MERCURY-DIP CONTACT REVERSING SWITCH This switch was used for reversing the polarity of DC voltage circuits in reaction timing setups.
(MERCURY-DIP CONTACT REVERSING SWITCH; was used; for reversing the polarity of DC voltage circuits in reaction timing setups) (REVERSING SWITCH; [is] CONTACT [of]; DIP)
MERCURY-DIP CONTACT REVERSING SWITCH REVERSING SWITCH
was used [is] CONTACT [of]
for reversing the polarity of DC voltage circuits in reaction timing setups
DIP