedo Company was founded, Walter and his brother Colonel E.A.L. Roberts also formed Houghton, Roberts, & Co. in Titusville with their brother-in-law, L.L. (Lucius Lycurgus) Houghton (1819-1905), the husband of Catharina Maria Roberts (1814-1869). A lumber yard and planing mill, Houghton, Roberts, & Co. produced oil barrels and oil tanks. Houghton sold his share and left the company a little over a year after its founding due to his contentious relationship with E.A.L.

Most of the letters to Walter are from E.A.L. Roberts with a significant amount from L.L. Houghton, both of whom were living in Titusville, Pa. Other correspondents include various affiliates of the Torpedo Company such as customers, clients, suppliers, investors and shareholders; and attorneys who represented the Roberts, especially Mason, Fenwick, & Lawrence, American and Foreign Patent Attorneys, D.C., in matters of the Roberts Torpedo patent and related lawsuits. Scattered throughout the collection are a few letters to E.A.L. Roberts and outgoing letters from Walter Roberts.

The letters, which begin with Colonel Robert's arrival in Titusville in January 1865, provide a significant amount of information about the experimentation with and development of his torpedoes, including the transition from gunpowder to nitroglycerin. They also document Roberts Torpedo Company and Houghton, Roberts, & Company's day-to-day operations and growth, as well as the challenges the brothers' enterprises faced; and provide some financial information about the companies. Enclosed with a few letters are receipt and expenditure reports for the Torpedo Company.

Other financial papers, primarily in the form of receipts, and legal papers of the two companies are also part of the collection. Included is the court transcript of a lawsuit involving E.A.L. Roberts and Professor Alexander Hamar, one of Roberts' main competitors in the Titusville area (November 1866). There are also some personal receipts and court papers relating to Walter B. and E.A.L. Roberts.