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Connections

Having a knowledge of the theoretical action of the battery, the next question is the connections. Cleanliness cannot be too strongly insisted upon in making joints, etc. The plater should make it an invariable rule to see that all surfaces of wires, screws, etc., through which the current must pass, be kept bright on the surfaces, through which electrical contact is made. When joining wires they should be brightened with a file, or with emery cloth, and then twisted firmly together with a pair of pliers; all permanent connections should be carefully soldered and the holes and the ends of screws in binding posts should be kept bright; and if for permanent use all conducting wires should be of pure copper, well insulated. The following tables shows in the last column the loss of current in wires carrying an economical amount of current; if the wire be too small this loss is rapidly quadrupled until the wire burns. The economy of using large and short connections will be apparent after a slight study of this table. Table showing the Weight, Carrying Capacity and Loss in Volts of different sizes Copper Wire.

Brown & Sharpe's Gauge No. Diameter in Thousandths of an inch. Pounds per 1000 feet bare wire. Approximate weight Underwriters' Insulation, per 1000 feet. Safe Current in Amperes. Loss in Volts per Ampere per 100 feet of line (2 Wire.) 0000 .46 640.5 825 lbs. 312. .0098 000 .40964 508.5 610 lbs. 262. .0123 00 .3648 402.8 458 lbs. 220. .0155 0 .32495 319.6 385 lbs. 185. .0196 1 .2893 253.4 308 lbs. 156. .0247 2 .25763 201.0 249 lbs. 131. .0311 3 .22942 159.3 201 lbs. 110. .0392 4 .20431 126.4 163 lbs. 92.3 .0495 5 .18194 100.2 133 lbs. 77.6 .0624 6 .16202 79.46 109 lbs. 65.2 .0787 7 .14428 63.01 90 lbs. 54.8 .0992 8 .12849 49.98 74 lbs. 46.1 .125 9 .11443 39 64 62 lbs. 38.7 .158 10 .10189 31.43 52 lbs. 32.5 .199 11 .090742 24.93 43 lbs. 27.3 .251 12 .080808 19.77 36 lbs. 23. .316 13 .071961 15.68 30 lbs. 19.3 .399 14 .064084 12.43 25 lbs. 16.2 .503 15 .057068 9.86 21 lbs. 13.6 .634 16 .05082 7.82 18 lbs. 11.5 .799 17 .045257 6.20 15 lbs. 9.6 1.088 18 .040303 4.92 13 lbs. 8.1 1.271 No matter what battery be used, there are several preliminary conditions that must be complied with in order to produce satisfactory results, i.e. that the deposition may adhere firmly and take place uniformly. It is absolutely necessary that the pure metallic surface of the article be exposed, and that it be perfectly free from grease. The articles to be plated, if lustrous surfaces are desired, must first be ground and polished. The grease must be removed from the surface by boiling in potash or caustic soda, and this is followed by scouring with freshly burnt lime, pulverized thoroughly and free from all grit. If the article will not stand heat, cleanse with benzine. In order to free the surface of non-metallic substances, if the article be of iron, steel or silver, dip it in a mixture of 1 part by weight of sulphuric acid, to 15 of water; if copper or brass, the articles are first dipped in dilute sulphuric acid, and then in a mixture of 100 parts, by weight, of nitric acid, 50 of sulphuric acid, 1 of common salt and 1 of soot. As soon as the surface of the article assumes a bright appearance, it is washed in clean water once or twice, avoiding handling with the fingers or greasy cloths. Wooden plyers, kept clean, serve well for handling.

Avoid the injurious fumes produced by the acids, by operating in the open air or in the draft of a chimney. In order to determine whether the article is entirely free from grease, dip it into water, and if all grease is removed, the water will adhere uniformly; if, however, lines and spots appear, the article is not thoroughly clean, and must again be put through the cleasing process.