Geomancy

“ It will be evident that an exact knowledge of the figure of the earth has an important bearing on any hypothesis of the internal constitution of our planet. Geodesy, that science that may be called surveying on a grand scale, and which takes for its bases of measurement at once the earth and the heavens, has not yet completed its work. ”

“ The remark is just: but although the dimensions of such a crust are, in truth, insignificant when compared to the entire globe, yet they are vast, and of magnificent extent in relation to man, and to the organic beings which people our globe. Referring to this standard of magnitude, the geologist may admire the ample limits of his domain, and admit, at the same time, that not only the exterior of the planet, but the entire earth, is but an atom in the midst of the countless worlds surveyed by the astronomer. ”

“ The basis of every extensive survey is an accurate triangulation, and the operations of geodesy consist in the measurement, by theodolites, of the angles of the triangles; the measurement of one or more sides of these triangles on the ground; the determination by astronomical observations of the azimuth of the whole network of triangles; the determination of the actual position of the same on the surface of the earth by observations, first for latitude at some of the stations, and secondly for longitude ”

“ To these two-dimensioned geometers geodesies would possess many of the attributes of straight lines in ordinary space. If the surface to which the beings were confined were actually a plane, then the geometry would be the same as our geometry. They would find that only one straight line could be drawn between two points, that through a point only one parallel to a given line could be drawn, and that the ends of a line would never meet even though the line be prolonged to infinity.
We might also suppose that intelligent beings could exist on the surface of a sphere. ”

“ Questions in astronomy, such as those which Turrettine and the opponents of Galileo entertained, must be tried, we hold, not by a revelation never intended to teach astronomy, but by the findings of astronomic science. But how deal, I next ask, with the theologian who holds that geologic fact has been revealed to him? Geology is as thoroughly a physical science as either geography or astronomy. Its facts are equally capable of being educed and established by the unassisted human intellect. ”

“ Every man in full command of his senses knows that a level surface is a flat or horizontal one; but astronomers tell us that the true level is the curved surface of a globe! They know that man requires a level surface on which to live, so they give him one in name which is not one in fact! Since this is the best that astronomers, with their theoretical science, can do for their fellow creatures—deceive them—it is clear that things are not as they say they are; and, in short, it is a proof that Earth is not a globe. ”

“ But while thus culling freely from the dominions of other sciences, geology claims as its peculiar territory the rocky framework of the globe. In the materials composing that framework, their composition and arrangement, the processes of their formation, the changes which they have undergone, and the terrestrial revolutions to which they bear witness, lie the main data of geological history. It is the task of the geologist to group these elements in such a way that they may be made to yield up their evidence as to the march of events in the evolution of the planet. ”

“ None of these phenomena can be interpreted and accounted for without the aid of the geologist: without some knowledge of rocks and rock-structures, the origin of the earth’s surface-features is quite inexplicable. To give an adequate explanation of all the surface-features of a country in detail would of course require a profound study of Geology; but a general acquaintance only with its elementary facts is quite sufficient to enable us to form a reasonable and intelligent view of the cause and origin of the main features of the land as a whole. ”

“ At all the confines of his science, the transcendental geologist finds himself confronted with some of the most stupendous problems which have ever engaged the restless intellect of humanity. The origin and primæval constitution of the terrestrial globe, the laws of geologic action through long ages of vicissitude and development, the origin of life, the nature and source of the myriad complexities of living beings, the advent of man, possibly even the future history of the earth, are amongst the questions with which the geologist has to grapple in his higher capacity. ”

“ If the earth is a sphere then why could a map so draughted as truly to represent the surface of a sphere not be counted the most acceptable? This must have been the argument of those who especially applied themselves to the designing of maps suitable for a spherical surface, that is, for application to a globe ball. ”

“ It is now possible, with more or less confidence, to trace backward the history of every terrestrial area, to see how sea and land have there succeeded each other, how rivers and lakes have come and gone, how the crust of the earth has been ridged up at widely separated intervals, each movement determining some line of mountains or plains, how the boundaries of the oceans have shifted again and again in the past, and thus how, after so prolonged a series of revolutions, the present topography of each country, and of the globe as a whole, has been produced. ”

“ In like manner, when the geologist surveys the convexity of his own globe, he finds its solid covering composed of rocks and beds of all shapes and kinds, lying at every possible angle, occupying every possible position, and all of them, generally speaking, at the same distance from the earth’s centre. Every where we see what was deep brought into visible relation with what was superficial—what is old with what is new—what preceded life with what followed it. ”

“ Here again it is observable, not only that the instrument is found ready made, but that Nature is perpetually performing the process of measurement. Any fixed, erect object—a column, a dead palm, a pole, the angle of a building—serves for a gnomon; and it needs but to notice the changing position of the shadow it daily throws to make the first step in geometrical astronomy. ”

“ Even the earth itself is composed, as geologists tell us, of various strata, composed of different substances, and varying from one degree of density to another. If every part of our globe be regulated according to the received laws of gravity, and the relative density of matter, why do we find almost all over the world, light alluvial soil in the vallies and [55] plains; and on the tops of the highest mountains, the more heavy granite, and some of the heaviest substances that nature knows? ”

“ That phase which treats of the outer relations of the earth is Cosmic or Astronomic geology; that which treats of the constituent parts of the earth and its material is Geognosy, of which the most important branch is Petrology, the science of rocks. That branch which investigates the structural arrangement of the material, or “the architecture of the earth,” is Geotectonic, or Structural geology; while that which deals with the surface changes and topographic forms, that is, with the face of the earth, is Physiographic geology. ”

