The following is taken from Engels on Capital (London, 1938) and transcribed by us
The necessary labour-time is given. The surplus labour is variable, but within certain limits. It can never = 0, since then capitalist production ceases. It can never go as high as 24 hours for physical reasons, and, moreover, the maximum limit is always affected by moral grounds as well. But these limits are very elastic. The economic demand is that the working day should be no longer than for normal wear and tear of the worker. But what is normal? An antimony results and only force can decide. Hence the struggle between the working class and the capitalist class for the normal working day (pp255-259).
Surplus value in former social eras. As long as the exchange-value is not more important than the use-value, surplus labour is milder, eg among the ancients; only where direct exchange-value – gold and silver – was produced, frightful surplus labour (p260). Likewise in the slave states of America until the production of quantities of cotton for export. Likewise corvee labour, eg in Roumania.
Corvee labour the best means of comparison with capitalist exploitation, because the former fixes and exhibits the surplus labour as a specific labour-time to be performed – Reglement organique of Wallachia (pp261-4).
The English Factory Acts are negative expressions of the greed for surplus labour, just as the foregoing were its positive expression. That of 1850 (p264) – 10.5 hours and 7.5 on Saturdays = 60 hours per week. Millowners’ profit through evasion (pp265-8).
Exploitation in unrestricted or only later restricted branches: lace industry (pp268-9), potteries (pp269-71), lucifer matches (pp271-2), wallpaper (pp272-3), baking (pp273-8), railway employees (pp278-9), seamstresses (pp280-1), blacksmiths (pp281-2). Day and night workers in shifts: (a) metallurgy and the metal industry (pp282-90).
These facts prove that capital regards the labourer as nothing else than labour-power, all of whose time is labour-time to the extent that this itself is at all possible at a given moment, and that the length of life of labour-power is immaterial to the capitalists (pp282-90). But is this not against the interests of the capitalist? What about the replacement of what is rapidly worn out? The organised slave trade in the interior of the United States has raised the rapid wearing out of slaves to an economic principle, exactly like the supply of labourers from the rural districts in Europe (pp2920-3). Poorhouse supply (p294). The capitalist sees only the continuously available surplus population and wears it out. Whether the race perishes – après lui le deluge. Capital is ruthless towards the health and length of life of the labourer, unless it is constrained to considerateness by society. . . and free competition makes the immanent laws of capitalist production hold good as an external compulsory law for the individual capitalist (pp296-7).
Establishment of a normal working day – the result of a century-old struggle between capitalist and worker.
At the beginning laws were made to raise working time; now to lower it (pp297-8). The first Statute of Labourers, 23 Edward III, 1349, under the pretext that the plague had so decimated the population that everyone had to do more work. Hence maximum wages and limit of the working day were fixed by law. In 1496, under Henry VII, the working day of agricultural labourers and all artificers from 5am to between 7 and 8pm in summer – March to September, with 1 hour, 1.5 hours and half an hour = 3 hours’ intermission. In winter from 5am to dark. This statute never strictly enforced. In the 18th century the whole week’s labour not yet available to capital (with the exception of agricultural labour). Cf controversies of that time (pp300-03). Only with large-scale industry was this and more achieved: it broke down all bounds and exploited the workers most shamelessly. The proletariat resisted as soon as it recovered its senses. The five acts of 1802-33 only nominal, since no inspectors. Only the Act of 1833 created a normal working day in the four textile industries: from 5.30am to 8.30pm, during which time young persons from 13 to 18 years of age could be employed only 12 hours with 1.5 hours’ pause, children from 9 to 13 years of age only 8 hours, while night work of children and young persons was prohibited (pp304-6).
