the diurnal inequality is shown for " winter " and " summer " respectively.
This is one of the reasons why in the figures for the annual and diurnal variations in Tables I., II.
Some are nocturnal, some diurnal; some catch their prey by speed of foot, some by cunningly lying hid, some by means of silken nets.
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.
He also found a marked diurnal variation, A being considerably greater between 3 and 5 A.M.
Thus he separates the birds of prey into three great groups - (I) the ordinary Diurnal forms, including the Falconidae and Vulturidae of the systematist of his time; but distinguishing the American Vultures from those of the Old World; (2) Gypogeranus, the secretary-bird; and (3) the owls (q.v.).
The species of the genus Lemur are diurnal, and may be recognized by the length of the muzzle, and the large tufted ears.
The diurnal mountain winds are very strongly marked on the Himalaya, where they probably are the most active agents in determining the precipitation of rain along the chain - the monsoon currents, as before stated, not penetrating among the mountains.
The diurnal rotation of the earth furnishes two fixed points or poles, the axis joining which is fixed or nearly so in its direction in space.
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.
A still further facility was given to the use of the filar micrometer by the introduction of clockwork, which caused the telescope automatically to follow the diurnal motion of a star, and left the observer's hands entirely at liberty.'
These demonstrations were of two kinds, one nocturnal, showing the moon and bright stars, the other diurnal, for day scenes.
The diurnal variation in summer at the latter station is shown graphically in the top curve of fig.
The result, if considered alone, inevitably leads to an underestimate of the average amplitude of the regular diurnal variation.
If the pressure alters as the water tank empties, a discontinuity occurs in the trace when the tank is refilled, and a fictitious element may be introduced into the diurnal variation.
It is thus customary in calculating diurnal inequalities either to take no account of days on which there is an appreciable rainfall, or else to form separate tables for " dry " or " fine " days and for " all " days.
The diurnal variation showed only a single maximum and minimum, between 5 and 6 P. M.
The synodical revolution of the moon laid down the lines of the solar, its sidereal revolution those of the lunar zodiac. The first was a circlet of " full moons "; the second marked the diurnal stages of the lunar progress round the sky, from and back again to any selected star.
The island regions of the Pacific are everywhere characterized by uniform high air-temperatures; the mean annual range varies from 1° to 9° F., with extremes of 24° to 27°, and the diurnal range from 9° to 16°.
Nearly all geckos are nocturnal and the pupil contracts into a vertical slit, except in a few diurnal kinds, e.g.
diurnal raptors is the true falcons.
The " Accipitres " are divided into two groups, Diurnal and Nocturnal; but the first of these divisions is separated into three sections: (1) the Vultures of the New World, (2) those of the Old World, and (3) the genus Falco of Linnaeus.
The most careful determinations are affected by systematic errors arising from those diurnal and annual changes of temperature, the effect of which cannot be wholly eliminated in astronomical observation; and the recently discovered variation of latitude has introduced a new element of uncertainty into the determination.
The mountains also introduce controls over the local winds; diurnal warming in summer suffices to cause local ascending breezes which frequently become cloudy by the expansion of ascent, even to the point of forming local thunder showers which drift away as they grow and soon dissolve after leaving the parent mountain.
- Diurnal inequalities such as those of Tables II.
Except at Karasjok, where the diurnal changes seem somewhat irregular, the relative amplitude of the 12-hour term is considerably greater in summer than in winter.
It has several marked deficiencies compared with Australia, among which are the babblers (Timeliidae), weaver birds (Ploceidae), the Platycercinae among parrots, diurnal birds of p rey and the emeus.
The climate is healthy; owing to the elevated situation it is somewhat cold, and is liable to sudden diurnal and seasonal changes; the temperature in January sometimes falls to 4° F.
In habits they are partly diurnal; and live either in burrows among the crevices of rocks, beneath the leaves of aquatic plants in marshy districts, or underneath the floors of outbuildings.
It has a peculiar kind of hopping gait; and is mainly diurnal, in accordance with which habit its eyes are protected by lashes.
They prey upon every kind of arboreal animal - birds, tree-frogs, tree-lizards, &c. All seem to be diurnal, and the larger kinds attain to a length of about 4 ft.
On account of the high specific heat of sea-water the diurnal range of temperature at the surface is very small.
One of the best indications of actual winter weather, as apart from the arrival of winter by the calendar, is the development of cyclonic disturbances of such strength that the change frcm their warm, sirocco-like southerly inflow hi front of their centre, to the cold wave of their rear produces lion-periodic temperature changes strong enough to overcome the weakened diurnal temperature changes of the cold season, a relation which practically never occurs in summer time.
