I've been working to retrace the south line of Ohio's Connecticut Western Reserve.
The original survey was done in 1797 for the first 55 miles or so and then continues later.
The first 62 miles of this line was to follow the 41 st latitude, but they started quite a bit south of that point.
The notes I have indicate that the crew was at 41d00m20s, and so the crew went 20 seconds farther south to begin. They actually started at about the 40d59m20s . . . roughly(actually about the 40d59m18.5s).
This makes me wonder if there could've been calculations involved whereas the crew felt they were 20 seconds north, while they were in fact 20 seconds south.
The run west, for the first 62 miles hold true at 40d59m18s to 40d59m19s, which makes me think the equipment was probably pretty precise for 1797.
I wonder if anyone has any ideas of what "precision", equipment might've been in use in 1797 in America?
I'm not really sure that you are asking the right questions here....
You can do really GOOD work, with a compass, and chain, if you work hard, and are careful. And, you can do some really shoddy work, if you don't really care.
So, go and retrace it, and bring back the answer of how well they did.
(Easy now, I am not jumping you, I am just saying that I have done LOTS of retracement, and this is my experience speaking)
Carry on..
Nate
Just curious, Did you get copies of the original notes?
Work like that in 1797 had to the cutting-edge kind of stuff for back then, I'm sure.
I've read the notes from several of the surveys (1870's) in what eventually became Oklahoma and the predominant procedures used for lat/long was astronomical observations. Although in later (1890's and later) notes the solar observations seem to have become more popular.
80 years prior to that I would assume they probably depended on astronomical observations. Of course, the precision of the equipment was just as important as the precision of the ephemeris data you had available.
Here's a pic of a Pike & Sons transit from about 1830:
I noticed it has a full zenith circle, probably necessary for good star-shots. I don't know what precision the vernier read to, but I bet multiple observations were the norm. With lots of checking and rechecking. You would be lucky if it read correctly to the nearest minute.
A quick guess of 20" of arc would be about 2000' maybe. Not bad, it was a big country back then.
Maybe your answer is in the letters by Moses Warren Jr. at the William Clements Library. Says they have some maps of the reserve there too.
http://quod.lib.umich.edu/c/clementsmss/umich-wcl-M-1612war?view=text
Warren began working as a surveyor and mapmaker, and in 1796 was made deputy land surveyor of Connecticut. In 1796-1797, he surveyed modern-day Ohio with the Connecticut Land Company, and assisted General Moses Cleveland in laying out the city of Cleveland, Ohio. Thereafter, he and his wife settled in New London, Connecticut, and Warren continued his cartographical work, and published several influential maps with George Gillet. Warren died in 1835.
In order to terminate land claims of Connecticut based upon its colonial charter, Congress in 1786 granted the state a sizeable territory along Lake Erie, just west of Pennsylvania, which became known as the Western Reserve. General Anthony Wayne's successful campaign against the Indians in 1794 made settlement feasible, and in 1796 the state sold the vast portion east of the Cuyahoga River to the Connecticut Land Company.
Ellicott's Line (one of them) in 1786 was the western boundary of Pennsylvania, run north from the western terminus of the Mason-Dixon line. It was supposedly the first major public survey of western lands done with a transit instrument. Perhaps one was available in the Western Resrve.
The transit line run by Ellicott was run north from mountain top to mountain top with the instrument observed in face one and face two multiple times at each setup. It was felt by the survey party that by the time they reached the Ohio River, crossed to the north side, and set the POB for the original PLSS, that they were not off line more than a quarter of an inch in the entire line run north from the Mason-Dixon line. In fact they were off by about forty feet.
A Rittenhouse Compass would have also been a likely suspect:
http://invention.smithsonian.org/resources/online_articles_detail.aspx?id=686
Maybe a better choice for running a parallel of latitude.
