PLACE OF NIGHT WORK IN INDUSTRY 5 
? 
Y 
refined corn products, soap, glue, drugs, perfumes, fine 
chemicals, electro-chemical industries, Louisiana cane 
sugar, refining of imported sugar, beet sugar, table salt, 
petroleum, cottonseed oil, linseed and other oils. 
Heavy Equipment Industries—Paper, flour, rubber,’ 
breakfast foods, batteries, automobiles, textiles,’ mines. 
Service Industries—Electricity power of all kinds, gas, 
water supply, ice, shipping, transportation, railroads, 
street railways, telegraph and telephone, mails and ex- 
press, policemen, firemen, watchmen. 
In the continuous industries, all the employees in the 
plants are not usually engaged in shift work. As a rule, the 
process men are on shift work, while mechanics on construc- 
tion and repair of equipment, common labor for loading and 
handling supplies, and the operatives in finishing depart- 
ments are generally at work only during the day. The pro- 
portion of men on shift duty was found to vary between 
109, of the entire force to almost 100%. In certain estab- 
lishments, such as, beet sugar refineries, practically the entire 
labor force is engaged in shift work. The number of workers 
on shift duty scheduled for night work was found to vary 
according to the nature of the process and the number of 
night shifts used. 
In addition to those industries where night work is essen- 
tial because of the continuous operation of the plant, there 
is another group of plants which supplement the output of 
the day force by the addition of a temporary or permanent 
night shift. In these cases there is a pause in operations be- 
tween shifts, although some of these plants may be continu- 
ously operative during a period of high business activity. For 
example, machine shops or printing establishments may 
organize night shifts either permanently or for special order 
work. Or, as is the case in many rubber manufacturing 
1 Only a few soap plants operate continuously. 
3 Some rubber plants operate continuously; others do so during production emer- 
gencies. 
3 Operated as continuous industry only in certain localities. 
t Some plants operate most of the twenty-four hours; others do so in certain 
periods. 
5 Not usually continuous.