Who knows but if our instruments were delicate enough we might detect an undulation in the crust of the earth?
He world- sees throughout all the chaos of irregular crust-forms the ridges and recurrence of a certain harmony, a succession of folds or hollows.
The distribution of the mass of the atmosphere over the surface of the earth is also controlled by the relief of the crust, its greater or lesser density at the surface corresponding to the lesser or greater elevation of the surface.
The distinctive task of geography as a science is to investigate the control exercised by the crust-forms directly or indirectly upon the various mobile distributions.
The actual position of sea-level lies so near the summit of the crust-heap that the varied relief of the upper portion leads to the formation of a complicated coast- The con- line and a great number of detached portions of land.
Geologically, Syria belongs to two distinct regions of the earth's crust, the northern and smaller portion lying within the great belt of folding of southern Europe and central Asia, and the southern and larger portion belonging to the Indo-African area, which, though often faulted, is usually free from crumpling.
In skimming the crust from the surface of the lead some unalloyed lead is also drawn off, and has to be separated by an additional operation (liquation), as, running lower in silver than the crust, it would otherwise reduce its silver content and increase the amount of lead to be cupelled.
The retort is pear-shaped, and holds1000-1500lb of charge, consisting of liquated crust mixed with 1-3% of charcoal.
Pre-Darwinian zoologists had been aware of the class of facts thus interpreted by Fritz Muller, but the authoritative view on the subject had been that there is a parallelism between (a) the series of forms which occur in individual development, (b) the series of existing forms from lower to higher, and (c) the series of forms which succeed 'one another in the strata of the earth's crust, whilst an explanation of this parallelism was either not attempted, or was illusively offered in the shape of a doctrine of harmony of plan in creation.
In these respects they contrast with the great oceans which owe their origin to the most extensive and the profoundest depressions of the crust, date back at least to Mesozoic times, and have perhaps remained permanently in their present position from still remoter ages.
Recent pendulum observations have shown that it is incorrect to assume a uniform density of 2.6 in the elevated part of the earth's crust, that on the contrary there are great local differences in density, the most important being a confirmation of Airy's discovery that there is a marked deficiency of mass under high mountains and a marked excess under the bed of the ocean.
In the Red Sea the " Pola " expedition discovered a calcareous .00ze similar to that of the Mediterranean, and the formation of a stony crust by precipitation of calcium and magnesium carbonates may be recognized as giving origin to a recent dolomite.
From the obvious rarity of true abysmal rocks in the continental area Sir John Murray deduces the permanence of the oceans, which he holds have always remained upon those portions of the earth's crust which they occupy now, and both J.
The sea-worn amber has lost its crust, but has often acquired a dull rough surface by rolling in sand.
The fundamental basis of geography is the vertical relief of the earth's crust, which controls all mobile distributions.
The primary distinction of the forms of the crust is that between elevations and depressions.
So far only is it possible to speak with certainty, but it is permissible to take a few steps into the twilight of dawning knowledge and indicate the chief subdivisions which are likely to be established in the great crust-hollow and the great crust-heap. The boundary between these should obviously be the mean surface of the sphere.
He showed that an imaginary spheroidal shell, concentric with the earth and cutting the slope between the elevated and depressed areas at the contour-line of 1700 fathoms, would not only leave above it a volume of the crust equal to the volume of the hollow left below it, but would also divide the surface of the earth so that the area of the elevated region was equal to that of the depressed region.6 A similar observation was made almost simultaneously by Romieux, 7 who further speculated on the equilibrium between the weight of the elevated land mass and that of the total Areas of waters of the ocean, and deduced some interesting relathe cru st tions between them.
Second great series of crust waves from north to south, giving rise by their interference to six great elevated masses (the continents), arranged in three groups, each consisting of a northern and a southern member separated by a minor depression.
Suess,' who points out that the plan of the earth is the result of Suess two movements of the crust - one, subsidence over theory.
This theory of crust blocks dropped by subsidence is opposed to Lapworth's theory of vast crust-folds, but geology is the science which has to decide between them.
Logical, political and commercial development of the subject runs the determining control exercised by crust forms acting directly or indirectly on mobile distributions; and this is the essential principle of geography.
The common monoclinic variety is obtained by allowing a crust to form over molten sulphur by partially cooling it, and then breaking the crust and pouring off the still liquid portion, whereupon the interior of the vessel will be found coated with long needles of this variety.
Many of them are fault block mountains, the crust having been broken and the blocks tilted so that there is a steep face on one side and a gentle slope on the other.
This is a region of innumerable faulted crust blocks, the elevated ones creating the N.
Although for the purposes of geographical nomenclature, boundaries formed by a coast-line - that is, by depressions of the earth's solid crust below the ocean level - are most easily recog- Political nized and are of special convenience; and although such divisions.
Many of the freshwater algae which form a mere crust, such as Palmella cruenta, may be placed in a vessel of water, where after a time they float like a scum, the earthy matter settling down to the bottom, and may then be mounted by slipping a piece of mica under them and allowing it to dry.
A few shallow salt lakes are filled by rain water, but they dry up on the setting in of the hot weather, leaving a thick crust of salt on their beds, which is used for commercial and domestic purposes.
During the winter the smaller tributaries freeze to the bottom, and about 1st January Lake Baikal becomes covered with a solid crust of ice capable of bearing files of loaded sledges.
Of zinc, all the gold and copper and some silver and lead will be alloyed with the zinc to a so-called gold - or copper - crust, and the residual lead saturated with zinc. By removing from the surface of the lead this first crust and working it up separately (liquating, retorting and cupelling), dore silver is obtained.
In the puszta are numerous small lakes, named generally Feher To or White Lakes, because they evaporate in the summer leaving a white crust of soda on their bed.
Pure crystalline calcium carbide yields 5.8 cubic feet of acetylene per pound at ordinary temperatures, but the carbide as sold commercially, being a mixture of the pure crystalline material with the crust which in the electric furnace surrounds the ingot, yields at the best 5 cubic feet of gas per pound under proper conditions of generation.
They owe their origin to depressions of the earth's crust of no very wide extent and not running very far into the continental mass, and geologically they are of recent age and still subject to change.