_____Pliny suggests that they set up the orrery so Cherrycoke can demonstrate the transit of Venus, and Pitt gets out the candle that represents the sun. Their sister Tenebrae, meanwhile, indulges in some mild flirtation with Cousin Ethelmer. The orrery includes the new "Georgian" planet, which would later be named Uranus, because its creator, "Dr. Nessel, the renown'd German Engineer," had traveled to Philadelphia to update, free of charge, the orreries he had built in America. He has even given some surface features to the new planet, which inspired the children to write "a Book, History of the New Planet, the Twins providing the Wars, and Brae the scientifick Inventions and Useful Crafts."
Cherrycoke explains why numerous observations of the transit are necessary to determine "the value of the Solar Parallax." That is, we want to determine the size of the Earth, and the observations of the transit allow us to calculate it as if one were standing on the surface of the sun. DePugh, "the son of Ives LeSpark, like Ethelmer home on a Visit from School, in this case from Cambridge," refers to the sought-after calculation as "A Vector of Desire," a Pynchonian joke on a Lacanian phrase. Cherrycoke calls this "the phrase exact."
We return to the scene in Cape Town where "odd behavior like it, is going on all over the World all day long that fifth and sixth of June, in Latin, in Chinese, in Polish, in Silence, -- upon Roof-Tops and Mountain Peaks, out of Bed-chamber windows, close together in the naked sunlight whilst the Wife minds the Beats of the Clock." They need to record "four instances of perfect Tangency": the moments when the planet first touches the outer edge of the sun and when it is fully within the circumference, and the corresponding moments as it leaves the solar disk. But it is cloudy on the days leading up to the event. Mason and Dixon are nevertheless calm but they notice that "the Zeemans and the Vrooms speed about in unaccustom'd Bustle," which causes Mason to remark, "Dutch Ado about nothing." (Pynchon leaves no opportunity unpunned.)
The day comes, and the sky is clear enough for observation. They observe carefully, but "Whatever the cause, the times [Dixon] records are two to four seconds ahead of Mason's." And then comes anticlimax.
As before the Transit the month of May crept unnaturally, so, after it, will June, July, August, and September hasten by miraculously, -- till early in October, when Capt. Harrold, of the Mercury, finds a lapse in the Weather workable enough to embark the Astronomores, and take them to St. Helena in.... After the Transit, Astronomers and Hosts walk about for Days in deep Stupor, like Rakes and Doxies after some great Catastrophe of the Passions.The pursuit of Mason by the Vroom women ends when some young men arrive at the Cape, "a Heaven-sent Source of White Blood.... Johanna can almost see those Babies now, up on the Block, adorable enough to sell themselves, kicking their feet in the air and squealing." Idled, Mason inquires of Dixon about the Quaker practice of sitting quietly until one feels the presence of the spirit, but Mason is too eager for the experience and "keeps jumping up, to run and interrupt Dixon, who is trying to do the same, with news of his Progress, '' 'Jere! I think it almost happen'd! D'ye get a kind of rum sensation here,' -- touching the center of his Forehead, -- 'is that it?'" But they finally give it up after "Mason, in his Chair, falling asleep, topples with a great Crash, or Dixon decides he'll step out after all, nip down to The World's End, and see what the Cape Outlawry may be up to." Finally, they sail away from the Cape, with "no one ... there at the Quay to say good-bye but Bonk, the police official who earlier greeted them."
Cherrycoke's audience is joined by Aunt Ephrenia, "careering into the room with her Oboe and an armload of sheet-music," and as she carves a reed from her oboe we learn that she was once abducted by Barbary pirates and kept in a sultan's harem. Cherrycoke continues with "a part of the Tale that I miss'd," which is the experiences of Mason and Dixon in St. Helena, where they met up with the astronomer royal, Nevil Maskelyne. Uncle Ives asks how they are to know what happened there, but Cherrycoke continues with the story nevertheless. St. Helena, he says, is "an infamous Port of Call, quite alone in the mid-Atlantic, a Town left to shift as it may, dedicated to nought but the pleasures of Sailors, -- which is to say, ev'ry species of Misbehavior, speakable or not."
Maskelyne is there to observe Sirius, "the Island's Zenith-Star." But it's hardly a pleasant place to be.
The Town has begun to climb into the Ravine behind it, and thus, averaged overall, to tilt toward the sea. After Rain-Storms, the water rushes downhill, in Eagres and Riffles and Cataracts, thro' the town, rooftop to rooftop, in and out of Windows, leaving behind a shiv'ring Dog from uphill, taking away the Coffee Pot, till leaving it in its turn somewhere else, for a Foot-Stool, thus bartering its way out to sea.The residents of the island "make up a mix'd flock":
Convicts being transported to the South Seas for unladylike crimes in England, with St. Helena one of the steps in their Purgatory, -- young Wives on their way out to India to join husbands in the Army and Navy, a-tremble with tales, haunting the Day like a shadow from just beneath the Horizon ahead, of the Black Hole of Calcutta, -- and Company Perpetuals, headed out, headed home, such shuttles on the loom of Trade as Mrs. Rollright, late of Portland, who keeps opium in her patch-box and commutes frequently enough upon the India run to've had four duels fought over her already, though she has yet to see her twenties out.And Mason encounters an old acquaintance, Florinda, whom he met after the death of his wife, when he followed "some of Lust's less-frequented footpaths." He had met her at the hangings at Tyburn, particularly at "the much-heralded Hanging of Lord Ferrers for the murder of Johnson, his Steward."
Mason and Dixon meet with Maskelyne at The Moon, "a punch house on Cock Hill," but Dixon and Maskelyne don't get along particularly well after Dixon, learning that Maskelyne was at Pembroke College, Cambridge, is indiscreet enough to ask him about Christopher Smart, notorious for his insanity. The proprietor of the punch house also can't resist a pun about how Maskelyne is there on "Sirius Business." And Maskelyne is further annoyed by having his birthday celebrated with a cake, reminding him that he has just turned twenty-nine.
Dixon is preparing to return to the Cape, and when Maskelyne steps out, Mason reveals that the instrument Maskelyne is using to measure the position of Sirius doesn't work. Dixon thinks he can fix it, but Mason warns him not to bring up the subject of the instrument with Maskelyne because he has so much invested in it. Dixon is returning to the Cape with the Shelton Clock, and there is a section of dialogue between it and the Ellicott Clock about Dutch clocks, whose mechanisms don't give a warning -- the sound of the mechanism preparing -- before they strike. Mason and Dixon were both annoyed by the surprise striking of the clocks.