August 12, 1878 Monday – The men left Baden Baden by rail and arrived at Lucerne, Switzerland where they joined Livy, the children and the rest of the party who had been there a few days.
August 15 Thursday – The entire Clemens party took a two-day excursion to the Rigi-Kulm. They spent the night in a hotel on the Rigi to watch the sunset and sunrise.
August 21. 1878 The group traveled to Interlaken and from August 23 to the 31st Sam and Twichell went to see the Matterhorn.
From pages 262-3 The Life of Mark Twain - The Middle Years 1871-1891:
On the morning of August 23 Sam and Joe left Livy, Susy, Clara, and the servants in Interlaken and traveled by buggy—a concession to Sam's theumatism—through the Kiental and Frutigen to Kandersteg at the foot of the Gemmi Pass. On August 24 they “skirted the lonely little lake called the Daubensee” and trudged over the pass to Leukerbad. Much as he remembered retreating in time by climbing the volcanoes in Hawaii in 1866, Sam wrote to Livy that evening,
Joe & I have had a most noble day. Started to climb (on foot) at 8.30 this morning among the grandest peaks! Every half hour carried us back a month in the season. We left them harvesting 2d crop of hay. At 9 we were in July & found ripe strawberries; at 9.30 we were in June & gathered flowers belonging to that month; at 10 we were in May... ;at 11.30 we were in April (by the flowers); at noon we had rain & hail mixed, & wind & enveloping fogs, & considered it March; at 12.30 we had snow-banks above us & snow-banks below us, & considered it February.
During the next few days they walked and railed through the Rhone Valley to Visp and St. Niklaus. At three in the afternoon on August 27, nine hours by foot from Saint Niklaus, they reached Zermatt near the Matterhorn, where they registered at the Cervin Hotel. Sam was awed by the “tall sharp peak” of the massif, describing in Whitmaniacal prose “his vast wreaths of white cloud circling about his summit & floating away from it in rolling & tumbling volumes twenty-mile wreaths floating slanting toward the sun.” Still, he was disgusted by the squalor in the villages of this “wretched canton.” The “narrow ill paved alleys or streets” of St. Niklaus and Zermatt, he noted, ran foul with “liquid dung,” filthy fluid he euphemistically termed “fertilizer-juice” in A Tramp Abroad. “The only clean members of the family,” he insisted, “are the cattle.” The morning of August 30, after day trips to the Gornergrat and the Gorner glacier, Sam and Twichell left Zermatt in a wagon and a rainstorm to retrace their steps to St. Niklaus, then tramped seven miles downhill to Visp, where they registered at the Hétel du Soleil. The next day they traveled by rail to Bouveret and by boat across Lake Geneva to Lausanne, where they rejoined the family at the Hôtel Beau Rivage.”