- Go behind the control room desk and check that the black rheostat is dialed down to zero
- Flip the switch next to it to ''On''
- Dial the rheostat up to 220 V (do not exceed that value as you will blow the lamps)
- The lamps on the top end of the telescope should now be on
- When you have the flats, slew the telescope back to the zenith (again keeping an eye on the cables)
- Dial the rheostat down to zero
- Flip the switch to ''Off''
- Close the mirror cover