Incident readings are done using the white dome on the meter, without it you're reading reflected light.
For incident readings, you would usually point the meter towards the camera, though sometimes toward the light you're looking to expose for. Otherwise, for reflected readings point it at the surface or scene you want to measure. The incident readings and reflective readings will (should) match if you're metering a greycard, or at least be within 1/2 stop or so.
What sort of result does the Gossen give you if you do an incident reading in full sun for 100 ISO? Should be in the ballpark of 1/100 sec @f/16...