Shrinkage

“ Try to break either warp or woof threads. Place the two thumbs together and press down on the cloth which should be held firmly in the hands. Try both sets of threads. Sometimes a weak warp or woof can be discovered.
Tests for shrinkage. Barbara Oakes had a white cotton dress last year which never seemed to stop shrinking. Sometimes we can test materials for shrinkage. Measure width and length of sample to be tested. Wash it in hot water and soap. Dry and measure again. Is it narrower and shorter? In planning for cotton or woolen garments allowance should be made for shrinkage.
[284] ”

“ The shrinkage which all clays undergo on drying and when heated is another important characteristic. It is due to the fact that as water is removed the solid particles approach closer to each other, the volume of the whole mass being thereby reduced. ”

“ If we look then, upon the spherical form of the cell as its true condition of symmetry and of equi­lib­rium, we see that what we call its normal appearance is just one of many intermediate phases of shrinkage, brought about by the abstraction of fluid from its interior as the result of an osmotic pressure greater outside than inside the cell, and where the shrinkage of volume is not kept pace with by a contraction of the surface-area. In the case of the blood-corpuscle, the shrinkage is of no great amount, and the resulting deformation is symmetrical ”

“ One set may be actually rising relative to the center of the earth, and the other sinking, while the ocean-level is stationary, or nearly so. This is the way in which we are accustomed to interpret them. A general shrinkage of the earth, however, is probably going on, carrying down land-surface and sea-surface. It has been urged by Suess [239] that the general shrinkage is so great that the local upward warpings and foldings never equal it, and that the real movements are all downward, though in different degrees. ”

“ The shrinkage is more apparent, more lasting, and of more consequence to the architect, builder, or owner than the slight expansion which takes place, as, although the amount of moisture contained in wood varies with the climate conditions, the consequence of dampness or moisture on good timber used in houses only makes itself apparent by the occasional jamming of a door or window in wet or damp weather. ”

“ Thick walled cells shrink more than thin ones and summer wood more than spring wood. Cell walls do not shrink lengthwise and since the length of a cell is often a hundred or more times as great as its diameter the small shrinkage in the thickness of the cell walls at A and B, in Fig. 199, is not sufficient to make any noticeable change in the length of the timber.
Fig. 199.
Fig. 200.
Since the cells of the pith or medullary rays extend at [123] right angles to the main body, Fig. 200, their smaller shrinkage along the radius of the log opposes the shrinkage of the longitudinal fibers. ”

“ There is an enormous difference in the total amount of shrinkage of different species of wood, varying from a shrinkage of only 7 per cent in volume, based on the green dimensions, in the case of some of the cedars to nearly 50 per cent in the case of some species of eucalyptus. ”

“ Shrinkage involves a process whereby the priming, roughstuff, color, varnish, etc., apparently goes in while the grain of the wood goes out. Graining out is often due to a priming coat that is not given adequate time to dry hard and firm. This soft layer of rather slow drying pigment, if sealed from contact with the air prematurely, is a powerful inducement to grain showing. ”

“ A very important factor in the value of a fabric is the shrinkage. The extent of this may be determined by pouring hot water over a sample of about twelve by twenty inches, and leaving the fabric immersed over night, then drying it at a moderate temperature without stretching. ”

“ As the work progresses the clay may be allowed to harden and consolidate, but not to dry; if allowed to dry entirely the model may be considered ruined, as the shrinkage of the clay around the support results in fissures and fractures that cannot be repaired. ”

“ Owing to the great difference of cells in shape, size, and thickness of walls, and still more in their arrangement, shrinkage is not uniform in any kind of wood. This irregularity produces strains, which grow with the difference between adjoining cells and are greatest at the pith rays. These strains cause warping and checking, but exist even where no outward signs are visible. They are greater if the wood is dried rapidly than if dried slowly, but can never be entirely avoided. ”

“ An entirely different kind of shrinkage-crack is that which occurs in certain carbonised and flattened plants, and which sometimes communicates to them a marvellous resemblance to the netted under surface of an exogenous leaf. Flattened stems of plants and layers of cortical matter, when carbonised, shrink in such a manner as to produce minute reticulated cracks. These become filled with mineral matter before the coaly substance has been completely consolidated. A further compression occurs, causing the coaly substance to collapse, leaving the little veins of harder mineral matter projecting. ”

“ Our shingles are free from the many accidents to which slate roofs are liable, such as cracking from shrinkage of wood-work to which they are attached; breaking, caused by necessary repairs to the valleys or chimneys ”

“ When the specimen has been placed on its pedestal, it then remains to shape the legs, neck, and feet, which the soft clay underneath renders quite easy. Folds and wrinkles in the skin must be exaggerated, to provide for what is sure to disappear by shrinkage in drying. ”

“ The larger the specimen the thicker is the skin, and consequently the harder and more unyielding should be the material it rests upon. Do not make a manikin with hoop iron and burlap, and a little loose filling between that and the skin, for specimens so mounted nearly always come to grief. If you stuff a skin with straw, excelsior, or tow, pack the filling in a solid mass, for with the lapse of time all such materials are bound to shrink, no matter how hard you make them at first. The shrinkage of straw is often remarkable and highly disastrous. ”

“ The ascent at first appears easy, but a thin layer of ashes, formed into a crust by the action of rain and moisture, is not strong enough to sustain a man's weight. At every step my feet crushed through the outer covering and I sank at first ankle-deep and later on knee-deep into a soft, almost impalpable dust which arose in clouds and nearly suffocated me. ”

