Advanced PhysiographyLongmans, Green, and Company, 1893 - 358 pages |
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absorption angle angular appears astronomical atmosphere axis bright lines called carbon causes celestial sphere centre changes chemical chromosphere circle colour comets dark lines density diameter direction disc distance earth ecliptic equator equatorial equinox fixed stars formed Fraunhofer lines give gravity heat heavenly bodies hemisphere Hence horizon hydrogen increase iron Jupiter known latitude length lens light longitude lunar magnetic Mars mass mean measured meridian metallic meteorites meteors miles minerals moon moon's motion move nearly nebula needle northern hemisphere observed ocean orbit parallax parallel particles passing perihelion period photosphere planet point of Aries pole position precession pressure prism produced proper motion radius rays reflected refraction revolution revolving right ascension rocks rotation round the sun satellites seen sidereal sidereal day sodium solar spectrum spectra spectroscope spots sun's telescope temperature terrestrial tides tion Uranus vapour velocity Venus vernier vertical winds zenith
Popular passages
Page 241 - Newton generalized the law of attraction into a statement that every particle of matter in the universe attracts every other particle with a force which varies directly as the product of their masses and inversely as the square of the distance between them; and he thence deduced the law of attraction for spherical shells of constant density.
Page 204 - Ascension, and the interval between the departure of any meridian from the mean Sun and its succeeding return to it is the duration of the mean solar day. Clocks and chronometers are adjusted to mean solar time ; so that a complete revolution (through 24 hours) of the hour hand of...
Page 307 - ... million years ago, or we should not have so much as the least observed underground increment of temperature. That is to say, I conclude that Leibnitz's epoch of emergence of the consistentior status was probably between those dates.
Page 265 - In whatever direction a body moves on the surface of the earth, there is a force arising from the earth's rotation, which deflects it to the right, in the northern hemisphere, but to the left, in the southern.
Page 132 - Calorie is the amount of heat required to raise the temperature of one kilogram of water one degree Centigrade. It is therefore one thousand times as large as the small calorie. The British Thermal Unit (BTU) is the heat required to raise the temperature of one pound of water one degree Fahrenheit.
Page 329 - Boron has only two strong lines. The lines of bismuth are compound and too diffuse. Therefore even in the case of these fifteen elements there is little evidence that they are really absent from the sun. It follows that if the whole earth were heated to the temperature of the sun, its spectrum would resemble very closely the solar spectrum. Rowland has not found any lines common to several elements, and in the case of some accidental coincidences, more accurate investigation reveals some slight difference...
Page 305 - Laplace in a single hypothesis, involving only one assumption in addition to that of original fluidity and the law of gravitation.* This assumption relates to the compressibility of matter and asserts that the ratio of the increment of pressure to the increment of density is proportional to the density. Many interesting and striking conclusions follow readily from this hypothesis, but the most interesting and important are those relative to density and pressure, especially the latter, whose dominance...
Page 133 - The essential principle of the explanation is this ; at some period of time, long past, the sun's initial heat was generated by the collision of pieces of matter gravitationally attracted together from distant space to build up his present mass ; and shrinkage due to cooling gives, through the work done by the mutual gravitation of all parts of the shrinking mass, the vast heat-storage capacity in virtue of which the cooling has been, and continues to be, so slow.
Page 307 - ... of uniform temperature, and draws therefrom certain striking limitations on geologic time. Many geologists were startled by these limitations and geologic thought and opinion have since been widely influenced by them. It will be of interest therefore to state a little more fully and clearly the grounds from which his arguments proceed. Conceive a sphere having a uniform temperature initially, to cool in a medium which instantly dissipates all heat brought by conduction to its surface, thus keeping...