sioned by the Minister of War as astronomer to determine latitudes and azimuths and make geodetic observations in the triangulation of the Belgian coast. He performed this work with great credit to himself and advantage to the service till 1857, when, the appropriations failing, he was dismissed. About this time (1857) he published his History of the Soil of Europe—the most important work he produced prior to crossing the Atlantic. It was accompanied by a map which deserves mention as embodying the first attempt that was made, with a satisfactory degree of success, to represent the relief by curves and by successively deeper tints of shading. Berghaus had previously attempted a map with relief curves, but it left much room for improvement.
After his dismissal from the work of triangulation, Houzeau proceeded to carry out a desire which he had cherished for many years to visit the United States, where he expected to study a society and customs different from those with which he was acquainted. He embarked from Liverpool on an emigrant sailing vessel, on the 11th of September, and reached New Orleans after a voyage of seven weeks, much of the time marked by hard storms. He expected to remain in America a few months. His residence actually lasted twenty years. Full accounts of his experiences and observations during the first ten of those years are given in his twenty-four communications to the Revue trimestrielle. The letters, treating of many questions, constitute, for the time in which they were written, a complete, vivid, and animated picture of the manners and institutions, and the social, political, and intellectual conditions of the districts in which he abode. The question in which he appears to have been most deeply interested was that of the abolition of slavery. After staying at New Orleans long enough to get a passable practical knowledge of the English language, he went to San Antonio, Texas, where he was engaged in surveying for irrigating canals; then made a six weeks' excursion to the Rio Grande, during which he found abundant opportunities to carry on studies of the winds; he was interested in observations of Donati's brilliant comet and speculations as to its identity with the comets of 1264 and 1556; and was commissioned to make surveys in western Texas for the settlement of some Spanish land titles which had been acquired by a company. He describes his life here as that of the regular frontiersman.
When the civil war broke out, Houzeau was in southern Texas, about to start on a geological excursion to the borders of the Indian country. The trip occupied six weeks, and, on his return, he seems to have got himself into some trouble by assisting in the escape of a fugitive slave. After resting a month, he started for another geological excursion toward the Rio Pecos.