^{page 260 note *} This formula obviously includes the case of conduction between the soil and the fiist elements of the atmosphere too—provided we make no assumptions on the nature of the function ϕ(λ). If, in what follows, we simply speak of radiation between soil and air, we always tacitly refer to the piobable existence of such conduction.

^{page 269 note *} Researches on Solar Heat and its Absorption by the Earth's Atmosphere. A Eeport of the Mount Whitney Expedition.

^{page 271 note *} I have to correct a mistake in this part of the paper already published, caused by an erroneous theoretical consideration, which, however, does not alter the result derived from the integral.

At stations where the thermometer is too much protected by houses, etc., and where the sun's rays have not sufficient access to the neighbouring ground, we generally observe a diminution of the daily range connected with a retardation of the time of maximum temperature. It is not difficult to find the cause of these phenomena—first, in the diminution of solar radiation acting upon the neighbouring soil; and, secondly, in the continuous currents of hotter air, which are caused by the upward direction of the currents on the roofs of the houses, and which mix with the colder air near the protected position of the thermometer. Hence we have to alter the above equations by taking a smaller value of K, and changing the sign of the expression dk cos (ζ – ν′). On a much larger scale the same phenomenon appears in mountainous countries, where currents of heated air flowing up a valley during day-time give the same peculiar character to the daily curve of its temperature.

^{page 274 note *} Supplementband zum Repertorium für Meteorologie, St Petersburg, 1881Google Scholar.