Surveying was as much an art as a science
Surveying was first practiced in Texas to define the boundaries of Spanish land grants. As newly appointed Empresario, Stephen F. Austin had the immediate problem of surveying the land for his colonists. The Mexican vara (approximately 33.33 inches) was used as a standard unit. The surveyors hired by Austin were held to his exacting standards in the performance of their trade. They laid out plots for the colonists by using trees marked with the owner’s initials to establish corners and noting every line not bounded by a river. The surveyor’s fee was to be three dollars per mile, payable in cash. The early surveyors used a linked chain twenty varas long. They had a tendency, since the land was cheap and unoccupied, to add twenty to 100 varas to each mile of line to make certain that no one was cheated; hence, a supposed section of land has often been found to contain from one to 100 acres of excess. A compass and a Jacob staff (a vertical rod that penetrates or sits on the ground and supports the compass), were used for running lines. Surveyors could not agree on the declination (angle between magnetic north and true north); some thought it should be east, others thought it should be west; others used no declination at all but simply ran a magnetic course.
Surveyors were required by Spanish and Mexican law to point out to grantees each and every corner of the grant and to tell him “in a loud voice” that he was invested with the property pointed out. The grantee indicated his acknowledgment of the grant by throwing rocks, shouting aloud, firing guns, and making other and sundry noises. With the beginning of Anglo-American colonization, Stephen F. Austin was careful not to issue titles to colonists until a survey had been made. [Texas Historical Foundation, Handbook of Texas.]