@bill93 I think longitude is right. This one gives insight into the Jacob's staff.

@geeoddmike A good bit of the math was in place, for sure, though some of it lacked proof. Here's a timeline that might be used to judge the pace of ...

A quick update. Borden revised his ellipsoid in the paper published in the American Philosophical Society's transactions in 1846. Apparently, Superint...

@john-nolton Geodesy being so young in 1830 is one of the things that makes this survey so remarkable. Another is its anticipation of what is now Sta...

@john-nolton If you look carefully at pages 75 and 76 in the 1990 edition of Pearson's "Map Projections Theory and Applications," you will find that ...

@bill-c It was ahead of its time. Here are a couple of quotes. The first is from the "Tables of Bearings, ..." and the second is from the "Account of...

This is from the US Patent Office. Don't see any numbers, but better readers of old cursive may find something of value. ?ÿ

Was there someone in the parked car selling little plastic bags full of something? That might increase the probability of a gathering by a fair amount...

@john-nolton That's pretty neat. Calculate arc to chord ratios given the central angle theta and put them in a table. You can derive his formula from ...

@john-nolton Yeah, dang it, I didn't look closely enough at the table. My reply to my own post above may help reconcile the difference. Thanks for c...

On the other hand, if you're talking about decimal degrees, that makes perfect sense. The proportion 1/10^n = x/3600 can be used to determine how many...

@mightymoe If you spend a little time with Bowditch, you may abandon state plane forever.  

@mightymoe No, I think that the third decimal place is millimeters so the fourth would be tenths of a millimeter.