An extremely rare cancelation on Helgoland stamps which is often illustrated by the image above (Fig 1).
It appears there were two versions of this cancelation and that the stamp illustrated is cancelled with the second version (Fig 2). The obvious differences between the 2 cancelations can be summed up as:
Fig 1: Sold straight line between day & month and curved numbers for hours of the day
Fig 2: Broken line between day & month and hours of the day in a straight line
The only other example I could find of this cancelation used on a Helgoland stamp
was in Lars Peter Svendsen’s Gold Medal Helgoland Collection and was accompanied by this text:
“Only 4 stamps with this postmark registered.”
The question now is, could this be #5?