THE METAMORPHOSES OF CAPITAL AND THEIR CIRCUITSTHE TIME OF CIRCULATION [8]We have seen that the movement of capital through the sphere of production and the two phases of the sphere of circulation takes place in a series of periods of time. The duration of its sojourn in the sphere of production is its time of production, that of its stay in the sphere of circulation its time of circulation. The total time during which it describes its circuit is therefore equal to the sum of its time of production and its time of circulation.
The time of production naturally comprises the period of the labour-process, but is not comprised in it. It will be remembered first of all that a part of the constant capital exists in the form of instruments of labour, such as machinery, buildings, etc., which serve the same constantly repeated labour-processes until they are worn out. Periodical interruptions of the labour-process, by night for instance, interrupt the functioning of these instruments of labour, but not their stay at the place of production. They belong to this place when they are in function as well as when they are not. On the other hand the capitalist must have a definite supply of raw material and auxiliary material in readiness, in order that the process of production may take place for a longer or shorter time on a previously determined scale, without being dependent on the accidents of daily supply from the market. This supply of raw material, etc., is productively consumed only by degrees. There is, therefore, a difference between its time of production [9] and its time of functioning. The time of production of the means of production in general comprises, therefore, 1) the time during which they function as means of production, hence serve in the productive process; 2) the stops during which the process of production, and thus the functioning of the means of production embodied in it, are interrupted; 3) the time during which they are held in readiness as prerequisites of that process, hence already represent productive capital but have not yet entered into the process of production.
The difference so far considered has in each case been the difference between the time which the productive capital stays in the sphere of production and that it stays in the process of production. But the process of production may itself be responsible for interruptions of the labour-process, and hence of the labour-time -- intervals during which the subject of labour is exposed to the action of physical processes without the further intervention of human labour. The process of production, and thus the functioning of the means of production, continue in this case, although the labour-process, and thus the functioning of the means of production as instruments of labour, have been interrupted. This applies, for instance, to the grain, after it has been sown, the wine fermenting in the cellar, the labour-material of many factories, such as tanneries, where the material is exposed to the action of chemical processes. The time of production is here longer than the labour-time. The difference between the two consists in an excess of the production time over the labour-time. This excess always arises from the latent existence of productive capital in the sphere of production without functioning in the process of production itself or from its functioning in the productive process without taking part in the labour-process.
That part of the latent productive capital is held in readiness only as a requisite for the productive process, such as cotton, coal, etc., in a spinning-mill, acts as a creator of neither products nor value. It is fallow capital, although its fallowness is essential for the uninterrupted flow of the process of production. The buildings, apparatus, etc., necessary for the storage of the productive supply (latent capital) are conditions of the productive process and therefore constitute component parts of the advanced productive capital. They perform their function as conservators of the productive components in the preliminary stage. Inasmuch as labour-processes are necessary in this stage, they add to the cost of raw material, etc., but are productive labour and productive surplus-value, because a part of this labour, like of all other wage-labour, is not paid for. The normal interruptions of the entire process of production, the intermissions during which the productive capital does not function, create neither value nor surplus-value. Hence the desire to the work going at night, too. (Buch I, Kap. VIII, 4.) [English edition: Ch. X, 4. -- Ed .]
The intervals in the labour-time which the subject of labour must endure in the process of production itself create neither value nor surplus-value.
But they advance the product, form a part of its life, a process through which it must pass. The value of the apparatus, etc., is transferred to the product in proportion to the entire time during which they perform their function; the product is brought to this stage by labour itself, and the employment of these apparatus is as much a condition of production as is the reduction to dust of a part of the cotton which does not enter into the product but nevertheless transfers its value to the product. The other part of the latent capital, such as buildings, machinery, etc., the instruments of labour whose functioning is interrupted only by the regular pauses of the productive process -- irregular interruptions caused by the restriction of production, crises, etc., are total losses -- adds value without entering into the creation of the product. The total value which this part of capital adds to the product is determined by its average durability;it loses value, because it loses its use-value, both during the time that it performs its functions as well as during that in which it does not.