. Appleton's dictionary of machines, mechanics, engine-work, and engineering. sachusetts, and patented Au-gust 17, 1835 ; patent extended May 14, 1849. In the drawings, Fig. 3957 denotes a side ele-vation ; Fig. 3958, a vertical central same letters refer to like parts in eachfigure. A is the main bar; B, the nut fitted to ascrew, cut on the two opposite edges of themain bar; C, a strap, which passes around in agroove formed in the nut B, and is riveted tothe end of the slide-jaw D. The collar on theend of the nut B takes into a correspondinggroove in the slide D; E, the end of the
. Appleton's dictionary of machines, mechanics, engine-work, and engineering. sachusetts, and patented Au-gust 17, 1835 ; patent extended May 14, 1849. In the drawings, Fig. 3957 denotes a side ele-vation ; Fig. 3958, a vertical central same letters refer to like parts in eachfigure. A is the main bar; B, the nut fitted to ascrew, cut on the two opposite edges of themain bar; C, a strap, which passes around in agroove formed in the nut B, and is riveted tothe end of the slide-jaw D. The collar on theend of the nut B takes into a correspondinggroove in the slide D; E, the end of the mainbar, which forms the stationary jaw of thewrench; F, the handle. The nut is made tomove freely in the strap C, and, by turning it tothe right or left, the slide D is moved to any desired point on the main bar. The principal advantages possessed by this wrench are, its simplicity of construction and consequentcheapness—its compactness, durability, and strength ; the size of the main bar being duly proportionedto the power applied, as will be seen in the figure. ZINC, composition and use of. Zinc or Spelter has a crystalline texture, is brittle at ordinary tem-peratures, and of a bluish-white color: at 300°, it is both malleable and ductile, and at a white heatit is converted into vapor. When pure zinc is exposed to air and moisture, it acquires a dull color frompartial oxydizement; and great electric action takes place when it is in contact with copper, and thezinc decays in consequence. Its specific gravity is 7, and it has a great attraction for oxygen; theweight of a cubic foot is 439i pounds. Oxide of zinc is obtained by intensely heating the metal exposed to air; it takes fire at a red heat,if the air is freely admitted, burning with a very bright flame. Zinc 1 32 80 Oxygen 1 8 20 T 40 100 Sulphuret of zinc (blende) is found native, and is a brittle, soft metal, of a brown and black color ; itsprimitive form is a rhomboidal dodecahedron, and it is a most abun
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Keywords: ., bookcentury1800, booksubjectmechanicalengineering, bookyear1861