The gundi is a diurnal species, inhabiting rocky districts, and having habits very similar to those of a jerboa.
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.
The somewhat remarkable resemblance between the diurnal variation for the two elements, first remarked on by J.
So again, in the case of the Paris curves, the absolute value of the diurnal range in summer was much greater for the Eiffel Tower than for the Bureau Central, but the mean voltage was 2150 at the former station and only 134 at the latter.
It will be noticed that the difference between the greatest and least hourly values is, in all but three winter months, actually larger than the mean value of the potential gradient for the day; it bears to the range of the regular diurnal inequality a ratio varying from 2.0 in May to 3.6 in November.
Of all the periods marked out by the motions of the celestial bodies, the most conspicuous, and the most intimately connected with the affairs of mankind, are the solar day, which is distinguished by the diurnal revolution of the earth and the alternation of light and darkness, and the solar year, which completes the circle of the seasons.
The regularity of their diurnal revolutions could not escape notice, and a good deal was known 2000 years ago about the motions of the sun and moon and planets among the stars.
He attained correct views as to the character of centrifugal force in connexion with Galileo's theory; and, when the fact of the variation of gravity (Galileo's acceleration) in different latitudes first became known from the results of pendulum experiments, he at once perceived the possibility of connecting such a variation with the fact of the earth's diurnal rotation relatively to the stars.
diurnal variations cease to be sensible at a depth of 2 or 3 meters.
and intended to eliminate irregular changes, but they also to some extent eliminate regular changes if the hours of maxima and minima or the character of the diurnal variation alter throughout the year.
In habits some of the species are nocturnal and others diurnal; but all subsist on a mixed diet, which includes birds, reptiles, eggs, insects and fruits.
to c 1, vary much, then a diurnal inequality derived from a whole year, or from a season composed of several months, represents a mean curve arising from the superposition of a number of curves, which differ in shape and in the positions of their maxima and minima.
Annual and Diurnal Variations.-At Wolfenbi ttel, Elster and Geitel found A vary but little with the season.
A more considerable defect is due to the earth having a diurnal rotation relative to a Newtonian base, and this is never wholly ignored.
Take a base attached to the centre of the earth, but without this diurnal rotation.
Practically clocks are regulated by reference to the diurnal rotation of the earth relatively to the stars, which affords a measurement on the repetition principle agreeing with other methods, but more accurate than that given by any existing clock.
This type of colouring is also found in genera of quite distinct sub-families of butterflies, namely in Danainae and Pierinae, as well as in some diurnal moths, all of which occur in the same district as the Ithomiinae.
The climate, influenced by the high elevation, is characterized by long and severe winters and short summers with great diurnal extremes of temperature.
The most important unofficial contemporary works are the Histories of John Knox, Bishop John Lesley, George Buchanan, and Robert Lindsay of Pitscottie; the Diurnal of Remarkable Occurrents from the death of James IV.
4, showing the propagation of temperature waves due to diurnal variations in the temperature of the surface.
For instance, the velocity of propagation of a wave having a period of a day is nearly twenty times as great as that of a wave with a period of one year; but on the other hand the penetration of the diurnal wave is nearly twenty times less, and the shorter waves die out more rapidly.
0393 44 9 74 5 95.9 These figures are not wholly free from uncertainties, arising from true diurnal and annual variations in the frequency, but they give a good general idea of the influence of twilight.
Diurnal Variation.-The apparent daily period at most stations is largely determined by the influence of daylight on the visibility.
It is only during winter and in high latitudes that we can hope to ascertain anything directly as to the real diurnal variation of the causes whose influence is visible at night as aurora.
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).
- Diurnal Variation.
The preceding remarks relate to auroras as a whole; the different forms differ considerably in their diurnal variation.
points changes rapidly with change of latitude and longitude, and has a large diurnal variation.
The water-rat is perhaps the most often seen of all English mammals, owing to its diurnal habits.
In Quito the mean annual temperature is 58.8°, the diurnal variation 10°, the annual maximum 70°, and the annual minimum 45°.
This construction assumes that the sun describes daily a small circle about the pole of the celestial sphere, and ignores any diurnal variation in the declination.
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.
the great range of the diurnal variation of barometric pressure during the afternoon hours, - which is the more striking, since at Rurki, Lahore, and other stations near the foot of the Western Himalayas this range is less than in the open plains.
On the north, the Himalaya range and the plateau of Afghanistan shut it off from the climate of central Asia, and give it a continental climate, the characteristics of which are the prevalence of land winds, great dryness of the air, large diurnal range of temperature, and little or no precipitation.
On the south the ocean gives it an oceanic climate, the chief features of which are great uniformity of temperature, small diurnal range of temperature, great dampness of the air, and more or less frequent rain.
