Surveying Instruments Owned by John Lukens' (Surveyor General of PA) Estate in 1790
Most American collectors focus their collections on Compasses and Transits made by U.S. Makers. As the Lukens estate sale listing shows, however, there were a good number of surveying instruments imported into early America (mostly theodolites). And there were some unsigned instruments made in America but based on a Euro-design (Semicircles) that have largely remained off collectors' bucket lists. I believe that picking up one or two of these instruments would add a good deal of flavor to any well-developed American surveying instrument collection.
These instruments had one HUGE advantage over surveyor compasses - these instruments could measure angles independently of the needle. The surveyor compass was good enough for surveying much of the vast amount of cheap land America offered to early Americans, but sometimes a surveyor needed a more accurate instrument - and these were the go to instruments of choice.
Below are links to the three most common non-compass instruments: Simple or Plain Theodolites, Semicircles, and Improved Theodolites.
There were probably a fair number of 4 vaned theodolites imported into America, and even a few were made here.
Semicircles (aka Semi-Circumferentors) like the one above were made in America, typically in the Northeast.
Improved Theodolites were imported into America and were likely considered the most accurate surveying instrument.
Whiteley Instruments first appeared in 1836 based on an 1836 patent, and evolved thereafter.
© 2020 Russ Uzes/Contact Me