Whilst daylight is the principal cause of the diurnal inequality, it is not the only cause, otherwise there would be as many auroras in the morning (forenoon) as in the evening (afternoon).
The two last curves in the diagram contrast the diurnal variation at Kew in potential gradient and in barometric pressure for the year as a whole.
Euphratean exploration has so far brought to light no traces of ecliptical partition by the moon's diurnal motion, unless, indeed, zodiacal associations be claimed for a set of twenty-eight deprecatory formulae against evil spirits inscribed on a Ninevite tablet.4 The safest general conclusions regarding this disputed subject appear to be that the sieu, distinctively and unvaryingly Chinese, cannot properly be described as divisions of a lunar zodiac, that the nakshatras, though of purely Indian origin, became modified by the successive adoption of Greek and Chinese rectifications and supposed improvements; while the manazil constituted a frankly eclectic system, in which elements from all quarters were combined.
For his demonstration in 1851 of the diurnal motion of the earth by the rotation of the plane of oscillation of a freely suspended, long and heavy pendulum exhibited by him at the Pantheon in Paris, and again in the following year by means of his invention the gyroscope, he received the Copley medal of the Royal Society in 1855, and in the same year he was made physical assistant in the imperial observatory at Paris.
Summer Observations On Mountains Have Shown Diurnal Variations Very Large And Fairly Regular, But Widely Different From Those Observed At Lower Levels.
Associated with the diurnal revolution of the sphere from east to west.
The third line gives the range of the regular diurnal inequality, the next four lines the amplitudes of the first four Fourier waves into which the regular diurnal inequality has been analysed.
The diurnal variation showed only a single maximum and minimum, between 5 and 6 P. M.
The result, if considered alone, inevitably leads to an underestimate of the average amplitude of the regular diurnal variation.
Also the times of beginning and ending are difficult to define exactly, so that several elements of uncertainty exist in data as to the seasonal or diurnal variation.