On a seaside holiday at Calais with his family in August 1869, French chemist and meteorologist Gaston Tissandier chanced to see a poster advertising a balloon launch from the central square the next day, as part of festivities celebrating Emperor Napoleon III. Going straight to the aeronaut’s hotel, he talked himself onto the voyage. Undaunted by wild nightmares of bursting balloons, his family’s strident pleas not to risk his life, and the blinding storm battering the coast, Tissandier arrived at the launch site at dawn, equipped only with life vests purchased from the Calais Humane Society. Despite a small trial balloon smashing into a bell tower and then being flung by the storm out over the wide expanse of the North Sea, the intrepid aeronauts jump into the wicker basket, a military band strikes up a march, and off the Neptune rises, 4,000 feet in a single bound.

Swept away by the sight of both the ant-like throng of spectators along Calais’ lilliputian shore below and a mirage image of the Calais-Dover ferry and other ships cast upon a cloud above, Tissandier is understandably unnerved that they are on a course not for the English coast as planned, but the open ocean. At 5,200 feet, the pilot notices that the cumulus clouds 2,000 feet below them are flying on a southwest course straight back to Calais, and, after dropping some of their sand ballast, they are soon floating over the Calais jetty — where Tissandier spies his younger brother Albert waving to him.

Continuing west along the French coast until nightfall, they throw out the Neptune’s grapnel when they sight a lighthouse-bearing cape, and the balloon and basket smash into a sand dune, scattering a terrified flock of sheep and shepherds. The lighthouse keeper greets them and promptly informs them that they have come down but a few hundred yards from the tomb of Pilâtre de Rozier — the first human being ever to leave earth (in 1783) in a Montgolfier, and who also became humanity’s first air crash victim in this very same dune field but two years later.

Every single one of Travels in the Air’s balloon expedition accounts presents this same exhilarating conjunction of chance, contingency, and caprice as the brave but often hapless aeronauts venture cloudward. Editor James Glaisher’s sober, scientific reports contrast with the unbridled Romanticism of his French colleagues’ — Tissandier, Wilfrid de Fonvielle, and Camille Flammarion — but all are united by the absolute novelty of their endeavor. Carried to dizzying heights where these gifted scientific communicators begin to build a picture of Earth’s subtle atmospheric organism, we are most moved by countless carnivalesque moments: coming face-to-face with spiders and butterflies a mile above the ground; a dutiful customs officer suspicious of coastal smuggling demanding the aeronauts’ passports; the discovery that tossing chicken bones from lunch will send the silken bubble further aloft as surely as if they had dropped a sandbag. Everywhere the French balloonists meet the same greeting as they return to earth: “Come down! Come down! Dinner is waiting for you!”

As chance would have it, just as James Glaisher was preparing Travels in the Air for publication in London, Napoleon III declared war on the Prussian Empire, leading to the German army’s blitzkrieg and siege of Paris in mid-September 1870. The first edition ended with Glaisher’s fervent call for redoubled commitment to the use of tethered “captive” balloons for scientific investigation. Penned but a month after the lifting of the siege in March 1871, this second and revised American edition of Travels in the Air (which includes half a dozen of Albert Tissandier’s striking chromolithographs) opens with Glaisher’s admission that his call had been regretfully met thanks to France’s misfortunes. For four months, balloons afforded over two million captive Parisians their sole means of contact with the rest of the nation. Sixty-seven manned flights carried military dispatches and letters out of the city — and also ferried homing pigeons, which later returned bearing microfilm messages. The gossamer invention, which before the siege had been universally derided as “good for nothing”, suddenly changed the conditions of modern warfare, while showing the world that Montgolfier’s nearly century-old caprice was simultaneously practical and patriotic.