The purification by liquation is assisted by poling the lead when it is below redness.
Liquation, if not followed by poling, is carried on as a rule in a reverberatory furnace with an oblong, slightly trough-shaped inclined hearth; if the lead is to be poled it is usually melted down in a cast-iron kettle.
The metal run off is further purified by poling, i.e.
By continuing the treatment of these in the ordinary way of refining, poling and granulating, all the foreign matters other than gold, copper and silver are removed, and, by exposing the granulated metal to a high oxidizing heat for a considerable time the copper may be completely oxidized while the precious metals are unaltered.
The American craft was propelled by poling, paddling, rowing, and by rude sails of matting.
This is effected by stirring the molten metal with a pole of green wood (" poling "); the products which arise from the combustion and distillation of the wood reduce the oxide to metal, and if the operation be properly conducted " tough-pitch " copper, soft, malleable and exhibiting a lustrous silky fracture, is obtained.
"This is slow work, Robert," said the older of the boys as they were poling up the river to a new fishing place.
"Oh, I have a plan for making a boat move without poling it or rowing it," he answered.
"It is better than poling the boat," said Christopher.