Here are some of my test results for orientations of Morse Code to see if Palimpsest can be recovered.
#1 Straight 81, left to right across the rocks
Distance between P’s: 14 (or 67). 14-4 = 10. 10/5 = 2. Distance to nearest M =42 (or 39).
PreTatIutIsyOurP PTIISOP, the method does not recover palimpsest.
#2 Straight 81 Backwards, right to left across the rocks applying the palindrome concept that we read it from the other side to get a different message
Same as above, distance between P’s: 14 (or 67). 14-4 = 10. 10/5 = 2. Distance to nearest M =42 (or 39).
Due to the use of equal key lengths, the letters POSIITP are recovered (the reverse of the above).
It would be odd to consider a key-length of 2 because we should be able to “see” plaintext mixed with plaintext if we’re observant enough. All the same, it was not a number I picked but a product of the Morse Code string chosen.
#3 Straight 106 (with E’s), left to right across the rocks
Same as #1.
#4 Straight 106 (with E’s) backwards, right to left across the rocks applying the palindrome idea
Same as #2.
These are perhaps a better verdict that the key-length is not 2, with all of those strings of E’s the message would be garbled.
#5 Two Rows from left to right
Distance between P’s = 7, 7-4=3, 3/5 is not a whole number
I kind of like this one anyways so I’ll try and force it a little. If we try every fourth letter we get P-A-P-T-I-S-E-C-E-Y-D-T-I-U… we’ve skipped both M’s and have a C and no B (for abscissa).
Every 7th: PPIEE skips the M’s as well
#6 Two Rows from left to right with the E’s
Unfortunately, not much has changed between those two P’s. Perhaps we can retrieve an M?
Every fourth: PAPTEEVBOSEMEDTESRIAEHWUEQE
Can we get palimpsest out of that? No, there are no L’s.
Every 7th: PPEVOEE We end up skipping the M’s.