Where accurate differential observations or photographs involving other than instantaneous exposures have to be made, the additional condition is required that the optical axis of the telescope shall accurately and automatically follow the object under observation in spite of the apparent diurnal motion of the heavens, or in some cases even of the apparent motion of the object relative to neighbouring fixed stars.
Thus one important attribute of an equatorially mounted telescope that, if it is directed to any fixed star, it will follow the diurnal motion of that star from rising to setting by rotation of the polar axis only.
The difficulty is that the automatic motion of a single mirror capable of reflecting the rays of any star continuously along the axis of a fixed horizontal telescope, requires a rather complex mechanism owing to the variation of the angle of reflexion with the diurnal motion.
There are farther inconveniences in the use of such a telescope, viz., that the image undergoes a diurnal rotation about the axis of the horizontal telescope, so that, unless the sensitive plate is also rotated by clockwork, it is impossible to obtain sharp photographs with any but instantaneous exposures.
Also, if the axis is made to revolve at half the apparent diurnal motion of the stars, the image of the celestial sphere, viewed by reflection from such a moving mirror, will appear at rest at every point - hence the name coelostat applied to the apparatus.
The results were, however, always untrustworthy owing to annual and diurnal changes in the instrument.
There are brisk diurnal sea-breezes, and seasonal trades and counter-trades.
Diurnal currents of wind, which are established from the plains to the mountains during the day, and from the hills to the plains during the night, are impqrtant agents in distributing the rainfall.
The first really adequate determinations of solar parallax were those of Sir David Gill, measured by inference from the apparent diurnal shift of Mars among the stars as the earth turned diurnally upon its axis; the observations were made at the island of Ascension in 1878.
But, apart from the diurnal fluctuations of consumption which may be equalized by local " service reservoirs," uniform distribution of supply throughout twelve months is rarely what we require; and to represent the demand in most towns correctly, we should increase the angle of this line to the horizontal during the summer and diminish it during the winter months, as indicated by the dotted lines b b.
In both the desert of Gobi and in the desert of Lop a diurnal range of 44° has been observed.
When at the pole his zenith coincides with the celestial pole, and as the earth revolves on its axis, the heavenly bodies perform their apparent diurnal revolutions in horizontal circles round the zenith.
As he travels South, his zenith moves along the celestial sphere, and the circles of diurnal rotation become oblique to the horizon.
The circles of diurnal revolution again become oblique.
Finally, at the south pole the circles of diurnal revolution are again apparently horizontal, but are described in a direction apparently (but not really) the reverse of that near the north pole.
The other two systems, including the vernal equinox, are fixed on the celestial sphere, and so seem to us to perform a diurnal revolution from east towards west.
Here we have to make a distinction of fundamental importance between the diurnal motions of the sun and of the stars.
In astronomical practice is introduced a day, termed " sidereal," determined, not by the diurnal revolution of the sun, but of the stars.
We determine the apparent position of an object near the pole on the celestial sphere at any moment, and again at another moment, twelve hours later, when, by the diurnal motion, it has made half a revolution.
The unceasing diurnal motion of the image of any heavenly body relative to the cross threads of a telescope makes a direct accurate measure of any co-ordinate except the declination almost impossible.
The uniform speed of the diurnal motion is 15° per hour.
By revolving on this axis it follows a star in its diurnal motion, so that the star is kept in the field of view notwithstanding that motion.
Cassini, moreover, set up an altazimuth in 1678, and employed from about 1682 a " parallactic machine," provided with clockwork to enable it to follow the diurnal motion.
On the 24th of February 1616 the consulting theologians of the Holy Office characterized the two propositions - that the sun is immovable in the centre of the world, and that the earth has a diurnal motion of rotation - the first as "absurd in philosophy, and formally heretical, because expressly contrary to Holy Scripture," and the second as "open to the same censure in philosophy, and at least erroneous as to faith."
His last telescopic discovery - that of the moon's diurnal and monthly librations - was made in 1637, only a few months before his eyes were for ever closed in hopeless blindness.
The transformation from apparent to topocentric consists of allowing for diurnal aberration.
The regular diurnal, seasonal and solar cycle variations were then removed from the data by substracting from these the quiet standard value.
diurnal variability of solar input, or the annual or seasonal variation of heating.
mainly diurnal, with a maximum lifespan of 18 months.
They are predominantly diurnal (daytime) and feed on a variety of heathland plants.
Nocturnal intake rates were higher than diurnal intake rates owing to the consumption of more large earthworms at night.
epileptic encephalopathies show marked diurnal variation in seizure manifestation and electrographic activity.
interpolated directly from station time-series: precipitation, mean temperature and diurnal temperature range.
