THE PORTABLE LABORATORY 
67 
uncertain in their reactions than material substances; 
therefore, mere external uniformity in procedure, or stand- 
nrdization of laboratory technique and conditions, is by no 
means a guarantee that characteristic or typical reactions 
Wl h follow. For this reason it may be undesirable to 
construct a factory laboratory which will place the sub 
ject under conditions too different from the conditions 
of the place in which he is accustomed to work or undergo 
uis normal reactions. No one should understand the com 
plexity of this problem better than the psychologist him- 
Se lf- As a student of sensation and habit, he can readily 
understand that what he may consider & nice, quiet place 
! Tla y be, to the man accustomed to the continuous clank- 
ln g and grinding of machines, a place howling with strange 
an d fearful sounds. There are times when nothing makes 
So much noise as silence. 
This question, together with a great many others, must 
e considered by those conducting psychological experi 
ments under factory conditions. The portable laboratory 
v mch has been described is by no means a final or com 
prehensive one. However, as compared with a permanent 
^oratory such as is used in universities, it is a vast im- 
P lQ Vement. The stationary laboratory, except as a place 
111 which to develop and store apparatus, possesses and 
minifies all the difficulties mentioned. To recapitulate, 
^ makes it necessary to bring subjects long distances 
° m the shop in which they are working, thus involving 
a v cry considerable loss of time. The portable labora- 
. 0t 7 °bviates this difficulty by going to the shop in which 
proposed subjects are at work. Secondly, the sta- 
°Uary laboratory makes it difficult to secure the right 
ut) Jects at the right time. Psychologists who have tried 
universities to get students to report at the laboratory at