rim or flange attached to, and passing all around its upper edge. Upon this rim is fixed a rectangle of brass tubing, to which is soldered a binding screw connecting it with the positive pole of the battery. Inside of this rectangle is attached another smaller rectangle of brass tubing, passing all around the flange like the first, the two being completely insulated from each other. This second rectangle also has a binding-screw, which serves to connect it with the negative pole of the battery. Rods or tubes of brass placed transversely rest with their extremities in clean metallic contact with the outer or larger rectangle, and these are destined to support, and are in good metallic contact with, a number of sheet silver anodes by frames of iron, which extend down into the bath. Other rods of brass, also lying crosswise like those just mentioned, rest with their extremities in the inner and smaller rectangle, and from these are supported by means of wires the objects to be silvered. By using a flange slightly inclined upwards, or provided with a step, the outer rectangle will be placed somewhat higher than the inner one, so that cross-rods carrying the anode will cross without touching the lower-lying inner rectangle. The same object will also be accomplished by using a larger tubesay one inch in diameter-for the outer rectangle, and a smaller one, one-half inch, for the inner one. It is scarcely necessary to add that all the points of contact of the cross tubes with the rectangles, the supporting frames, and the suspension wires with the cross tubes, and the binding-screw and other connections, must be kept scrupulously clean, and for this purpose must be frequently examined.

Having provided a vat of this description, a certain number of spoons, forks, etc., fixed to one of the cross tubes (Fig. 114), by means of copper wires, are cleansed at the

same time, and the tube is placed in position with its extremities resting on the inner or negative rectangle of the bath. Then with its ends resting upon the positive conductor of the trough and adjacent to the first a second cross tube is placed in position, to which is attached a silver anode (Fig. 115).

Fig. 114.

Fig. 115.

Next comes another series of spoons and forks, faced by another anode, and so on, in such a manner that each series of articles is disposed between two anodes. The cross tubes carrying the articles to be silvered all rest, of course, upon the negative conductor, and the anodes upon the positive.

This disposition is evidently the best for obtaining a sensibly equal deposit upon all the pieces; nevertheless, unless the articles are kept in constant motion, it will be found necessary to reverse the objects during the ope ration (i. e., turn them upside down) in order that the lower portions shall not receive the heaviest deposit. This will otherwise be the case as the richest part of the solution is the densest, and therefore lies near the bottom of the vat. Moreover, the change of position of the articles prevents the formatian of longitudinal striæ, which are often seen upon smooth articles left undisturbed in the solution for a long time.

These striæ are generally due to the existence of a multitude of small, convection currents, ascending and descending side by side, and formed by the successive displacement of denser and lighter liquid layers. They do not occur in liquids kept in a state of constant agitation. The denser layers, being richer in metal, deposit it more abundantly in the direction which they follow, and form grooves which cannot be filled by the lighter and poorer currents. It is, therefore, advantageous either to keep the bath, or the objects, in constant motion; and in large. plating works, where motive power is available, a small portion of it may be used for imparting a swinging motion

supporting the articles does not rest upon the vat, but is suspended above the bath, and receives a slow swinging motion from a small eccentric or its equivalent (Fig. 116).

Any other mechanical movement, producing the same results, may be employed.

The amount of silver deposited on plated goods varies according to circumstances. Different establishments have several grades of goods which they designate by special trademarks. A coating of the thickness of common writing-paper, which is considered to be an excellent one, corresponds to about an ounce and a quarter, or an ounce and a half of silver to the square foot of surface. The silver will adhere strongly, if the articles have been properly prepared before plating.

Where the voltaic battery is used as the generator of the current, the time required for laying a satisfactory coat of silver will vary, according to the grade of the plating required, from three or four hours to twelve hours. With the dynamo-electric machine, however, which has come into almost universal use in the larger plating establishments, a fair coating can be laid in three-quarters of an hour, and a heavy coat (triple-plate) in from two to three hours, according to the intensity of the current, the condition of the bath, and the relative proportions between the surfaces of anode and cathode.

The practice obtains among a few platers of removing their articles from the bath after they have received a thin coating of silver, thoroughly scratch-brushing, and returning them. It is questionable, however, if the advantages supposed to be gained by this practice are sufficient to warrant the extra labor, and to offset the risk of spotting the articles with finger marks. As one very experienced plater expressed himself to us on the subject, it is "love's labor lost."

In order to secure an extra heavy coating of silver on the convex surfaces of spoons and forks, which, being subject to greater wear than the other parts, require extra

protection, the Meriden Britannia Company uses a frame in which the articles, supported therein by their tips, are placed horizontally in a shallow silver bath, and immersed just deep enough to allow the projecting convexities to dip into the bath. By this artifice, these portions are given a second coating of silver of any desired thickness. This mode of procedure, which is termed "sectional plating," accomplishes the intended purpose, simply and satisfactorily. The common plan, elsewhere named, of allowing the backs of these articles to face the anode for a longer time than the front, has the obvious objection that it necessitates the deposition of an unnecessarily heavy coating upon the other portions of the same surface exposed to the anode. Similar devices are in use in other establishments.

The following tabulation exhibits the amount of silver deposited upon the several grades of plated tableware manufactured by the William Rogers Manufacturing Company, of Hartford, Conn.

Electro-silvering baths do not generally work so well when freshly prepared as after they have been used for a certain time, and have become electrolyzed; the deposit is not always uniform, and is often granulated, bluish, or yellowish. When this is the case, it will be found useful to mix a portion of old baths with those recently prepared. New baths may be artificially aged by boiling them for a few hours, or by adding to them one or two thousandths of aqua ammonia.

The greatest reproach to electro-silver-plating is that the deposit does not retain its color, but becomes yellow