Chart 2 is a diurnal nativity with the Sun in Aries.
Her slow steady plod is provided by the diurnal movement of the night sky.
The last group in the diurnal raptors is the true falcons.
In contrast diurnal species have a tau of greater than 24 hours.
Kishimoto H, Hama Y. The level and diurnal rhythm of plasma tryptophan and tyrosine in manic-depressive patients.
In general there is far more diurnal and altitude related temperature variation than seasonal.
opposed by the leakage through imperfect insulation, or natural dissipation, and this may introduce a fictitious element into the apparent annual or diurnal variation.
gives the mean diurnal variation for the whole year at a number of stations arranged in order of latitude, the mean from the 24 hourly values being taken as loo.
It presents a remarkable resemblance to the adjacent curve, which gives the diurnal variation at mid-winter at the Bureau Central.
The alteration that takes place in the regular diurnal inequality throughout the year is best seen by analysing it into a Fourier series of the type c 1 sin (t+ a l) +c2 sin (2t+ a 2)+c 3 sin (3t+a3)+c4 sin (4t+a 4)+..
and I P.M., and in absence of information as to the diurnal variation it is impossible to say how much this influences the results.
Diurnal Variation.-At Karasjok Simpson found the mean values of I + and I_ throughout the whole year much the same between noon and I P.M.
At KremsmunsterZolss (41) finds a considerable similarity between the diurnal variations in q and in the potential gradient, the hours of the forenoon and afternoon maxima being nearly the same in the two cases.
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.
For, on account of the diurnal motion, the direction of the axis of the telescope when pointed to a star is always changing, so that, to follow a star with an altazimuth mounting, the observer requires to move continuously the two handles which give slow motion in altitude and azimuth.
Now direct the telescope to a star near the equator and so that the star's image in its diurnal motion shall pass across the intersection of the two webs which mark the axis of rotation of the micrometer box.
Then, as the diurnal motion causes the star-image to travel away from the axis of rotation, the micrometer box is rotated till the image of the star when at a considerable distance from the axis is bisected by the position-web.
The micrometer is now clamped in position-angle by the clamp C, the star again brought back to the axis, and delicate adjustment given in position-angle by the slow-motion screw M, till the star-image remains bisected whilst it traverses the whole length of the position-web by the diurnal motion only.
5) the eyepiece can be made to follow the star for a considerable distance along a position-web parallel to the screw, the bisection of the web by a star moving by the diurnal motion at right angles to the micrometer screw can only be followed for a limited distance, viz.
In measuring differences of declination, where the stars are brought up by the diurnal motion, this precaution cannot be adopted, because it is necessary always to bisect the preceding star with the fixed web.
The climate is healthy; owing to the elevated situation it is somewhat cold, and is liable to sudden diurnal and seasonal changes; the temperature in January sometimes falls to 4Ã‚° F.
(those relating to the diurnal birds-of-prey and the Cichlomorphae, or forms related to the thrushes) he found himself under the necessity of revising and modifying in the course of 1874, in as many communications to the Swedish Academy of Sciences (K.
HARPY, a large diurnal bird of prey, so named after the mythological monster of the classical poets (see Harpies), - the Thrasaetus harpyia of modern ornithologists - an inhabitant of the warmer parts of America from Southern Mexico to Brazil.
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.
The island regions of the Pacific are everywhere characterized by uniform high air-temperatures; the mean annual range varies from 1Ã‚° to 9Ã‚° F., with extremes of 24Ã‚° to 27Ã‚°, and the diurnal range from 9Ã‚° to 16Ã‚°.
In Quito the mean annual temperature is 58.8Ã‚°, the diurnal variation 10Ã‚°, the annual maximum 70Ã‚°, and the annual minimum 45Ã‚°.
The regular variations in pressure of the air indicated by the barometer and the annual and diurnal oscillations are as well marked in the Himalaya as elsewhere, but the amount of vapour held in suspension diminishes so rapidly with the altitude that not more than one-sixth (sometimes only one-tenth) of that observed at the foot of the mountains is found at the greatest heights.
In both the desert of Gobi and in the desert of Lop a diurnal range of 44Ã‚° has been observed.
The uniform speed of the diurnal motion is 15Ã‚° per hour.
These efforts have been very effective in removing the influence of the diurnal cycle from pulsation period measurements.
All general exemptions to display or sell diurnal birds of prey were revoked with effect from 31 March 1998.
Joyce 's Nighttown is most certainly the shadow-side of his diurnal Dublin, in which the taboos that are broken explicitly include the linguistic.
It can be nocturnal (occurring at night) or diurnal (occurring during the day).
Some children have both nocturnal and diurnal enuresis.
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