At the top are a number of columns; TRK = track to fly; DIS = distance to run on that leg; VARN = the magnetic variation between magnetic north and true north at that point on the map (it is a correction to apply to the compass heading).  In the main body of the log there are columns for the TR REQ = track required and the Co St'd = course steered.  In each case they are the same either indicating that there was no wind or that Frank was not taking account of one.  In the main body of the text S/C = Set Course and A/C = Alter Course.  There are references to 7/10 & 10/10 clouds.  10/10 means total and complete cloud cover.  Today aircrew and air traffic talk in terms of 'eighths' or 'octals' to indicate cloud cover; so 8/8 is now the equivalent of 10/10.  Don't ask me why it moved from base 10 to base 8!