The relay system and its abuse for purposes of evasion (p306). Finally, the Act of 1844 which put women of all ages on the same basis as young persons. Children limited to 6.5 hours; the relay system curbed. On the other hand, children permitted from 8 years on. At last in 1847 the ten-hour bill forced through for women and young persons (p311). The capitalists’ efforts against it (pp311-320). A flaw in the Act of 1847 led to the compromise Act of 1850 (pp320-1), which fixed the working day for young persons and women at 5 days of10.5, 1 day of 7.5 + 60 hours per week, moreover between 6 and 6 o’clock. Otherwise the Act of 1844 in force for children. The exception for the silk industry, cf p321. In 1853 the working time for children also limited to between 6 and 6 o’clock (p323).
Printworks Act – 1845, limits almost nothing – women and children can work 16 hours!
Dye works and bleaching works 1860. Lace factories 1861; potteries and many other branches 1863 (under the Factory Act); special acts passed the same year for bleaching in the open air and baking (pp324-5).
Large-scale industry thus at first creates the need for limiting working time, but it is later found that the same overwork has gradually taken possession of all other branches as well (pp326-7).
Moreover, history shows that the individual “free” labourer is defenceless against the capitalist, and succumbs, especially with the introduction of women’s and children’s labour, so that it is here that the class struggle develops between the workers and the capitalist (p327).
In France, the twelve-hour day law for all ages and branches of work only in 1848 (cf, however, p305), footnote on the French child labour law of 1841, which was really enforced only by 1853, and then only in the Department du Nord). Complete “freedom of labour” in Belgium. The eight-hour movement in America (p329).
Thus, the labourer comes out of the production process quite other than he entered. The labour contract was not the act of a free agent; the time for which he is at liberty to sell his labour is the time for which he is compelled to sell it, and only the mass opposition of the workers wins for them a state law that prevents the workers from selling themselves and their generation into slavery and death through voluntary contract with capital. The modest Magna Charta of the Factory Act takes the place of the grandiloquent catalogue of the inalienable rights of man (p330).
 We’ve changed spelling to English-English, thus labor becomes labour etc.
 All italics are as in the original.
 Engels provides page numbers for the first volume of Capital. He provides these for both the first edition of Capital published in Hamburg in 1867 and for the corresponding pages in the later American edition published by C.H. Kerr & Co. in Chicago. The editor of Engels on Capital (1938) checked the translation from the original German to the US edition, as the original US edition had a lot of translation errors.
 It’s interesting to see which sectors used long work weeks to maximise profits in Britain in the 1800s; for New Zealand today, see:
 This was undoubtedly true at the time, but things changed later. For instance, capital had to fight wars and required fit working class men to do this – the discovery that working class men in Britain were not in much of a fit state to fight in the Boer War led the ruling class to think more about the physical state of the working class. Later, the Great Depression saw a deterioration in the physical state of workers which also troubled the ruling class. These factors, along with struggles by workers, led to some social reforms to ensure a basic level of fitness among workers.
 Surplus population refers to the fact that people were being displaced from the land (by enclosures and by the mechanisation of agriculture) at a faster rate than the new urban industries could absorb them or the growing industrial cities could house them.
 After him, the deluge (1938 editor).
 While things have changed in the imperialist heartlands, as we pointed out above (endnote 4), this point by Engels largely holds true in the Third World. For a recent examination, see John Smith, Imperialism in the 21st century, New York, Monthly Review Press, 2016.
 While these changes were especially noticeable in the time periods to which Engels was referring, it appears that capitalism in the 21mt century is so clapped out that, even in the imperialist heartlands, the working week, after a century of shortening, has in recent decades generally been extended. For instance, in New Zealand, the 40-hour week, Monday-Friday, is a thing of the past for a large chunk of the working class. See:
 The relay system involved using shifts of children aged 9-13 which, between them would cover the permitted working day; this would also make it possible for adult millworkers to work 15-hour days.
 Limiting here means not reducing working time but simply setting the ambits.
 The “inalienable rights of man” was a central idea which the radical bourgeoisie had advanced in its tussle with the monarchies and aristocracies but moved away from once it settled into its position as the key part of the new ruling class. The economic needs of the new, dominant capitalist system simply could not coexist with such rights.