Excerpt from:
"Eruption of Mount Hood, Extract from a private letter dated San Francisco, Sept. 4th 1859, IN:
The American Journal of Science and Arts, November 1859, Vol.XXVIII, p.448.
Eruption of Mount Hood, (Extract from a private letter dated San Francisco, Sept. 4th, 1859). --
"On the 15th, 16th and 17th of August, 1859, the atmosphere at this place (Portland, Oregon,) began to grow quite sultry, on the 17th the air very soon after ten o'clock became exceedingly hot, a very unusual circumstance here. The sky up to noon was nearly cloudless, but after meridian the heavens assumed an unusual aspect; on directing our attention toward Mt. Hood we all observed a most singular collection of clouds hovering over the summit, having a light silvery aspect, mingled with others of darker hue, heavy and apparently lowering. Up to the close of the following day nothing else unusual had occurred, the clouds still hanging over the mountain. On the evening of the 18th flashes of light were frequent from about the summit, and a full volume of illuminated vapor at times would ascend. On the 19th and 20th heavy volumes of cloudy vapor continually poured out from the crater, and on the evenings of these days the shafts of flame were almost constant, the light was continuous through the night. On the 20th the smoke cleared up for a short time affording a view of the summit, it was observed to have changed its aspect to the naked eye, but with glasses the upper northwest side of the summit had disappeared entirely, it had the appearance of an immense gap, the presumption is that it has fallen in. There are parties on their way to the mountain to explore it, and on their return I will write you again."
Digital version of the American Journal of Science and Arts
was found at "Google Books" Website (2009).