New Mexicos boundary with Texas is commonly referred to as the Clark boundary. This designation ignores the fact that most of the surveying on the boundary was not done by John H. Clark, but by his colleague of many years John E. Weyss. Both men had first met as members of the Smithsonian Institution, and their following assignment to the International Boundary Commission on the Mexican boundary survey of 1849 led to at least thirty years of cooperation on various surveys.
John Henry Clark (not to be confused with John A. Clark, Surveyor General of New Mexico from 1861 to 1868) was a native of Anne Arundel County, Maryland, were he was born about 1830. Educated as a naturalist at Dickinson College in Pennsylvania, he came to the Southwest in 1849 with Commissioner John Russell Bartlett, not as a surveyor but as a zoologist. He had a sponsor in the person of Spencer F. Baird of the Smithsonian Institution, under whom he had studied when the latter was professor at Dickinson. Clark was assigned to the boundary commission for the purpose of collecting specimen of fish from the Rio Grande and birds and reptiles from the adjoining desert, a job he performed with great diligence. He discovered many previously unknown species, some of which were named in his honor, among them a lizard now known as Clarks Spiny Lizard (Sceloporus clarkii).
In January 1851 Lt. Col. James D. Graham, principal astronomer of the Commission, appointed the well-educated Clark as computer with a salary of $500 per annum and one ration per day. After Brevet Major William H. Emory replaced Graham on the Commission he trained Clark to make astronomical observations and compute geodetic coordinates.
Bartlett was forced out of the boundary commission over the brou-ha-ha about the latitude of the initial point north of El Paso and was replaced in March 1853 by Robert B. Campbell. Under him, an Austrian immigrant engineer by the name of John E. Weyss was added to the Commission, to work as surveyor, topographer, and illustrator. Weyss had come to the United State in 1848 as an assistant in the Smithsonian Institution.
With the ratification of the Gadsden Treaty in 1853 and the appointment in 1854 of Emory as Commissioner to survey the new treaty line, Clark advanced to the position of principal assistant astronomer. In this capacity he made many of the astronomical observations for longitude and most for latitude, including locating the position of the 111th meridian, the angle point in the international boundary just west of Nogales.
As the fieldwork neared completion in the fall of 1855, Emory returned to his Washington office, along with Clark and Weyss, Clark to make computations and Weyss to produce many of the illustrations of the Emory Report. When Col. Joseph Johnston of the First Cavalry at Fort Leavenworth was directed to survey the 37th parallel from Missouri to the 103rd meridian he chose Clark as his chief astronomer and Weyss as a surveyor. This was in May 1857, and by the end of August they had surveyed the 462 miles long latitudinal arc and set the northeast corner of New Mexico Territory.
By now Clark was considered an experienced surveyor-astronomer with the necessary credentials to be picked by the Department of the Interior for a boundary contract. By an act of Congress approved June 5th, 1858, the sum of $80,000 was appropriated to run and mark the boundary line between the Territories of the United States and the State of Texas, , from where the Red River is crossed by the 100th meridian to where the Rio Grande is crossed by the 32nd parallel. A month later Clark was appointed commissioner for the United States.
Texas had appointed William R. Scurry as its representative commissioner, but Scurry was an attorney and in turn hired Anson Mills as his surveyor. Mills, an Indiana native, was a well-known El Paso surveyor who had made the original survey of the townsite (it was he who changed its name from Franklin to El Paso). For his part Clark, who busied himself mostly with establishing points from astronomic observations, left the running of the lines to his friend John E. Weyss. In his autobiography Mills regarded Clark somewhat as a snob, calling him ambitious in his assumption of highly scientific attainments and overbearing to those he deemed not of his equals in such acquirements . Animosities troubled the parties from the start, soon became acute, and Scurry and Mills resigned before the parties had reached the 103rd meridian. Clark had started his survey work on the Rio Grande in January 1859 and by May had run the 212 miles long 32nd parallel. This writer questions his authority to continue the survey on his own after the Texans had departed; nevertheless Clark proceeded to run the 103rd meridian. Lack of water and remoteness from sources of supply made surveying the meridian a disaster; a lot of triangulating but very little actual line running was done, monumentation was almost non-existing, a gap of 69 miles and perhaps twice as much existed in the center, and the meridian was located from two to four miles too far west. [It may be of interest to mention that Clarks 111th meridian in Arizona is likewise about four and a half miles too far west.] While the shoddily executed survey should have been (and probably would have been) rejected by the General Land Office, the Civil War intervened, nobody inspected and Clark got away with it.
John Clarks very common name does not allow me to state with certainty that he served in the Civil War but John E. Weyss became a Union Army major assigned to the engineering staff of the Army of the Potomac. Under generals Rosecrans and Meade he made a name for himself preparing excellent military maps, many of which were later engraved and are sought-after items on the art market today. They include a map he prepared while triangulating under fire at the battle of Petersburg, and a sketch of the Appomattox courthouse at the time of Lees surrender. Copies of an engraved version of a drawing made about 1860 and depicting a survey party at their tent opposite the Texas town of Brownsville are likewise still being sold by art dealers. Much of his artwork is in the collection of the Daughters of the Republic of Texas Library in San Antonio.
In 1872/73 Clark was a civilian astronomer and Weyss a topographer with the party of 1st Lt. George M. Wheeler on his monumental survey of the American West from the 100th meridian to the Pacific. As an artist Weyss made the first drawings of Bryce Canyon and other scenic jewels encountered by the Wheeler survey.
John H. Clark apparently died in 1885, while Weyss who was a permanent resident of Washington D. C. died there in 1903.