In most branches of industry proper, of mining, transportation, etc., operations proceed evenly, the working time being the same year in year out and the outlay of capital passing daily into the circulation process being uniformly distributed, apart from such abnormal interruptions as fluctuations of prices, business dislocations, etc. Likewise the return of the circulating capital or its renewal is evenly distributed throughout the year, market conditions otherwise remaining the same. Yet there is in the course of the various periods of the year the greatest inequality in the outlay of circulating capital in such capital investments in which the working time constitutes only a part of the production time, while the return takes place only in bulk at a time fixed by natural conditions. If the scale of business is the same, i.e., if the amount of advanced circulating capital is the same, it must be advanced in larger quantities at a time and for longer periods than in enterprises with continuous working periods. There is also a considerably greater difference here between the life of the fixed capital and the time in which it really functions productively. Due to the difference between working time and production time, the time of employment of the applied fixed capital is of course likewise continually interrupted for a longer or shorter time, for instance in agriculture in the case of working cattle, implements and machines. In so far as this fixed capital consists of draught animals, it requires continually the same, or nearly the same, expenditure for feed, etc., as it does during the time they work. In the case of dead stock non-use also brings on a certain amount of depreciation. Hence the product is in general increasing in price, since the transfer of value to it is not calculated according to the time during which the fixed capital functions but according to the time during which it depreciates in value. In branches of production such as these, the idling of the fixed capital, whether combined with current expenses or not, forms as much a condition of its normal employment as for instance the loss of a certain quantity of cotton in spinning; and in the same way the labour-power expended unproductively but unavoidably in any labour-process under normal technical conditions counts just as well as that expended productively. Every improvement which reduces the unproductive expenditure of instruments of labour, raw material, and labour-power also reduces the value of the product.