[40] I have corrected this slight inadvertence. We owe the name to Hooker.

[41] Both Professor Helmholtz and I have since agreed to consider the physical cause of regelation an open question.

[42] I am continually indebted to this able mechanism for prompt and intelligent aid in the carrying out of my ideas.

[43] At this time I was brooding over experiments on the absorption of radiant heat by aqueous vapour.

[44] The cleat is a T-shaped mass of metal employed for the fastening of ropes.

[45] There is, it will be seen, a fair agreement between these impressions and those so vigorously described by a scientific correspondent of the ‘Times.’

[46] Esparto is a kind of grass now much used in the manufacture of paper.

[47] In this essay Mr. Busk refers to the previous labours of Mr. Smith, of Jordan Hill, to whom we owe most of our knowledge of the geology of the rock.

[48] No one can rise from the perusal of Mr. Busk’s paper without a feeling of admiration for the principal discoverer and indefatigable explorer of the Gibraltar caves, the late Captain Frederick Brome.

[49] A note, written to me on October 22, by my friend Canon Kingsley, contains the following reference to this point: ‘I have never seen the Lake of Geneva, but I thought of the brilliant dazzling dark blue of the mid-Atlantic under the sunlight, and its black-blue under cloud, both so solid that one might leap off the sponson on to it without fear; this was to me the most wonderful thing which I saw on my voyages to and from the West Indies.’