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Early American Scientific Instruments and Their Makers
Early American Scientific Instruments and Their Makers Author:Silvio A. Bedini Excerpt: ...Westerly and a straight line continued in that direction ten miles. From the termination of this second line a third making a right angle with it was carried South-Easterly ten miles: and from the beginning on Jones' Point a fourth was carried ten miles to the termination of the third. These lines were measured with a chain which was... more » examined and corrected daily, and plumbed whenever the ground was uneven, and traced with a transit and equal altitude instrument which I constructed and executed in 1789 and used in running the Western boundary of the State of New York. This instrument was similar to that described by Le Monnier in his preface to the French "Histoire Celeste." . All the lines in this city in which I have been concerned were traced with the same instrument which I used on the lines of the ten mile square but as the Northern part was not finished when I left that place, I cannot pretend to say what method has since been pursued. Deposit of Andrew Ellicott Douglass of Flagstaff, Ariz., in 1931. USNM 152080. Figure 10. Pg 137 Figure 73.« less