“ When seen for the first time in its natural haunt one naturally wonders what the moving mass may be. Crawling sluggishly over incrusted stones, or remaining perfectly still in a muddy puddle that has been exposed by overturning a stone, it looks like a little mound of mud itself, about four or five inches long, and its general colour and surface so closely resembles that of its surroundings that an inexperienced collector may never even suspect that the mass is a living animal form. ”

“ And a second that is more hard and close, into which the water can very little, or not at all penetrate, this therefore retaining always very neer the same dimensions, and the other stretching and shrinking, according as there is more or less moisture or water in its pores, by reason of the make and shape of the parts, the whole body must necessarily unwreath and wreath it self. ”

“ There is considerable distortion of the clay, resulting from combined shearing and tensile stress, above each of the steps of rock, and reaching its maximum at and above the highest rise ab, where it has proved sufficient to produce a dangerous line of weakness ac, the tension at a either causing actual rupture, or such increased porosity as to permit of percolation capable of keeping open the wound. In such cases as are shown in figs. 8 and 9 the growth of the sand vein is not vertical, but inclined towards the plane of maximum shearing strain. Fig. ”

“ Just where the waves curl beyond such a point you may discern a multitude of blackened, snaggy shapes protruding above the water,—some high enough to resemble ruined chimneys, others bearing a startling likeness to enormous skeleton-feet and skeleton-hands,—with crustaceous white growths clinging to them here and there like remnants of integument. ”

“ In the case of the earth, the hard stratified crust had to adapt itself to the shrunken diameter of the once much hotter globe. This tangential action is illustrated in our own persons, when age causes the body to shrink in bulk, while the skin, which does not shrink to the same extent, has to accommodate itself to the shrunken interior, and so forms wrinkles—the wrinkles of age. This theory opens up a chapter in geology and physiology well worthy of consideration. ”

“ When the whole earth got cool in the first hours of the world's morning, the diminution of the volume of the earth produced a state of dislocation in its upper crust, followed by ruptures, crevasses and fissures. The passage was a fissure of this kind, through which, ages ago, had flowed the eruptive granite. The thousand windings and turnings formed an inextricable labyrinth through the ancient soil. As we descended, successions of layers composing the primitive soil appeared with the utmost fidelity of detail. ”

“ We declare the stone to be the cause of the breaking of the glass, why? Because we observe the fall of the stone, and on reproducing the same conditions, the same results follow; fall of stone, then breaking of glass. Furthermore, increasing the weight of the stone, more layers of glass are broken, on decreasing the weight of the stone fewer layers are broken, variations in the consequent depend on the variations of the antecedent. ”

“ An idea of it may be imparted by taking a dozen shingles and laying them on a level, as you would upon a roof, with the butts lapping a couple of inches only. Consider this the bed of a river with the water flowing over it from the thin end of the shingles, the butts being from three or four feet to ten in thickness. At each butt, or where the rock breaks abruptly, there is a scarcely perceptible motion of the water; immediately beneath is a deep hole, growing shallower as the next butt is reached ”

“ Now the adhesive force of water to itself, and to other substances, may be estimated from the weight of it necessary to separate a drop, which adheres, while growing, till it has weight enough to force the separation and break the drop off. ”

“ This defect may be due to violent heat from certain quarters of the sky, pouring into the open pores in too great proportion to admit of a mixture suited to the natural temperament of the body in question. Again, if too much mois­ture enters the channels of a body, and thus introduces dispropor­tion, the other elements, adulterated by the liquid, are impaired, and the virtues of the mixture dissolved. This defect, in turn, may arise from the cooling properties of moist winds and breezes blowing upon the body. ”

“ When a cavity is bored into, it may be rammed full of clay, and the boring continued through the clay; or if sufficient depth has been obtained, the charge may be placed upon the clay, which will prevent the wasteful dissipation of the gases. ”

“ For where a body has been burnt the grass will be darker in hue, more luxuriant, and taller than that surrounding it, and will not lose these characteristics for a long time, the fat and grease of the body sinking down to the roots of the grass and causing the above results. If the spot is on a hill, or in a wild place where the vegetation is very luxuriant, then you must look for a growth about the height of a man. ”

“ Faces display random flaking. Secondary flaking of short, broad nature appears, followed by fine retouch, as from pressure flaking, along the edges. The basal thinning is usually short, broad and shallow, but in rare examples it may extend approximately the length of the hafting area. ”

“ The gradual cooling must have exerted continued pressure, and the wrinkles have become larger. [Pg 127] It is not likely that new wrinkles would be formed as long as the old ones would crumple and draw up into narrower, steeper slopes, in response to the lateral crushing. ”

“ FRACTURES AND DISLOCATIONS OF THE CRUST Considering the immense stresses to which the rocks of the crust are subjected, it is not surprising to find that they often yield by fracture, like brittle bodies, instead of by folding and flowing, like plastic solids. Whether rocks bend or break depends on the character and condition of the rocks, the load of overlying rocks which they bear, and the amount of the force and the slowness with which it is applied. ”

“ FORMATION OF INTERSPACE and Examples of the Enclosed Patterns.
The ridges are said to be first discernible in the fourth month of fœtal life, and fully formed by the sixth. In babies and children the delicacy of the ridges is proportionate to the smallness of their stature. They grow simultaneously with the general growth of the body, and continue to be sharply defined until old age has set in, when an incipient disintegration of the texture of the skin spoils, and may largely obliterate them, as in the finger prints on the title-page. ”

“ The cause of their sinking, therefore, is not death of the creatures, but weight of their shells. The thickening consists in a deposit of calcareous matter upon the outside of the proper wall after the creatures' full growth, which not only increases the weight, but alters the contour of the shell. ”