“Working time is always production time, that is to say, time during which capital is held fast in the sphere of production. But vice versa, not all time during which capital is engaged in the process of production is necessarily working time.” (p 242)
Take forestry. The working period consists of that time required to clear the land to be planted, to prepare it, to plant seedlings, to erect fencing etc. It also consists of the time required to cut down mature trees, to transport them to the saw-mill, strip them, and cut them. But, between these two labour processes – that in respect of the working period constitute one continuous process – there could be an interval of 100 years! During that time, labour may not be needed at all, or only occasionally, and in small amounts. During that time, however, the production process continues, because the trees grow as part of a natural, organic process.
Consequently, the production-time here, is considerably longer than the working period. Its not just natural processes that this applies to. It applies to various chemical processes too. Wine needs time to ferment, pottery to dry etc.
“But the product is not finished, not ready, hence not fit to be converted from the form of productive into that of commodity-capital until the production period is completed. Consequently the length of the turnover period increases in proportion to the length of the production time that does not consist of working time.” (p 243)
If the production time is not fixed, as a result of natural processes, the turnover time can be reduced by shortening the production-time. An example is the introduction of chemical bleaching.
“The most magnificent illustration of an artificial abbreviation of the time of production taken up exclusively with natural processes is furnished by the history of iron manufacture, more especially the conversion of pig iron into steel during the last 100 years, from the puddling process discovered about 1780 to the modern Bessemer process and the latest methods introduced since. The time of production has been brought down tremendously, but the investment of fixed capital has increased in proportion.
A peculiar illustration of the divergence of the production time from the working time is furnished by the American manufacture of shoe-lasts. In this case a considerable portion of the unproductive costs arises from having to hold the timber at least eighteen months before it is dry enough to work, so as to prevent subsequent warping. During this time the wood does not pass through any other labour-process. The period of turnover of the invested capital is therefore not determined solely by the time required for the manufacture of the lasts but also by the time during which it lies unproductive in the shape of drying wood. It stays 18 months in the process of production before it can enter into the labour-process proper. This example shows at the same time that the times of turnover of different parts of the aggregate circulating capital may differ in consequence of conditions which do not arise within the sphere of circulation but owe their origin to the production process.” (p 243)