Sunday, January 26, 2020

"Following the Footsteps of the Central Pacific Surveyors"

"Following the Footsteps of the Central Pacific Surveyors" by C. Barton Crattie, LS, CFS, CFM, © American Surveyor (Spatial Media, LLC), 1/25/2020. (Article)

"The Survey—it was a charmed life for the time
Anna Ferona Pierce Judah penned these words in a recollection of her husband, Theodore Dehone Judah, some 26 years after his death. ... Don’t forget Ted Judah and Abe Lincoln were both surveyors. ... " [More]

[Courtesy Google Alerts.]

"From T.D. Judah’s Practical Plan
(January, 1857) (edited)

The engineer in charge of the survey goes over the country upon which it is proposed to construct a line, and carefully examines the ground with reference to the proposed location. He notes its character, water-courses, ravines, undulations of the ground, crossing points for rivers and decides the general course of the line. This done, he organizes a party, composed of what is usually termed a transit and leveling party.

The business of the transit party is to run a line over the route indicated, measuring distances with a chain, and taking courses or direction of the line by compass or goneometer (a transit with two telescopes mounted above one and the other on the same axis to enable measuring the angle twice for a check), leaving stakes every one hundred feet ... as guides for the leveling party. The results are put on paper and gives ... a correct representation of the line, showing curves, tangents, the crossing of roads, rivers, farms, townships, names of land owners and all points of interest along the line.

The leveling party follows the transit party, and runs, with the utmost accuracy, a line of levels, touching upon each stake, taking observations of the undulation of the ground. ... This plotted gives what is called a profile ...

A topographer is also furnished, whose business will be to sketch topography, taking notes of every feature presenting itself.

Another leveling party is provided for the purpose of running a test level. The consequences of an error ... on so long a line of surveys would be so annoying ...

... the Engineer ... knows that ... this will be over level, open country, offering no obstacles, and that an ordinary party, on preliminary surveys, will make three miles per day without difficulty ...