Elements of Technology: Taken Chiefly from a Course of Lectures Delivered at Cambridge, on the Application of the Sciences to the Useful Arts : Now Published for the Use of Seminaries and Students

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Hilliard, Gray, Little and Wilkins, 1831 - 521 sivua
 

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Sivu ii - District Clerk's Office. BE IT REMEMBERED, that on the tenth day of August, AD 1829, in the fifty-fourth year of the Independence of the United States of America, JP Dabney, of the said district, has deposited in this office the title of a book, the right whereof he claims as author, in the words following, to wit...
Sivu 45 - The modulus of the elasticity of any substance is a column of the same substance, capable of producing a pressure on its base which is to the weight causing a certain degree of compression, as the length of the substance is to the diminution of its length.
Sivu 454 - Blue vat, in which white spots are left on a blue ground of cloth, is made by applying to these points a paste, composed of a solution of sulphate of copper and pipe-clay, and, after they are dried, immersing it, stretched on frames, for a definite number of minutes, in the yellowish-green vat, of one part of indigo, two of copperas, and two of lime, with water.
Sivu 466 - The basis of all enamels is, therefore, a transparent and fusible glass. The oxide of tin renders this of a beautiful white, the perfection of which is greater, when a small quantity of manganese is likewise added. If the oxide of tin be not sufficient to destroy the transparency of the mixture, it produces a semi-opaque glass, resembling the opal.
Sivu 368 - ... for several hours with the hands. It is then formed into a flat surface, with several concentric folds, which are still further compacted in order to make the brim, and the circular part of the crown, and forced on a block, which serves as a mould for the cylindrical part. The nap, or outer portion of the fur, is raised with a fine wire brush, and the hat is subsequently dyed, and stiffened on the inside with glue. An attempt has been made, and at one time excited considerable expectation in...
Sivu 271 - B which are shut up, will be pressed outwards by a force equal to the weight of a column of water whose height is TT, and whose area is the area of the apertures. Every part of the tube AB sustains a similar pressure; but as these pressures are balanced by equal and opposite pressures, the arm AB is at rest. By opening the aperture at A, however, the pressure at that place is removed, and consequently...
Sivu 488 - From reasoning a priori, it would seem that no treatment would be so effectual in getting rid of the greatest quantity of sap, as to girdle the tree, by cutting away a ring of alburnum, in the early part of summer, thus putting a stop to the further ascent of the sap, and then to suffer it to stand until the leaves should have expended, by their growth, or transpiration, all the fluid which could be extracted by them previously to the death of the tree.
Sivu 147 - STYLE. After the dismemberment of the Roman empire, the arts degenerated so far, that a custom became prevalent of erecting new buildings with the fragments of old ones, which were dilapidated and torn down for the purpose. This gave rise to an irregular style of building, which continued to be imitated, especially in Italy, during the dark ages. It consisted of Grecian and Roman details, combined under new forms, and piled up into structures wholly unlike the antique originals. Hence the names Greco-gothic...
Sivu 137 - ... intended as places of resort for the priests, rather than for the convening of assemblies within, were in general obscurely lighted. Their form was commonly that of an oblong square, having a colonnade without, and a walled cell within. The cell was usually without windows, receiving its light only from a door at the end, and sometimes from an opening in the roof. The part of the colonnade which formed the front portico, was called the pronaos, and that which formed the back part, the posticus.
Sivu 492 - States, the interstices between the timbers in various parts of the hull, are filled with dry salt. When this salt deliquesces, it fills the pores of the wood with a strong saline impregnation, but it has been said, in some cases, to render the inside of the vessel uncomfortably damp. If timber is immersed in a brine made of pure muriate of soda, without the bitter deliquescent salts, which sea water contains, the evil of dampness is avoided. A variety of other substances besides common salt, act...

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