The additional capital serves merely the purpose of filling the gaps in the labour-process that arise on account of the time of circulation. Hence it is there simply to protect production against interruptions, originating in the time of circulation. Interruptions arising from the specific conditions of production are to be eliminated in another way, which need not be discussed at this point. There are however establishments in which work is carried on only intermittently, to order, so that there may be intervals between the working periods. In such cases, the need for additional capital is pro tanto eliminated. On the other hand in most cases of seasonal work there is a certain limit for the time of reflux. The same work cannot be renewed next year with the same capital, if the circulation time of this capital has not, in the meantime, run out. On the other hand the time of circulation may also be shorter than the interval between two periods of production. In that event the capital lies fallow, unless it is meanwhile employed otherwise.
Fourthly: The capital advanced for a certain working period --for instance the £600 in the third illustration -- is invested partly in raw and auxiliary materials, in a productive supply for the working period, in constant circulating capital, and partly in variable circulating capital, in the payment of labour itself. The portion laid out in constant circulating capital, may not exist for the same length of time in the form of a productive supply; the raw material for instance may not be on hand for the entire working period, coal may be procured only every two weeks.
However, as credit is still out of the question here, this portion of capital, in so far as it is not available in the form of a productive supply, must be kept on hand in the form of money so that it can be converted into a productive supply as and when needed. This does not alter the magnitude of the constant circulating capital-value advanced for 6 weeks. On the other hand -- regardless of the money-supply for unforeseen expenses, the reserve fund proper for the elimination of disturbances -- wages are paid in shorter intervals, mostly weekly. Therefore unless the capitalist compels the labourer to advance his labour for a longer time, the capital required for wages must be on hand in the form of money. During the reflux of the capital a portion must therefore be retained in money-form for the payment of the labour, while the remaining portion may be converted into productive supply.
The additional capital is divided exactly like the original. But it is distinguished from capital I by the fact that (apart from credit relations) in order to be available for its own working period it must advanced during the entire duration of the first working period of capital I, into which it does not enter. During this time it can already be converted, at least in part, into constant circulating capital, having been advanced for the entire period of turnover. To what extent it assumes this form or persists in the form of additional money-capital until this conversion becomes necessary, will depend partly on the special conditions of production of definite lines of business, partly on local conditions, partly on the price fluctuations of raw material, etc. If social capital is viewed in its entirety, a more or less considerable part of this additional capital will always be for a rather long time in the state of money-capital. But as for that portion of capital II which is to be advanced for wages, it is always converted only gradually into labour-power, as small working periods expire and are paid for. This portion of capital II, then, is available in the form of money-capital during the entire working period, until by its conversion into labour-power it take part in the function of productive capital.
Consequently, the accession of the additional capital required for the transformation of the circulation time of capital I into time of production, increases not only the magnitude of the advanced capital and the length of time for which the aggregate capital must necessarily be advanced, but also, and specifically so, that portion of the advanced capital which exists as money-supply, which hence exists in the state of money-capital and has the form of potential money-capital.
The same thing also takes place -- as far as it concerns both the advance in the form of a productive supply and in that of a money-supply -- when the separation of capital into two parts made necessary by the time of circulation, namely into capital for the first working period and replacement capital for the time of circulation, is not caused by the increase of the capital laid out but by a decrease of the scale of production.
The amount of capital tied up in the money-form grows here still more in relation to the scale of production.
What is achieved in general by this separation of capital into an originally productive and an additional capital is a continuous succession of the working periods, the constant function of an equal portion of the advanced capital as productive capital.
Let us look at the second illustration. The capital continuously employed in the process of production amounts to £500. As the working period is 5 weeks it operates ten times during 50 weeks (taken as a year).
Hence its product, apart from surplus-value, is 10 times £500, or £5,000. From the standpoint of a capital working directly and uninterruptedly in the process of production -- a capital-value of £500 -- the time of circulation seems to be brought to nought. The period of turnover coincides with the working period, and the time of circulation is assumed to be equal to zero.