A correspondent of Nature writes that, in roaming over the hills and rocks in the neighborhood of Kendal, near Lancaster, England, which are composed chiefly of limestone, he had often found what are called “musical stones.” They are generally thin, flat, weather-beaten stones, of different sizes and peculiar shapes, which, when struck with a piece of iron or another stone, produce a musical tone, instead of the dull, heavy, leaden sound of an ordinary stone. The sound of these stones is, in general, very much alike, but sets of eight stones have been collected which produce, when struck, a distinct octave.

— Frank H. Stauffer, The Queer, the Quaint and the Quizzical, 1882

See also The Musical Stones of Skiddaw.

In The Atmosphere (1873), Camille Flammarion quotes a M. Grellois, who was traveling in northern Algeria in the summer of 1847:

I was proceeding one very hot day on horseback, at a walking pace, between Ghelma and Bône, in company with a young friend who has since died. When we had arrived within about two leagues of Bône, toward one in the afternoon, we were suddenly brought to a halt at a turn in the road by the appearance of a marvelous picture unfolded before our eyes. To the east of Bône, upon a sandy stretch of ground which a few days before we had seen arid and bare, there rose at this moment, upon a gently sloping hill running down to the sea, a vast and beautiful city, adorned with monuments, domes, and steeples.

That sounds like a mirage, but Grellois says the travelers observed the city for nearly half an hour, and that “reason refused to admit that this was only a vision.” “Whence came this apparition? There was no resemblance to Bône, still less to La Calle or Ghelma, both distant twenty leagues at least. Are we to suppose it was the reflected image of some large city on the Sicilian coast? That seems to me very improbable.”

On Aug. 9 each year in the little Alaskan town of Kotzebue, the sun sets twice.

Due to a quirk of the town’s location and time zone, the sun goes down just after midnight on that day—and then again just before the following midnight.

Over water, or a surface of ice, sound is propagated with remarkable clearness and strength. … Lieut. Foster, in the third Polar expedition of Capt. Parry, found that he could hold conversation with a man across the harbor of Port Bowen, a distance of six thousand six hundred and ninety-six feet, or about a mile and a quarter. This, however, falls short of what is asserted by Derham and Dr. Young, — viz., that at Gibraltar the human voice has been heard at the distance of ten miles, the distance across the strait.

— Charles Carroll Bombaugh, Gleanings for the Curious from the Harvest-Fields of Literature, 1890