This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1881 Excerpt: ...As soon as the surface is covered the speed of deposition is greatly increased if the current be of proper strength. Then it follows that if a good strength of current be passing a corresponding amount of copper should be secured. It will, of course, be understood that as long as the actual facing is being deposited ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1881 Excerpt: ...As soon as the surface is covered the speed of deposition is greatly increased if the current be of proper strength. Then it follows that if a good strength of current be passing a corresponding amount of copper should be secured. It will, of course, be understood that as long as the actual facing is being deposited the work will be slow unless the electro-motive force be increased. There is no economy in increasing the current during this stage of the process. When the word current is used here it signifies the actual current, not the current which might pass if the resistance and distance apart were reduced. Thus, the currents yielded by a battery when on short circuit and when depositing copper are very different in strength. Work of any kind always reduces the current, and it is the amount of electrical energy actually passing that we have to deal with. Hence the work or depositing rate may be taken to be proportionate to the actual current. A rise of temperature will increase the current by decreasing the resistance. Dirty Anodes.--It may prove both interesting and instructive to give some particulars of the cause of the films observed on copper anodes. They are usually brown or black in colour, and appear on the dissolving surface in proportion to the amount of copper withdrawn. This dirt is a source of great trouble to the operator, because it not only necessitates frequent cleaning of the anode, but falls to the bottom of the vat, and when disturbed is apt to get upon or into the moulds. If the plan recommended by the author--that of using only Daniell cells and employing their electrotype copper for anodes--were once tried, it would probably be always used, because the copper is quite free from the foreign matters spoken of as dirt. A chemist on an...
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PLEASE NOTE, WE DO NOT SHIP TO DENMARK. New Book. Shipped from UK in 4 to 14 days. Established seller since 2000. Please note we cannot offer an expedited shipping service from the UK.
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PLEASE NOTE, WE DO NOT SHIP TO DENMARK. New Book. Shipped from UK in 4 to 14 days. Established seller since 2000. Please note we cannot offer an expedited shipping service from the UK.
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Seller's Description:
PLEASE NOTE, WE DO NOT SHIP TO DENMARK. New Book. Shipped from UK in 4 to 14 days. Established seller since 2000. Please note we cannot offer an expedited shipping service from the UK.
