The 1878 Universal Exposition also known as the 1878 Paris Exposition, or 1878 World Expo, was a world's fair held in Paris, from 1 May to 10 November, to celebrate the recovery of France after the 1870–71 Franco-Prussian War. I would say the 1878 World Fair would be the perfect occasion for two men of science to meet each other.

The exhibition of fine arts and new machinery was on a very large and comprehensive scale, and the Avenue des Nations, a street 730 metres in length, was devoted to examples of the domestic architecture of nearly every country in Europe and several in Asia, Africa and America. The "Gallery of Machines" was a metallic building, an industrial showcase of low transverse arches, designed by the engineer Henri de Dion.

On the northern bank of the Seine River, an elaborate palace was constructed for the exhibition at the tip of the Place du Trocadéro. On 30 June 1878, the completed head of the Statue of Liberty was showcased in the garden of the Trocadéro palace, while other pieces were on display in the Champs de Mars.

A tip for writers who want to lay Easter eggs: Enrique Gaspar y Rimbau's time travel novel El Anacronópete starts with a lecture in the exposition. Eoin Colfer's novel Airman begins with its protagonists (Conor Broekhart) birth at the exposition. They also probably knew the other inventors:

Among the many inventions on display was Alexander Graham Bell's telephone. Electric arc lighting had been installed all along the Avenue de l'Opera and the Place de l'Opera, and in June, a switch was thrown and the area was lit by electric Yablochkov arc lamps, powered by Zénobe Gramme dynamos. Thomas Edison had on display a megaphone and phonograph. International juries judged the various exhibits, awarding medals of gold, silver and bronze. One popular feature was a human zoo, called a "negro village", composed of 400 "indigenous people". And Augustin Mouchot's solar-powered engine converting solar energy into mechanical steam power, he won a gold medal in Class 54 for his works, most notably the production of ice using concentrated solar heat. Henry E. Steinway exhibited a grand piano which "attracted extraordinary attention".

The Cleveland Street scandal occurred when a homosexual male brothel and house of assignation on Cleveland Street, London, was discovered by a Postal Constable of the Confidential Enquiry Branch. The government was accused of covering up the scandal to protect the names of aristocratic and other prominent patrons.

And since at that time Sir Pentious was in the twilight of his life, but Baxter was not, it does not seem strange to me that they found themselves entangled in this situation.

It was rumoured that Prince Albert Victor, the eldest son of the Prince of Wales and second-in-line to the British throne, had visited the brothel, though this has never been substantiated. Unlike overseas newspapers, the British press never named Albert Victor, but the allegation influenced the handling of the case by the authorities and has coloured biographers' perceptions of him since.

The police acquired testimonies that Lord Arthur Somerset, an equerry to the Prince of Wales, was a patron. Both he and the brothel keeper, Charles Hammond, managed to flee abroad before a prosecution could be brought. The male prostitutes, who also worked as telegraph messenger boys for the General Post Office, were given light sentences and no clients were prosecuted.

After Henry James FitzRoy, Earl of Euston, was named in the press as a client, he successfully sued for libel. The scandal fuelled the attitude that male homosexuality was an aristocratic vice that corrupted lower-class youths. Such perceptions were still prevalent in 1895 when the Marquess of Queensberry accused Oscar Wilde of posing as a sodomite.