Far enough west

Far enough west, and they have outrun the slowly branching Seep of Atlantic settlement, and begun to encounter towns from elsewhere, com?ing their way, with entirely different Histories,— Cathedrals, Spanish Musick in the Streets, Chinese Acrobats and Russian Mysticks. Soon, the Line's own Vis Inertiae having been brought up to speed, they dis?cover additionally that 'tis it, now transporting them. Right in the way of the Visto some evening at Supper-time will appear the Lights of some complete Village, down the middle of whose main street the Line will clearly run. Laws continuing upon one side,— Slaves, Tobacco, Tax Lia?bilities,— may cease to exist upon the other, obliging Sheriffs and posses to decide how serious they are about wanting to cross Main Street. "Thanks, Gentlemen! Slaves yesterday, free Men and Women today! You survey'd the Chains right off 'em, with your own!"
One week they encounter a strange tribal sect, bas'd upon the worship of some celestial Appearance none but the Congregation can see. Hun?gry to know more about the Beloved, ignoring the possibility of a nega?tive result, recklessly do they prevail upon the 'Gazers to search scientifickally, with their Instruments, for this God, and having found its position, to determine its Motion, if any. It turns out to be the new Planet, which, a decade and a half later, will be known first as the Georgian, and then as Herschel, after its official Discoverer, and more lately as Uranus. The Lads, stunn'd, excited, realize they've found the first new Planet in all the untold centuries since gazing at the Stars began. Here at last is the Career-maker each has dreamt of, at differing moments and degrees of Faith. "All we need do is turn," cries Mason,— "turn, Eastward again, and continue to walk as we ever have done, to claim the Prize. For the first time, we may forget any Obligations to the current Sky,— for praise God (His ways how strange), we need never work again, 'tis t'ta to the Mug's Game and the Fool's Errand, 'tis a Royal Entrance at Life's Ridotto, 'tis a Copley Medal!"
"Eeh!" Dixon amiably waves his Hat. "Which half do thou fancy, obverse or reverse?”
"What?" Mason frowning in thought, "Hum. Well I rather imagin'd we'd...share the same side,— a Half-Circle each, sort of thing—"
Yet by now they can also both see the Western Mountains, ascending from the Horizon like a very close, hitherto unsuspected, second Moon,— the Circumferentor daily tracking the slow rise in vertical angle to the tops of these other-worldly Peaks. They are apt to meet men in skins, and Indians whose Tongue none of the Party can understand, and long strings of Pack-Horses loaded with Peltry, their Flanks wet, their eyes glancing 'round Blinders, inquiring... Survey Sights go on now for incredible Hundreds of Miles, so clear is the Air. Chainmen go chaining away into it, and sometimes never come back. They would be re-discover'd in episodes to come, were the episodes ever to be enacted, did Mason and Dixon choose not to turn, back to certain Fortune and global Acclaim, but rather to continue West, away from the law, into the savage Vacancy ever before them—