Royal Observatory Greenwich | S.E. | 1858 August 10
My dear Sir
I was at the Hospice of the Grimsel1 on July 28, and found your name entered on July 27. I wish that fortune had so far helped me as to give me a walk on the Unter Aar Gletscher2 with you: my solitary walk (i.e. with my two sons,3 like the spectator’s ‘enter a king and two fiddlers solus’4) was however a very interesting one, and I would give much for a repetition of it.
I had in my hand the copy of Agassiz’ map5 (made at the Royal Institution)
with the accuracy and value of which I was delighted. I do not know a more striking sight than that of the subordinate moraines6 from the Studer Horns7 and other places sweeping round the promontory in the south area of the glacier opposite the Abschwung;8 or than that of the two moraines from the two sides of the Abschwung, a few yards apart, one entirely of granite and the other entirely of schist.9
I looked with some care for the critical phenomena, especially those of the bands of ice, and confess myself entirely puzzled. I had been upon the lower Glacier of Grindelwald10 (a very interesting one) and there I saw very numerous instances of the lenticular form which you have pointed out. On the Lower Aar Glacier11 I did not see one: I only saw the interminable long lines of band: I call them interminable because in no case did I see a termination except where cut off by a crevasse.
The terminal face of the Rhone12 shews well the bands transversal to the crevasses (they look like the fan-groining13 in the roof of King’s College Chapel)14, and in passing in front of it I remarked that in one part the upper beds of ice, as divided by the horizontal bands, were pushed over the lower beds, so as to form what carpenters call a rabbet.15 This looks very much like formation of the bands by bed sliding on bed.
There is a meteorological phenomenon which perplexes me. When the lower
end of the valley, below the glacier front, is choked with mist and rain-storm, the upper end of the glacier is perfectly free, and even the mountain tops are sometimes
seen. I remarked this in two instances.
I am, my dear Sir, | Yours very truly | G.B. Airy
Professor Tyndall
RI MS JT/1/A/35
RI MS JT/1/TYP/1/25
Grimsel: see letter 1517, n. 2.
Unter Aar Gletscher: see letter 1305, n. 2.
my two sons: Wilfrid and Hubert Airy. See letter 1518, n. 3.
‘enter a king and two fiddlers solus’: quoted by English essayist Joseph Addison (1672–1719) in his daily newspaper The Spectator (in its first year, issue 29 of 3 April 1711), which he founded in March 1711 with Richard Steele. The quote refers to, in theater, instrument players providing music during an important character’s solo speech.
Agassiz’ map: presumably a copy of the map made by Johannes Wild for Agassiz’s Nouvelles études et expériences sur les glaciers actuels (1847). See letter 1302, n. 11.
moraines: see letter 1415, n. 17.
Studer Horns: a smaller alpine peak on the eastern side of the Finsteraarhorn.
Abschwung: see letter 1436, n. 11.
schist: a crystalline rock whose component minerals are arranged in a more or less parallel manner (OED).
lower Glacier of Grindelwald: see letter 1312, n. 3.
Lower Aar Glacier: see letter 1305, n. 2.
Rhone: see letter 1297, n. 12.
fan-groining: vaulting composed of pendant semi-cones covered with foliated panel-work (OED).
King’s College Chapel: the gothic chapel of King’s College, Cambridge, took over a century to complete after construction began in 1446. It is noted for its fan-vaulted ceiling.
rabbet: a channel, groove, or slot, cut along the edge or face of a piece of wood or other material and intended to receive the edge or end of another piece or a tongue made specially to fit (OED).
Please cite as “Tyndall1541,” in Ɛpsilon: The John Tyndall Collection accessed on