In the collection are one hundred and fifteen letters from Robert Stephenson to Illingworth mostly written from Mariquita, Colombia, between September 1824 and November 1828 on the management of mining affairs in Colombia, mining laws in general and how they could be adapted to conditions in Colombia. Fourteen letters were written by Stephenson to Illingworth between 1848 and 1858 when both men were living in England which deal with news of their native country. Among the papers are also fifteen diaries of Illingworth, kept between 1816 and 1842, on the location of mines, including small sketches and positions of mines, reports, an informative and vivid description of a journey on land and aboard the Bongo boats giving a clear idea of the life, people, geographical position, and conditions in Colombia in 1829, a list of the staff and miners with comments on their work and character, supplies required, calculations and cost of mines, detailed mining information on selection and treatment of ores, and an account of a journey to the United States. Another important item is a thirty-nine-page report to the Board of Directors of the Colombian Mining Association. Of interest is also a detailed and descriptive itinerary of a journey from Mariquita to Arma in August 1826 written by Ed Walker.

A memoir, reports, observations, and several letters on mining written in French between 1823 and 1836 from Jean Baptiste Boussingault, the French agricultural chemist, who became famous for his discoveries on the absorption of nitrogen by plants, add to the value of the collection. Boussingault went to Colombia about 1813 as a mining engineer for the Colombian Mining company. During the insurrection of the Spanish colonies he was attached to the staff of Simon Bolivar and traveled widely in the northern parts of the continent. Included are also two letters, August 15, 1870, and March 20, 1872, discussing the Franco-Prussian war.

Four letters from Simon Bolivar and one from his nephew and secretary, Fernando Bolivar, in Spanish are of interest to the scholar because of their content. The first two letters to Jose Fernandez Madrid dated September 27, 1827, refer to finances in connection with his mines in Venezuela with special reference to a bill of exchange for twenty thousand pesos made out to Joseph Lancaster, the noted British educator, to help him further the cause of primary education in Caracas by importing the benefits of his system. The third letter was writen to the naval officer Juan Illingworth. In this letter of June 9, 1830, the Liberator expresses his affection and trust in Illingworth and asks him to turn over to Manuela Saenz the money coming from the impending sale of a mule. In the fourth letter which was written to Richard Stonhewer Illingworth dated August 2, 1830, Bolivar profusely thanks Illingworth for fulfilling a mission for him and adds that he is thinking of going to England at once to show how deplorable conditions are in Colombia and how much damage ships leaving the harbor of Cartagena have suffered. A brief note was appended to the letter from Bolivar's nephew, Fernando. On January 9, 1831, Fernando Bolivar wrote to Juan Illingworth thanking him for the valuable services rendered to his uncle and discussing the circumstances surrounding the Liberator's death. Something of a more personal nature in this collection is a lock of Bolivar's hair which was cut after his death and was given to Juan Illingworth on January 10, 1831, at Guaduas.

Six documents and copies of six letters in Spanish on the Panama Canal, 1825-1829, concerned with the mines and the Isthmus of Panama, add to the value of the collection.

Included are also forty-two water color drawings, one pencil sketch, and one pen and ink sketch by Stonhewer E. Illingworth, son of Richard Stonhewer Illingworth, 1797-1884; pen and ink drawing and description of a plan for the use of a distilling furnace; certificates of stock in the New Granada Mining company; and a printed account of the St. John del Rey Mining Co.

Some of the material is in an oversize folder.

Among the correspondents in the collection are William Pitt Adams, Juan de Dios Aranzazu, Charles G. Austin, Antoine Cesar Becquerel, William Matthews Blackford, J.H. Bodmer, Fernando Bolivar, Simon Bolivar, Jean Baptiste Boussingault, Patrick Campbell, John Chapman, Michael Adrian Coppinger, Juan Garcia del Rio, Thomas Longridge Gooch, Edward Hurry, Manuel Jose Hurtado, Jorge Illoyo, John Cordy Jeaffreson, Sir John Kirkland, F. Marcos, Jose Vicente Martinez, Santos Michelena, Jose Maria Obando, Thomas Parker, William Parker, Edward P. Penny, Lino de Pombo, John Deston Powles, Jose Manuel Restrepo, Vicente Rocafuerte, J.E. Sanderson, James Smyth, Robert Stephenson, Jonas Stowell, Rafael Urdaneta, Jose Felix Valdivieso, Fred J. Warre.

Note on Indexing Terms - "Art": Of interest are Illingworth's diaries which include small sketches and positions of mines in Colombia. Also included are forty-two watercolor drawings, one pencil sketch, and one pen and ink sketch by Stonhewer E. Illingworth, son of Richard Illingworth; and a pen and ink drawing and description of a plan for the use of a distilling furnace.