Last week, on the 2nd of January, accompanied by a guide, I made the ascent of Snowdon2 from the Victoria Hotel at Llanberis.3 There had been a heavy fall of snow the previous night, which circumstance I hoped would give me an opportunity of repeating your experiments relative to the blue colour of newly-fallen snow in Switzerland;4 nor was I disappointed. As soon as I arrived at a sufficient altitude for the snow to be one foot thick, viz., 1900 feet from the sea, on making the hole with the baton I was delighted to find the blue colour, but rather pale. As we ascended the mountain, we came into a dense mist with the snow deeper, and the blue colour became darker every step until we reached the summit, when the colour was as dark as that of the firmament. The most beautiful colour, however, was in the natural cracks and holes in the drifted wreaths of snow, caused, I suppose, by the particles of snow not having been compressed on each side the cracks or holes, and the reflections consequently more numerous. The light in the crevices of the snow on the side of the mountain overlooking Glaslyn5 was exceedingly beautiful. The thermometer on the summit was 28 deg. Fah., and the calculated height by an aneroid 3595 feet above the sea.
‘THE BLUE SNOW QUESTION—ASCENT OF SNOWDON’, Hampshire Advertiser, 24 January 1863, p. 2
James Hall: not identified. This letter was reprinted in the Hampshire Advertiser of 24 January 1863 with the introduction: ‘The Athenaeum gives the following extract from a letter addressed to Professor Tyndall by Mr. James Hall’.
Snowdon: the highest mountain in Wales.
Victoria Hotel at Llanberis: the Victoria Hotel lies at the foot of Snowdon and remains popular with climbers.
your experiments… in Switzerland: this refers to Tyndall’s observations in the 1850s on glaciers and mountain passes (see e.g,. Glaciers of the Alps, p. 29 and p. 83 and Tyndall’s journal entry of 4 September 1856 (RI MS JT/2/13c/899). Presumably Hall read them in Glaciers of the Alps or heard them at a lecture.
Glaslyn: translated as ‘blue lake’ in Welsh, Glaslyn is a lake found on the eastern flanks of Snowdon.
Please cite as “Tyndall1968,” in Ɛpsilon: The John Tyndall Collection accessed on