Owing to the error in taking Bearings

Owing to the error in taking Bearings, that ever accompanies the run?ning of a real Arc upon the not quite perfectly spherickal Earth, the Sec?tor will never be set up exactly in the Latitude of the true Line. So Off-sets are figur'd at each Mile, ranging from zero at the eastern end, to whatever the difference in Latitude might prove to be, at the other. These offsets must then be added to the purely geometrical differences, at each Mile, between the ten minutes of Great Circle actually run, and its Chord,— the Line itself,— each time increasing from zero to about twenty-one feet at the halfway point, then decreasing again to zero.
As Fortune had put their first Ten Minutes of Arc close beside Octarara Road, so does their next Stage west allow them to set up the Sector but twenty-six Chains short of the east bank of Susquehanna, a mile and a half of Taverns strung near and nearer along the way up to the Peach Bottom Ferry. On Sunday the twelfth of May, they begin their Zenith Obs again, continuing them till the twenty-ninth. It will be a brisk and pleasant Fortnight beside the broad River, which dashes and rolls 'round two small Islands directly in the line of the Visto. On days of cloud, they endeavor to project the Line across the River, whose breadth they take the occasion to compute,— tho' the task falls mostly to Dixon, being,fake uggs boots, as Mason informs ev'ryone, more Surveyor's Work, really.
Dixon and Mr. McClean,UGG Clerance, along with Darby and Cope, go trudging down to the River to have a look. Common practice would be to measure out a Base Line upon the further Bank, set up there, turn off ninety degrees, put a mark on the near side, come back across, set up at the mark there, and find the angle between the two ends of the Base Line,—
then, with the aid of a book full of logarithms, including those of "Trig" functions, 'twould take but a minute and a half of adding and checking, to find the distance across the River.
"That's how we learn'd in Durham," Dixon recalls, "to measure across places we'd rather not go. Not so much Rivers, of course, as unexpected patches,— sudden entire ranges of Spoil-heaps, or a Grove out in an empty Fell,— certainly nowhere near this d——'d many Trees."
"I've found little Joy in these Situations," offers Mr. McClean, whilst Darby and Cope nod at one another, silent as understudies in the Wings, moving their Lips no more than necessary. Sweating and muttering, all go tramping up and down the Bank, kicking up clouds of Gnats, crush?ing wild Herbs in Blossom, seeking a line of sight that will allow them to use a Right Angle,— a Fool's Errand, as it proves. At length, "Eeh,nike shox torch ii, we'll have to use what Angles we can, then, that bonny with ev'ryone,replica gucci wallets?"
And more than soon enough for the Chain-men, tho' Mr. McClean is shaking his head. "I never get the Figures right."
"Then let huz pre-vail somehow upon Mr. Mason, to review our com?puting,— Angles being the same,— so I surmise,— down here as Out There." Mr. McClean takes over the eighteen-inch Hadley's, and Dixon repeats his Sights with the Circumferentor, obtaining at last an ungainly Oblique Triangle, from which they calculate Susquehanna to be about seven-eighths of a mile across.