V 
THE PORTABLE LABORATORY 
One of the first essentials in scientific work of any kind 
is a laboratory. A laboratory is a place where work can be 
done under uniform and controlled conditions, and where 
the apparatus necessary for an experiment can be prop 
erly set up or stored. Most universities are equipped 
with a psychological laboratory differing little in general 
appearance from a physics laboratory. Whenever an ex 
periment is to be conducted in one of these laboratories, 
the apparatus is set up and, when preparations are com 
plete, the subjects who are to be tested are required to 
come to the laboratory according to a prearranged sched 
ule. For a time it was considered desirable to establish 
and equip a similar laboratory to be devoted exclusively 
to the psychological work of the factory. At first glance, 
such a laboratory would seem to be in line with the physi 
cal and chemical laboratories which now form an essential 
part of every large industry. However, it soon became 
obvious that such a laboratory was impracticable for 
factory purposes. It was highly inadvisable to ask a 
large number of employees to leave their work and come 
to the comparatively remote point occupied by the lab 
oratory. Not only would such a procedure have caused 
a great loss of time, but it would also have made inevi 
table a disconcerting uncertainty in the arrival of the 
expected subjects. And yet it was highly desirable to 
conduct experiments and tests under conditions of a cer