PRESIDENTIAL ADDRESS. 543 
standing of haviiig recourse to abstraction ; it is a method without which 
every scientific study, whether philosophy, biology, physics, or what not, 
even history, would be impossible. In the first instance, therefore, I intend 
to indicate the length of working day which operatives and employers 
would respectively seek if they recognised their own interests and were 
endowed with complete foreknowledge of the effects of different hours of 
labour upon their interests. I shall assume—as I may legitimately for 
ordinary factory employment—that the workman tends to get as his wage 
his marginal worth, that is to say, the value which would be lost by his 
dismissal. We may assume, further, that the marginal worth of the 
workman for any given working day becomes in the long run a stationary 
amount. If the efficiency of labour rose continuously in consequence of a 
reduction of hours it would obviously approximate to some limit, and if it 
fell continuously in consequence of an extension of the hours of labour it 
would equally approximate to a limit. After some time the differences 
between these limits and the actual efficiency of labour could be taken as 
negligible. Merely for the sake of simplicity, I shall now suppose that 
one kind of labour only is employed. It is clear, then, that it is possible 
on these assumptions to indicate what in the long run (7.e., when all the 
reactions, as regards, for instance, the efficiency of labour and provision 
and arrangement of other agents, have taken place) the marginal daily 
worth of labour will be for different lengths of working day, it being under- 
stood that the number of shifts worked remains the same. If the number 
of shifts were increased the value of the labour would rise, as will be fully 
explained later. Let us suppose that the following table represents, at a 
given time, the value of labour of a given kind per week in relation to the 
length of the working day :— 
Value of Labour 
Hours per Day. per Week in Shillings, 
6 » ° 34 
7 38 
8 . : 40 
9 - 5 41 
10 . . ° 40 
11 . . ' 39 
12 - ° : 37 
The fall in the value of labour after the working day exceeds nine hours 
is due to the fact that diminished weekly productivity more than counteracts 
the direct effect of the extension of the daily time for work. The diminished 
weekly productivity may be due to impaired vitality—physical, mental, or 
moral—or to some extent to irregularity, where that is possible, as in the 
case of colliers. The damage to productivity may be inflicted dizectly by 
excessive work, or it may be indirectly consequent upon it, the prime cause 
being found in the use of stimulants or recourse to unhealthy excitement in 
periods of leisure, reactions which are only to be expected when the day’s 
work is very exhausting or very dull. The use of leisure affects, of course, 
mental vitality, culture, and character, and it will therefore be generally 
observable that labour which has had its hours reduced will be capable after 
a time—when the use of leisure has been improved and the improvement has 
produced its effects—of managing satisfactorily more complicated machinery, 
and will be generally more responsible and trustworthy, and therefore less 
in need of continuous watching and directing. Now, clearly, if employers 
are endowed with the foresight presupposed, and if their hours of work 
need not increase concurrently with a lengthening of the working day, it is 
in the case supposed to their interest collectively to come to an agreement 
not to employ labour more than nine hours a day, and to their interest 
individually not to employ labour for shorter hours than nine a day. The 
second conclusion follows from the fact that the weekly product would be 
