On May 10, 1899, Sam wrote in a letter, "We shall reach London May 31, by way of Bremen & the steamer “Lahn” to Southampton.

David Fears wrote (for the August 3, 1899 entry) of  a letter to Rogers: "I am unspeakably sorry to lose the steam yachting and the Fairhaven visit, and I wasn’t expecting to lose the whole scheme, but the Swedish project made a sudden and radical change in our plans. You see, Jean’s health has made no real and substantial progress in the past 3 years. None whatsoever. We had tried the baths, and the doctors and everything—all no good. What should we do? For one, I was willing to try anything that might turn the tide— except Christian Science.

...

Mark Twain stayed in Vienna with his wife Olivia and his daughters Clara and Jean from the end of September 1897 till the end of May 1899, except for a few weeks in the summer of 1898, spent at the summer resort of Kaltenleutgeben near Vienna.

The family took quarters in Hotel Metropole, beautifully situated on the Franz-Joseph's Quay, on the right bank of the Danube Canal.  Later they moved to the Hotel Krantz, opposite the old Capuchin Church and Monastery, in the center of the city.

Sam’s notebook:

Sund, July 25. At 6 this am, for the first time in the week, sun & surface were just right for mirror-effects—so the lake was full of pictures.

Twain spent his time in England working on his book, Following the Equator.  Isaac Gewirtz, Mark Twain A Skeptic's Progress  pg 87-9, writes of this:

We sailed on the 15th of July in the Norman, a beautiful ship, perfectly appointed. The voyage to England occupied a short fortnight, without a stop except at Madeira. A good and restful voyage for tired people, and there were several of us. I seemed to have been lecturing a thousand years, though it was only a twelvemonth, and a considerable number of the others were Reformers who were fagged out with their five months of seclusion in the Pretoria prison.

This was Mark Twain's second visit to the African continent. In "The Innocents Abroad" he visits North Africa. Now, three decades later, he visits South Africa as presented in "Following the Equator". Rasmussen notes "While he had mixed feelings about Britain's proper role in the South African (Boer) War, he was unreservedly opposed to the ruthless commercial exploitation of the Congo Free State -- and denounces it in "King Leopold's Soliloquy".

This is indeed India!

After visits to Maryborough and some other Australian towns, we presently took passage for New Zealand. If it would not look too much like showing off, I would tell the reader where New Zealand is; for he is as I was; he thinks he knows. And he thinks he knows where Hertzegovina is; and how to pronounce pariah; and how to use the word unique without exposing himself to the derision of the dictionary. But in truth, he knows none of these things. There are but four or five people in the world who possess this knowledge, and these make their living out of it.

Mark Twain was in Australia from September of 1895 to January of 1896. Part of that time, some of November and December, was spent in New Zealand. Australia was not a unified country at this time but consisted of seven separate British territories. Twain visited the four southeastern territories: New South Wales, Victoria, South Australia and Tasmania. He saw the shoreline of Western Australia from his ship, the Oceana, en route to Ceylon. It anchored off-shore from Albany January 4th, 1896.