“ By methods, the history and description of which we have not here sufficient space to give, it has been proved that the earth is, in form, a globe, or more strictly an ellipsoid, slightly drawn in at the poles and swollen round the equator. The polar diameter is 7899 miles, and the equatorial diameter 7926 miles, the difference amounting to only 27 miles. Thus, for ordinary purposes, we may regard the earth as being a true sphere. ”

“ Geognosy is used by the French as synonymous to geology, but in English is generally understood to be synonymous to cosmogony; which is an inquiry, or rather a speculation, as to the original formation or creation of the world; hence geognosy has sometimes been called "speculative geology." In pursuing the examinations to which geology leads, we reason from facts, as is done in other branches of natural science. The strata of the crust of the earth, owing to the disturbed manner in which we now find them, are in a great measure open to our examination ”

“ But in physical and structural geology he took a very high place among living scientists. The thorough training and natural aptitude for structural and field geology made him a very shrewd judge of controversial questions in tectonics, and laid a secure foundation for his researches in geographical evolution and the origin of the earth’s surface features. As a geographer, interested especially in the larger problems of geographical configuration, he earned a world-wide reputation. ”

“ On their side, geometers, when measuring the size of the entire earth, avail themselves of the data furnished by the natural philosopher and astronomer; and the geographer on his part makes use of those of the geometer.
3. The heavens and the earth must be supposed to be divided each into five zones, and the celestial zones to possess the same names as those below. The motives for such a division into zones we have already detailed. These zones may be distinguished by circles drawn parallel to the equator, on either side of it. ”

“ We see then that the effect of the uneven distribution of matter in the crust of the earth is to produce small elevations and depressions on the mathematical surface which would be otherwise spheroidal. No geodesist can proceed far in his work without encountering the irregularities of the mathematical surface, and it is necessary that he should know how they affect his astronomical observations. ”

“ The recent progress of geognosy, that is to say, the more extended knowledge of the geognostic epochs characterized by differences of mineral formations, by the peculiarities and succession of the organisms contained within them, and by the position of the strata, whether uplifted or inclined horizontally, leads us, by means of the causal connection existing among all natural phenomena, to the distribution of solids and fluids into the continents and seas which constitute the upper crust of our planet. ”

“ A giant cognitive step bridged the immediacy of the surroundings-where magic forces were rumored to exist, waiting for humans to free them-and the notion of space. Geometry-which literally means to measure land-is relevant as a practical experience of human self-constitution that unites the concrete task at hand (surveying, building, decorating, observing the sky) and the generalization of distance. ”

“ Under dynamical geology are included important subdivisions, such as seismic geology, or the study of earthquakes, and vulcanology, or the study of volcanoes. Another large subject, glacial geology, belongs within the broad frontier common to both dynamical geology and physiography. A relatively new subdivision of geological science is orientational geology, which is concerned with the trend of earth features, and is closely related both to physiography and to dynamical and structural geology. ”

“ The figure of the earth, even on the ocean, is irregular, in consequence of the greater preponderance of land—and hence greater density—in the northern hemisphere. These irregularities are often very perplexing in making exact geodetic measurements. ”

“ All the facts in any part of nature shall be tabulated, and the results shall indicate the same security and benefit; so slight as to be hardly observable, and yet it is there. The sphere is flattened at the poles, and swelled at the equator; a form flowing necessarily from the fluid state, yet the form, the mathematician assures us, required to prevent the protuberances of the continent, or even of lesser mountains cast up at any time by earthquakes, from continually deranging the axis of the earth. ”

“ Geognosy certainly contains many facts, which cannot be explained, but by a change from dry land to the bottom of the sea, although our knowledge of them is still so imperfect, that we cannot hazard a probable conjecture respecting the numbers of these changes, whether they commence at the same or at different periods in the various quarters of the world, and whether they are local or universal. ”

“ Where the surface is spherical, the geodetic is always literally a “great circle,” a circle, that is to say, whose centre is the centre of the sphere. If instead of a sphere we be dealing with an ellipsoid, the geodetic becomes a variable figure, according to the position of our two points. {441} For obviously, if they lie in a line perpendicular to the long axis of the ellipsoid, the geodetic which connects them is a circle, also perpendicular to that axis ”

“ That craving for the grand and the sublime, that hungering after cataclysms and convulsions, that insatiable appetite for upheavals, and Titanic earth-throes, and all the mightier machinery of Nature, has done no little mischief to geology. Men have reasoned that gigantic results in the physical structure of the earth must have had equally gigantic causes operating in sublime conflict and in periodic paroxysms, now heaving a mountain chain to the clouds of heaven, now swallowing up a continent in the depths of the sea. ”

“ My dear sir, geometry deals with facts of space, space itself is taken as an ultimate datum. The work of geometry is not to ask what space is in itself, but what the relations are of spatial forms, space itself being postulated. ”

“ Geometers, as already stated, have demonstrated that, in the midst of all the fluctuations which can possibly take place in the elements of the orbits of the planets, by reason of their mutual attraction, the general balance of the parts of the system will always be preserved, and every departure from a mean state periodically compensated. But neither the researches of the physical astronomer, nor those of the geologist, give us any ground for regarding our system, or the globe we inhabit, as of eternal duration. ”