Shackles are iron staples, which serve to receive the leather suspension braces of C spring carriages on the springs; they are also used for coupling springs together. Jacks are small windlasses, which serve to receive the ends of the leather suspension braces after passing round the backs of the springs. By means of a wrench or winch handle the jacks may be wound up or let down so as to lengthen or shorten the brace. Then we have the hinges, which are now concealed in the door pillar, effecting a great improvement in the appearance of the vehicle, though it necessitates a somewhat stouter pillar than would otherwise be necessary. To preserve the ironwork and steelwork of carriages from rusting, it is either painted or plated with some metal on which the oxygen of the air does not act. When it is wished to make it ornamental, carriage ironwork is plated, in which case it is first covered with a coat of tin laid on by means of a soldering iron, with rosin and a small portion of sal-ammoniac in order to promote union between the two metals. The tin being smoothed, a small portion of silver or brass, rolled exceedingly thin, is laid on, and by means of the soldering iron is made to adhere to the tin; more of the plating metal is then added to join the first by the edges, till the whole surface is covered. It is then burnished and polished by means of the proper tools. All articles of iron requiring to be covered with silver are treated in the same way; small articles of ornament in brass, which do not require strength, are cut in solid metal, as it is cheaper by the saving in labour; but for heavy articles, the weight of the metal would considerably enhance the price, supposing that strength were not required. Wheel nave hoops, axletree caps, loops, brace buckles, check rings, and door handles are generally plated. The beading, which is used to cover the joints, is of three kinds, brass, copper, and plated copper. It is formed by strips of metal being drawn into a circular or angular form by means of a die, the hollow space being filled with solder, into which small pins of pointed wire are fixed to attach it by. The brass beading is polished; the copper is painted, for which purpose the surface is roughened. As the quantity of beading used is often very considerable, the labour of silvering by means of a soldering iron would be too great, and therefore the plated or silvered beading is prepared from metal silvered in the sheet. The process is very simple:—A bar of copper being reduced to the proper thickness, a bar of silver is then united to it by means of heat. They are then passed through the rolls together, and occasionally annealed in the fire until the requisite thickness be obtained, the two metals spreading equally. This kind of metal is much used in the manufacture of carriage lamps.