CHAPTER XX 
JAPANESE ALLOYS 
Mizu-nagashi—Mokume—Shaku-do—Sliibu-ichi. 

. Something akin to inlaying is the Japanese work in banded * alloys. The late Sir William Chandler Roberts-Austen was the first in this country to describe the work in valuable papers read before the British Association and the Society of Arts more than twenty years ago. But it is still little known or practised. 

The Japanese workman takes thin plates of various metals or alloys—gold, silver, copper, and various alloys of these metals—and solders them together. In the thickish plate thus produced conical holes are bored, or grooves cut, as shown in Fig. 271. These cuts penetrate the various laj^ers and expose them in rings or bands. The plate is then hammered flat in front. Or the thick plate is hammered or rolled out thin, and then beaten up irregularly from behind with repousse tools. The bumps in front are then filed fiat, and parts of the-various layers of which the plate is composed become visible in front. The different strata exposed form an irregular marbled pattern. The work is known as mizu-nagashi. Another variety is called " mokume " (wood grain). It is made from alternate layers of light and dark coloured metal,—the effect of wood grain being exactly imitated. 

Work of this kind can be used to give interest and colour to an otherwise plain surface. It is not difficult to produce. The various sheets of metal to be used should be rolled down to size 1 on the metal gauge, or even thinner. They should then be boiled out in pickle, again in a solution of washing soda and water, and lastly in clean water. They should then be held by the edges only,—for to touch their flat surfaces with the hand might leave a trace of grease, whioh would interfere with the soldering. Now paint all their surfaces with borax and tie the plates together with wire. Lay paillons of silver solder all along two adjacent sides and heat till the solder has run through all the joints. The plate may now be folded on itself to make it double the thickness, and the two halves soldered together. It will of course havetwiceasmanylayersasit hadatfirst. Thisprocessof doubling the plate and soldering it may be repeated as often as desired. The resulting thick plate may be rolled out afterwards. It will consist of a large number of thin layers of the various metals used, all united by solder. The back of the plate can now be beaten to drive up bumps in front. These may form regular patterns if desired, or be quiteirregularly shaped. Holes may then be drilled into the plateexposing the various layers. The bumps are then filed flat with a similar result. Should you file right through the plate at any of these places it will not matter much, for pieces of metal may be soldered into the holes from the back. The plate is then hammered flat. It may requireannealing. Its surface will be composed of irregularlyshaped bars, stripes, rings and spots of the various metals employed, giving a delightful mottled appearance. 

An interesting variety of this work can be produced as follows. Take thin wires of various metals and twist them to form a cord. Coil this upon itself into a spiral. Solder the coils together. Beat or file the surface flat. The patternproduced is a curious spiral of various coloured metals, Fig. 272.

The Japanese use a number of alloys for this and other work. The two principal ones are known as— 
1. Shaku-do. This is composed of copper with lj to 4 per cent, of gold, and traces of silver, lead, etc. The addition of this small proportion of gold, enables the copper totakea beautifulpurplecolour whenpickledinthe solution 
given on page 263.  
2. The second alloy is known as Shibu-ichi. It is com posed of 2 parts copper, 1 part silver, and traces of gold and iron; or of about equal parts of copper and silver and a trace of gold. It takes a fine silver-grey colour. The 
use of these alloys, each of which is made in several different shades gives to the Japanese craftsman a much wider range of colour than is generally open to his European brother. For to the Japanese artist the intrinsic value of the material employed counts but little in comparison with its artistic or colour value. To him, fortunately, hallmarking is unknown.