Il me surprende a apprender que "logbook" non es de grec "log".  Secundo mi
Webster's

>Io ha me sovente demandate, "Proque iste 'log'?"  Io pensava que forsan in
>vetule dies le diarios sur le naves habeva coperturas de ligno.  Nunc, post
>le discussion herial del signification del serie ethymologic
>"leger--->logia", il me occurre le possibilitate que le anglese "log"
>poterea haber su origine in "-log-".  Alteremente dicite, un libro ubi on
>accomula (gather) informationes poterea ben logicamente portar le nomine
>"logbook" (gatherbook).
>
>-- frank

        log  n , often attrib [ME logge, prob. of Scand origin; akin to ON
     l¢g fallen tree; akin to OE licgan to lie ¦ more at LIE] (14c)
1        : a usu. bulky piece or length of unshaped timber; esp : a length of
     a tree trunk ready for sawing and over six feet (1.8 meters) long
2        : an apparatus for measuring the rate of a ship's motion through the
     water that consists of a block fastened to a line and run out
     from a reel
3
   a     : the record of the rate of a ship's speed or of her daily
      progress; also : the full nautical record of a ship's voyage
   b     : the full record of a flight by an aircraft
4        : a record of performance, events, or day-to-day activities <a computer É>

2.      log  vb  logged; logging vt (1699)
1
a        : to cut (trees) for lumber
b        : to clear (land) of trees in lumbering ¦ often used with off
2        : to make a note or record of : enter details of or about in a log
3
a        : to move (an indicated distance) or attain (an indicated speed)
      as noted in a log
b
(1)      : to sail a ship or fly an airplane for (an indicated distance
     or period of time)

Ecce hic es sufficiente.  Interessante, un parola possibile norvegian...

Stan Mulaik