[38] Stevenson, “Account of the Bell Rock Lighthouse,” p. 180.

[39] Stevenson, “Account of the Bell Rock Lighthouse,” pp. 222, 223.

[40] “Smeaton and Lighthouses,” p. 97.

[41] Stevenson’s “Account of the Bell Rock Lighthouse,” pp. 52–57.

[42] Stevenson, “Proposals for the Illumination of Beacons and Buoys” (ed. 1870).

[43] In one of the Paris water-pipes, 3120 feet long, M. Biot was able to keep up a conversation, in a very low tone, with a person at the other end.

[44] Alan Stevenson, “Account of the Skerryvore Lighthouse” (ed. 1848), p. 41.

[45] A. Stevenson, “Account of the Skerryvore Lighthouse,” p. 143.

[46] We think, however, that this statement is in great need of verification.

[47] Walter White, “A Londoner’s Walk to the Land’s End,” pp. 192, 193.